corpus_parole: comparison cms/drupal/includes/form.inc

equal deleted inserted replaced

-:07239de796bb
+:e756a8c72c3d
+<?php
+/**
+* @file
+* Functions for form and batch generation and processing.
+*/
+/**
+* @defgroup forms Form builder functions
+* @{
+* Functions that build an abstract representation of a HTML form.
+*
+* All modules should declare their form builder functions to be in this
+* group and each builder function should reference its validate and submit
+* functions using \@see. Conversely, validate and submit functions should
+* reference the form builder function using \@see. For examples, of this see
+* system_modules_uninstall() or user_pass(), the latter of which has the
+* following in its doxygen documentation:
+* - \@ingroup forms
+* - \@see user_pass_validate()
+* - \@see user_pass_submit()
+*
+* @}
+*/
+/**
+* @defgroup form_api Form generation
+* @{
+* Functions to enable the processing and display of HTML forms.
+*
+* Drupal uses these functions to achieve consistency in its form processing and
+* presentation, while simplifying code and reducing the amount of HTML that
+* must be explicitly generated by modules.
+*
+* The primary function used with forms is drupal_get_form(), which is
+* used for forms presented interactively to a user. Forms can also be built and
+* submitted programmatically without any user input using the
+* drupal_form_submit() function.
+*
+* drupal_get_form() handles retrieving, processing, and displaying a rendered
+* HTML form for modules automatically.
+*
+* Here is an example of how to use drupal_get_form() and a form builder
+* function:
+* @code
+* $form = drupal_get_form('my_module_example_form');
+* ...
+* function my_module_example_form($form, &$form_state) {
+*   $form['submit'] = array(
+*     '#type' => 'submit',
+*     '#value' => t('Submit'),
+*   );
+*   return $form;
+* }
+* function my_module_example_form_validate($form, &$form_state) {
+*   // Validation logic.
+* }
+* function my_module_example_form_submit($form, &$form_state) {
+*   // Submission logic.
+* }
+* @endcode
+*
+* Or with any number of additional arguments:
+* @code
+* $extra = "extra";
+* $form = drupal_get_form('my_module_example_form', $extra);
+* ...
+* function my_module_example_form($form, &$form_state, $extra) {
+*   $form['submit'] = array(
+*     '#type' => 'submit',
+*     '#value' => $extra,
+*   );
+*   return $form;
+* }
+* @endcode
+*
+* The $form argument to form-related functions is a structured array containing
+* the elements and properties of the form. For information on the array
+* components and format, and more detailed explanations of the Form API
+* workflow, see the
+* @link forms_api_reference.html Form API reference @endlink
+* and the
+* @link http://drupal.org/node/37775 Form API documentation section. @endlink
+* In addition, there is a set of Form API tutorials in
+* @link form_example_tutorial.inc the Form Example Tutorial @endlink which
+* provide basics all the way up through multistep forms.
+*
+* In the form builder, validation, submission, and other form functions,
+* $form_state is the primary influence on the processing of the form and is
+* passed by reference to most functions, so they use it to communicate with
+* the form system and each other.
+*
+* See drupal_build_form() for documentation of $form_state keys.
+*/
+/**
+* Returns a renderable form array for a given form ID.
+*
+* This function should be used instead of drupal_build_form() when $form_state
+* is not needed (i.e., when initially rendering the form) and is often
+* used as a menu callback.
+*
+* @param $form_id
+*   The unique string identifying the desired form. If a function with that
+*   name exists, it is called to build the form array. Modules that need to
+*   generate the same form (or very similar forms) using different $form_ids
+*   can implement hook_forms(), which maps different $form_id values to the
+*   proper form constructor function. Examples may be found in node_forms(),
+*   and search_forms(). hook_forms() can also be used to define forms in
+*   classes.
+* @param ...
+*   Any additional arguments are passed on to the functions called by
+*   drupal_get_form(), including the unique form constructor function. For
+*   example, the node_edit form requires that a node object is passed in here
+*   when it is called. These are available to implementations of
+*   hook_form_alter() and hook_form_FORM_ID_alter() as the array
+*   $form_state['build_info']['args'].
+*
+* @return
+*   The form array.
+*
+* @see drupal_build_form()
+*/
+function drupal_get_form($form_id) {
+$form_state = array();
+$args = func_get_args();
+// Remove $form_id from the arguments.
+array_shift($args);
+$form_state['build_info']['args'] = $args;
+return drupal_build_form($form_id, $form_state);
+}
+/**
+* Builds and process a form based on a form id.
+*
+* The form may also be retrieved from the cache if the form was built in a
+* previous page-load. The form is then passed on for processing, validation
+* and submission if there is proper input.
+*
+* @param $form_id
+*   The unique string identifying the desired form. If a function with that
+*   name exists, it is called to build the form array. Modules that need to
+*   generate the same form (or very similar forms) using different $form_ids
+*   can implement hook_forms(), which maps different $form_id values to the
+*   proper form constructor function. Examples may be found in node_forms(),
+*   and search_forms().
+* @param $form_state
+*   An array which stores information about the form. This is passed as a
+*   reference so that the caller can use it to examine what in the form changed
+*   when the form submission process is complete. Furthermore, it may be used
+*   to store information related to the processed data in the form, which will
+*   persist across page requests when the 'cache' or 'rebuild' flag is set.
+*   The following parameters may be set in $form_state to affect how the form
+*   is rendered:
+*   - build_info: Internal. An associative array of information stored by Form
+*     API that is necessary to build and rebuild the form from cache when the
+*     original context may no longer be available:
+*     - args: A list of arguments to pass to the form constructor.
+*     - files: An optional array defining include files that need to be loaded
+*       for building the form. Each array entry may be the path to a file or
+*       another array containing values for the parameters 'type', 'module' and
+*       'name' as needed by module_load_include(). The files listed here are
+*       automatically loaded by form_get_cache(). By default the current menu
+*       router item's 'file' definition is added, if any. Use
+*       form_load_include() to add include files from a form constructor.
+*     - form_id: Identification of the primary form being constructed and
+*       processed.
+*     - base_form_id: Identification for a base form, as declared in a
+*       hook_forms() implementation.
+*     - immutable: If this flag is set to TRUE, a new form build id is
+*       generated when the form is loaded from the cache. If it is subsequently
+*       saved to the cache again, it will have another cache id and therefore
+*       the original form and form-state will remain unaltered. This is
+*       important when page caching is enabled in order to prevent form state
+*       from leaking between anonymous users.
+*   - rebuild_info: Internal. Similar to 'build_info', but pertaining to
+*     drupal_rebuild_form().
+*   - rebuild: Normally, after the entire form processing is completed and
+*     submit handlers have run, a form is considered to be done and
+*     drupal_redirect_form() will redirect the user to a new page using a GET
+*     request (so a browser refresh does not re-submit the form). However, if
+*     'rebuild' has been set to TRUE, then a new copy of the form is
+*     immediately built and sent to the browser, instead of a redirect. This is
+*     used for multi-step forms, such as wizards and confirmation forms.
+*     Normally, $form_state['rebuild'] is set by a submit handler, since it is
+*     usually logic within a submit handler that determines whether a form is
+*     done or requires another step. However, a validation handler may already
+*     set $form_state['rebuild'] to cause the form processing to bypass submit
+*     handlers and rebuild the form instead, even if there are no validation
+*     errors.
+*   - redirect: Used to redirect the form on submission. It may either be a
+*     string containing the destination URL, or an array of arguments
+*     compatible with drupal_goto(). See drupal_redirect_form() for complete
+*     information.
+*   - no_redirect: If set to TRUE the form will NOT perform a drupal_goto(),
+*     even if 'redirect' is set.
+*   - method: The HTTP form method to use for finding the input for this form.
+*     May be 'post' or 'get'. Defaults to 'post'. Note that 'get' method
+*     forms do not use form ids so are always considered to be submitted, which
+*     can have unexpected effects. The 'get' method should only be used on
+*     forms that do not change data, as that is exclusively the domain of
+*     'post.'
+*   - cache: If set to TRUE the original, unprocessed form structure will be
+*     cached, which allows the entire form to be rebuilt from cache. A typical
+*     form workflow involves two page requests; first, a form is built and
+*     rendered for the user to fill in. Then, the user fills the form in and
+*     submits it, triggering a second page request in which the form must be
+*     built and processed. By default, $form and $form_state are built from
+*     scratch during each of these page requests. Often, it is necessary or
+*     desired to persist the $form and $form_state variables from the initial
+*     page request to the one that processes the submission. 'cache' can be set
+*     to TRUE to do this. A prominent example is an Ajax-enabled form, in which
+*     ajax_process_form() enables form caching for all forms that include an
+*     element with the #ajax property. (The Ajax handler has no way to build
+*     the form itself, so must rely on the cached version.) Note that the
+*     persistence of $form and $form_state happens automatically for
+*     (multi-step) forms having the 'rebuild' flag set, regardless of the value
+*     for 'cache'.
+*   - no_cache: If set to TRUE the form will NOT be cached, even if 'cache' is
+*     set.
+*   - values: An associative array of values submitted to the form. The
+*     validation functions and submit functions use this array for nearly all
+*     their decision making. (Note that #tree determines whether the values are
+*     a flat array or an array whose structure parallels the $form array. See
+*     @link forms_api_reference.html Form API reference @endlink for more
+*     information.) These are raw and unvalidated, so should not be used
+*     without a thorough understanding of security implications. In almost all
+*     cases, code should use the data in the 'values' array exclusively. The
+*     most common use of this key is for multi-step forms that need to clear
+*     some of the user input when setting 'rebuild'. The values correspond to
+*     $_POST or $_GET, depending on the 'method' chosen.
+*   - always_process: If TRUE and the method is GET, a form_id is not
+*     necessary. This should only be used on RESTful GET forms that do NOT
+*     write data, as this could lead to security issues. It is useful so that
+*     searches do not need to have a form_id in their query arguments to
+*     trigger the search.
+*   - must_validate: Ordinarily, a form is only validated once, but there are
+*     times when a form is resubmitted internally and should be validated
+*     again. Setting this to TRUE will force that to happen. This is most
+*     likely to occur during Ajax operations.
+*   - programmed: If TRUE, the form was submitted programmatically, usually
+*     invoked via drupal_form_submit(). Defaults to FALSE.
+*   - programmed_bypass_access_check: If TRUE, programmatic form submissions
+*     are processed without taking #access into account. Set this to FALSE
+*     when submitting a form programmatically with values that may have been
+*     input by the user executing the current request; this will cause #access
+*     to be respected as it would on a normal form submission. Defaults to
+*     TRUE.
+*   - process_input: Boolean flag. TRUE signifies correct form submission.
+*     This is always TRUE for programmed forms coming from drupal_form_submit()
+*     (see 'programmed' key), or if the form_id coming from the $_POST data is
+*     set and matches the current form_id.
+*   - submitted: If TRUE, the form has been submitted. Defaults to FALSE.
+*   - executed: If TRUE, the form was submitted and has been processed and
+*     executed. Defaults to FALSE.
+*   - triggering_element: (read-only) The form element that triggered
+*     submission. This is the same as the deprecated
+*     $form_state['clicked_button']. It is the element that caused submission,
+*     which may or may not be a button (in the case of Ajax forms). This key is
+*     often used to distinguish between various buttons in a submit handler,
+*     and is also used in Ajax handlers.
+*   - clicked_button: Deprecated. Use triggering_element instead.
+*   - has_file_element: Internal. If TRUE, there is a file element and Form API
+*     will set the appropriate 'enctype' HTML attribute on the form.
+*   - groups: Internal. An array containing references to fieldsets to render
+*     them within vertical tabs.
+*   - storage: $form_state['storage'] is not a special key, and no specific
+*     support is provided for it in the Form API. By tradition it was
+*     the location where application-specific data was stored for communication
+*     between the submit, validation, and form builder functions, especially
+*     in a multi-step-style form. Form implementations may use any key(s)
+*     within $form_state (other than the keys listed here and other reserved
+*     ones used by Form API internals) for this kind of storage. The
+*     recommended way to ensure that the chosen key doesn't conflict with ones
+*     used by the Form API or other modules is to use the module name as the
+*     key name or a prefix for the key name. For example, the Node module uses
+*     $form_state['node'] in node editing forms to store information about the
+*     node being edited, and this information stays available across successive
+*     clicks of the "Preview" button as well as when the "Save" button is
+*     finally clicked.
+*   - buttons: A list containing copies of all submit and button elements in
+*     the form.
+*   - complete form: A reference to the $form variable containing the complete
+*     form structure. #process, #after_build, #element_validate, and other
+*     handlers being invoked on a form element may use this reference to access
+*     other information in the form the element is contained in.
+*   - temporary: An array holding temporary data accessible during the current
+*     page request only. All $form_state properties that are not reserved keys
+*     (see form_state_keys_no_cache()) persist throughout a multistep form
+*     sequence. Form API provides this key for modules to communicate
+*     information across form-related functions during a single page request.
+*     It may be used to temporarily save data that does not need to or should
+*     not be cached during the whole form workflow; e.g., data that needs to be
+*     accessed during the current form build process only. There is no use-case
+*     for this functionality in Drupal core.
+*   - wrapper_callback: Modules that wish to pre-populate certain forms with
+*     common elements, such as back/next/save buttons in multi-step form
+*     wizards, may define a form builder function name that returns a form
+*     structure, which is passed on to the actual form builder function.
+*     Such implementations may either define the 'wrapper_callback' via
+*     hook_forms() or have to invoke drupal_build_form() (instead of
+*     drupal_get_form()) on their own in a custom menu callback to prepare
+*     $form_state accordingly.
+*   Information on how certain $form_state properties control redirection
+*   behavior after form submission may be found in drupal_redirect_form().
+*
+* @return
+*   The rendered form. This function may also perform a redirect and hence may
+*   not return at all, depending upon the $form_state flags that were set.
+*
+* @see drupal_redirect_form()
+*/
+function drupal_build_form($form_id, &$form_state) {
+// Ensure some defaults; if already set they will not be overridden.
+$form_state += form_state_defaults();
+if (!isset($form_state['input'])) {
+$form_state['input'] = $form_state['method'] == 'get' ? $_GET : $_POST;
+}
+if (isset($_SESSION['batch_form_state'])) {
+// We've been redirected here after a batch processing. The form has
+// already been processed, but needs to be rebuilt. See _batch_finished().
+$form_state = $_SESSION['batch_form_state'];
+unset($_SESSION['batch_form_state']);
+return drupal_rebuild_form($form_id, $form_state);
+}
+// If the incoming input contains a form_build_id, we'll check the cache for a
+// copy of the form in question. If it's there, we don't have to rebuild the
+// form to proceed. In addition, if there is stored form_state data from a
+// previous step, we'll retrieve it so it can be passed on to the form
+// processing code.
+$check_cache = isset($form_state['input']['form_id']) && $form_state['input']['form_id'] == $form_id && !empty($form_state['input']['form_build_id']);
+if ($check_cache) {
+$form = form_get_cache($form_state['input']['form_build_id'], $form_state);
+}
+// If the previous bit of code didn't result in a populated $form object, we
+// are hitting the form for the first time and we need to build it from
+// scratch.
+if (!isset($form)) {
+// If we attempted to serve the form from cache, uncacheable $form_state
+// keys need to be removed after retrieving and preparing the form, except
+// any that were already set prior to retrieving the form.
+if ($check_cache) {
+$form_state_before_retrieval = $form_state;
+}
+$form = drupal_retrieve_form($form_id, $form_state);
+drupal_prepare_form($form_id, $form, $form_state);
+// form_set_cache() removes uncacheable $form_state keys defined in
+// form_state_keys_no_cache() in order for multi-step forms to work
+// properly. This means that form processing logic for single-step forms
+// using $form_state['cache'] may depend on data stored in those keys
+// during drupal_retrieve_form()/drupal_prepare_form(), but form
+// processing should not depend on whether the form is cached or not, so
+// $form_state is adjusted to match what it would be after a
+// form_set_cache()/form_get_cache() sequence. These exceptions are
+// allowed to survive here:
+// - always_process: Does not make sense in conjunction with form caching
+//   in the first place, since passing form_build_id as a GET parameter is
+//   not desired.
+// - temporary: Any assigned data is expected to survives within the same
+//   page request.
+if ($check_cache) {
+$uncacheable_keys = array_flip(array_diff(form_state_keys_no_cache(), array('always_process', 'temporary')));
+$form_state = array_diff_key($form_state, $uncacheable_keys);
+$form_state += $form_state_before_retrieval;
+}
+}
+// Now that we have a constructed form, process it. This is where:
+// - Element #process functions get called to further refine $form.
+// - User input, if any, gets incorporated in the #value property of the
+//   corresponding elements and into $form_state['values'].
+// - Validation and submission handlers are called.
+// - If this submission is part of a multistep workflow, the form is rebuilt
+//   to contain the information of the next step.
+// - If necessary, the form and form state are cached or re-cached, so that
+//   appropriate information persists to the next page request.
+// All of the handlers in the pipeline receive $form_state by reference and
+// can use it to know or update information about the state of the form.
+drupal_process_form($form_id, $form, $form_state);
+// If this was a successful submission of a single-step form or the last step
+// of a multi-step form, then drupal_process_form() issued a redirect to
+// another page, or back to this page, but as a new request. Therefore, if
+// we're here, it means that this is either a form being viewed initially
+// before any user input, or there was a validation error requiring the form
+// to be re-displayed, or we're in a multi-step workflow and need to display
+// the form's next step. In any case, we have what we need in $form, and can
+// return it for rendering.
+return $form;
+}
+/**
+* Retrieves default values for the $form_state array.
+*/
+function form_state_defaults() {
+return array(
+'rebuild' => FALSE,
+'rebuild_info' => array(),
+'redirect' => NULL,
+// @todo 'args' is usually set, so no other default 'build_info' keys are
+//   appended via += form_state_defaults().
+'build_info' => array(
+'args' => array(),
+'files' => array(),
+),
+'temporary' => array(),
+'submitted' => FALSE,
+'executed' => FALSE,
+'programmed' => FALSE,
+'programmed_bypass_access_check' => TRUE,
+'cache'=> FALSE,
+'method' => 'post',
+'groups' => array(),
+'buttons' => array(),
+);
+}
+/**
+* Constructs a new $form from the information in $form_state.
+*
+* This is the key function for making multi-step forms advance from step to
+* step. It is called by drupal_process_form() when all user input processing,
+* including calling validation and submission handlers, for the request is
+* finished. If a validate or submit handler set $form_state['rebuild'] to TRUE,
+* and if other conditions don't preempt a rebuild from happening, then this
+* function is called to generate a new $form, the next step in the form
+* workflow, to be returned for rendering.
+*
+* Ajax form submissions are almost always multi-step workflows, so that is one
+* common use-case during which form rebuilding occurs. See ajax_form_callback()
+* for more information about creating Ajax-enabled forms.
+*
+* @param $form_id
+*   The unique string identifying the desired form. If a function
+*   with that name exists, it is called to build the form array.
+*   Modules that need to generate the same form (or very similar forms)
+*   using different $form_ids can implement hook_forms(), which maps
+*   different $form_id values to the proper form constructor function. Examples
+*   may be found in node_forms() and search_forms().
+* @param $form_state
+*   A keyed array containing the current state of the form.
+* @param $old_form
+*   (optional) A previously built $form. Used to retain the #build_id and
+*   #action properties in Ajax callbacks and similar partial form rebuilds. The
+*   only properties copied from $old_form are the ones which both exist in
+*   $old_form and for which $form_state['rebuild_info']['copy'][PROPERTY] is
+*   TRUE. If $old_form is not passed, the entire $form is rebuilt freshly.
+*   'rebuild_info' needs to be a separate top-level property next to
+*   'build_info', since the contained data must not be cached.
+*
+* @return
+*   The newly built form.
+*
+* @see drupal_process_form()
+* @see ajax_form_callback()
+*/
+function drupal_rebuild_form($form_id, &$form_state, $old_form = NULL) {
+$form = drupal_retrieve_form($form_id, $form_state);
+// If only parts of the form will be returned to the browser (e.g., Ajax or
+// RIA clients), or if the form already had a new build ID regenerated when it
+// was retrieved from the form cache, reuse the existing #build_id.
+// Otherwise, a new #build_id is generated, to not clobber the previous
+// build's data in the form cache; also allowing the user to go back to an
+// earlier build, make changes, and re-submit.
+// @see drupal_prepare_form()
+$enforce_old_build_id = isset($old_form['#build_id']) && !empty($form_state['rebuild_info']['copy']['#build_id']);
+$old_form_is_mutable_copy = isset($old_form['#build_id_old']);
+if ($enforce_old_build_id || $old_form_is_mutable_copy) {
+$form['#build_id'] = $old_form['#build_id'];
+if ($old_form_is_mutable_copy) {
+$form['#build_id_old'] = $old_form['#build_id_old'];
+}
+}
+else {
+if (isset($old_form['#build_id'])) {
+$form['#build_id_old'] = $old_form['#build_id'];
+}
+$form['#build_id'] = 'form-' . drupal_random_key();
+}
+// #action defaults to request_uri(), but in case of Ajax and other partial
+// rebuilds, the form is submitted to an alternate URL, and the original
+// #action needs to be retained.
+if (isset($old_form['#action']) && !empty($form_state['rebuild_info']['copy']['#action'])) {
+$form['#action'] = $old_form['#action'];
+}
+drupal_prepare_form($form_id, $form, $form_state);
+// Caching is normally done in drupal_process_form(), but what needs to be
+// cached is the $form structure before it passes through form_builder(),
+// so we need to do it here.
+// @todo For Drupal 8, find a way to avoid this code duplication.
+if (empty($form_state['no_cache'])) {
+form_set_cache($form['#build_id'], $form, $form_state);
+}
+// Clear out all group associations as these might be different when
+// re-rendering the form.
+$form_state['groups'] = array();
+// Return a fully built form that is ready for rendering.
+return form_builder($form_id, $form, $form_state);
+}
+/**
+* Fetches a form from cache.
+*/
+function form_get_cache($form_build_id, &$form_state) {
+if ($cached = cache_get('form_' . $form_build_id, 'cache_form')) {
+$form = $cached->data;
+global $user;
+if ((isset($form['#cache_token']) && drupal_valid_token($form['#cache_token'])) || (!isset($form['#cache_token']) && !$user->uid)) {
+if ($cached = cache_get('form_state_' . $form_build_id, 'cache_form')) {
+// Re-populate $form_state for subsequent rebuilds.
+$form_state = $cached->data + $form_state;
+// If the original form is contained in include files, load the files.
+// @see form_load_include()
+$form_state['build_info'] += array('files' => array());
+foreach ($form_state['build_info']['files'] as $file) {
+if (is_array($file)) {
+$file += array('type' => 'inc', 'name' => $file['module']);
+module_load_include($file['type'], $file['module'], $file['name']);
+}
+elseif (file_exists($file)) {
+require_once DRUPAL_ROOT . '/' . $file;
+}
+}
+}
+// Generate a new #build_id if the cached form was rendered on a cacheable
+// page.
+if (!empty($form_state['build_info']['immutable'])) {
+$form['#build_id_old'] = $form['#build_id'];
+$form['#build_id'] = 'form-' . drupal_random_key();
+$form['form_build_id']['#value'] = $form['#build_id'];
+$form['form_build_id']['#id'] = $form['#build_id'];
+unset($form_state['build_info']['immutable']);
+}
+return $form;
+}
+}
+}
+/**
+* Stores a form in the cache.
+*/
+function form_set_cache($form_build_id, $form, $form_state) {
+// 6 hours cache life time for forms should be plenty.
+$expire = 21600;
+// Ensure that the form build_id embedded in the form structure is the same as
+// the one passed in as a parameter. This is an additional safety measure to
+// prevent legacy code operating directly with form_get_cache and
+// form_set_cache from accidentally overwriting immutable form state.
+if ($form['#build_id'] != $form_build_id) {
+watchdog('form', 'Form build-id mismatch detected while attempting to store a form in the cache.', array(), WATCHDOG_ERROR);
+return;
+}
+// Cache form structure.
+if (isset($form)) {
+if ($GLOBALS['user']->uid) {
+$form['#cache_token'] = drupal_get_token();
+}
+unset($form['#build_id_old']);
+cache_set('form_' . $form_build_id, $form, 'cache_form', REQUEST_TIME + $expire);
+}
+// Cache form state.
+if (variable_get('cache', 0) && drupal_page_is_cacheable()) {
+$form_state['build_info']['immutable'] = TRUE;
+}
+if ($data = array_diff_key($form_state, array_flip(form_state_keys_no_cache()))) {
+cache_set('form_state_' . $form_build_id, $data, 'cache_form', REQUEST_TIME + $expire);
+}
+}
+/**
+* Returns an array of $form_state keys that shouldn't be cached.
+*/
+function form_state_keys_no_cache() {
+return array(
+// Public properties defined by form constructors and form handlers.
+'always_process',
+'must_validate',
+'rebuild',
+'rebuild_info',
+'redirect',
+'no_redirect',
+'temporary',
+// Internal properties defined by form processing.
+'buttons',
+'triggering_element',
+'clicked_button',
+'complete form',
+'groups',
+'input',
+'method',
+'submit_handlers',
+'submitted',
+'executed',
+'validate_handlers',
+'values',
+);
+}
+/**
+* Ensures an include file is loaded whenever the form is processed.
+*
+* Example:
+* @code
+*   // Load node.admin.inc from Node module.
+*   form_load_include($form_state, 'inc', 'node', 'node.admin');
+* @endcode
+*
+* Use this function instead of module_load_include() from inside a form
+* constructor or any form processing logic as it ensures that the include file
+* is loaded whenever the form is processed. In contrast to using
+* module_load_include() directly, form_load_include() makes sure the include
+* file is correctly loaded also if the form is cached.
+*
+* @param $form_state
+*   The current state of the form.
+* @param $type
+*   The include file's type (file extension).
+* @param $module
+*   The module to which the include file belongs.
+* @param $name
+*   (optional) The base file name (without the $type extension). If omitted,
+*   $module is used; i.e., resulting in "$module.$type" by default.
+*
+* @return
+*   The filepath of the loaded include file, or FALSE if the include file was
+*   not found or has been loaded already.
+*
+* @see module_load_include()
+*/
+function form_load_include(&$form_state, $type, $module, $name = NULL) {
+if (!isset($name)) {
+$name = $module;
+}
+if (!isset($form_state['build_info']['files']["$module:$name.$type"])) {
+// Only add successfully included files to the form state.
+if ($result = module_load_include($type, $module, $name)) {
+$form_state['build_info']['files']["$module:$name.$type"] = array(
+'type' => $type,
+'module' => $module,
+'name' => $name,
+);
+return $result;
+}
+}
+return FALSE;
+}
+/**
+* Retrieves, populates, and processes a form.
+*
+* This function allows you to supply values for form elements and submit a
+* form for processing. Compare to drupal_get_form(), which also builds and
+* processes a form, but does not allow you to supply values.
+*
+* There is no return value, but you can check to see if there are errors
+* by calling form_get_errors().
+*
+* @param $form_id
+*   The unique string identifying the desired form. If a function
+*   with that name exists, it is called to build the form array.
+*   Modules that need to generate the same form (or very similar forms)
+*   using different $form_ids can implement hook_forms(), which maps
+*   different $form_id values to the proper form constructor function. Examples
+*   may be found in node_forms() and search_forms().
+* @param $form_state
+*   A keyed array containing the current state of the form. Most important is
+*   the $form_state['values'] collection, a tree of data used to simulate the
+*   incoming $_POST information from a user's form submission. If a key is not
+*   filled in $form_state['values'], then the default value of the respective
+*   element is used. To submit an unchecked checkbox or other control that
+*   browsers submit by not having a $_POST entry, include the key, but set the
+*   value to NULL.
+* @param ...
+*   Any additional arguments are passed on to the functions called by
+*   drupal_form_submit(), including the unique form constructor function.
+*   For example, the node_edit form requires that a node object be passed
+*   in here when it is called. Arguments that need to be passed by reference
+*   should not be included here, but rather placed directly in the $form_state
+*   build info array so that the reference can be preserved. For example, a
+*   form builder function with the following signature:
+*   @code
+*   function mymodule_form($form, &$form_state, &$object) {
+*   }
+*   @endcode
+*   would be called via drupal_form_submit() as follows:
+*   @code
+*   $form_state['values'] = $my_form_values;
+*   $form_state['build_info']['args'] = array(&$object);
+*   drupal_form_submit('mymodule_form', $form_state);
+*   @endcode
+* For example:
+* @code
+* // register a new user
+* $form_state = array();
+* $form_state['values']['name'] = 'robo-user';
+* $form_state['values']['mail'] = 'robouser@example.com';
+* $form_state['values']['pass']['pass1'] = 'password';
+* $form_state['values']['pass']['pass2'] = 'password';
+* $form_state['values']['op'] = t('Create new account');
+* drupal_form_submit('user_register_form', $form_state);
+* @endcode
+*/
+function drupal_form_submit($form_id, &$form_state) {
+if (!isset($form_state['build_info']['args'])) {
+$args = func_get_args();
+array_shift($args);
+array_shift($args);
+$form_state['build_info']['args'] = $args;
+}
+// Merge in default values.
+$form_state += form_state_defaults();
+// Populate $form_state['input'] with the submitted values before retrieving
+// the form, to be consistent with what drupal_build_form() does for
+// non-programmatic submissions (form builder functions may expect it to be
+// there).
+$form_state['input'] = $form_state['values'];
+$form_state['programmed'] = TRUE;
+$form = drupal_retrieve_form($form_id, $form_state);
+// Programmed forms are always submitted.
+$form_state['submitted'] = TRUE;
+// Reset form validation.
+$form_state['must_validate'] = TRUE;
+form_clear_error();
+drupal_prepare_form($form_id, $form, $form_state);
+drupal_process_form($form_id, $form, $form_state);
+}
+/**
+* Retrieves the structured array that defines a given form.
+*
+* @param $form_id
+*   The unique string identifying the desired form. If a function
+*   with that name exists, it is called to build the form array.
+*   Modules that need to generate the same form (or very similar forms)
+*   using different $form_ids can implement hook_forms(), which maps
+*   different $form_id values to the proper form constructor function.
+* @param $form_state
+*   A keyed array containing the current state of the form, including the
+*   additional arguments to drupal_get_form() or drupal_form_submit() in the
+*   'args' component of the array.
+*/
+function drupal_retrieve_form($form_id, &$form_state) {
+$forms = &drupal_static(__FUNCTION__);
+// Record the $form_id.
+$form_state['build_info']['form_id'] = $form_id;
+// Record the filepath of the include file containing the original form, so
+// the form builder callbacks can be loaded when the form is being rebuilt
+// from cache on a different path (such as 'system/ajax'). See
+// form_get_cache(). Don't do this in maintenance mode as Drupal may not be
+// fully bootstrapped (i.e. during installation) in which case
+// menu_get_item() is not available.
+if (!isset($form_state['build_info']['files']['menu']) && !defined('MAINTENANCE_MODE')) {
+$item = menu_get_item();
+if (!empty($item['include_file'])) {
+// Do not use form_load_include() here, as the file is already loaded.
+// Anyway, form_get_cache() is able to handle filepaths too.
+$form_state['build_info']['files']['menu'] = $item['include_file'];
+}
+}
+// We save two copies of the incoming arguments: one for modules to use
+// when mapping form ids to constructor functions, and another to pass to
+// the constructor function itself.
+$args = $form_state['build_info']['args'];
+// We first check to see if there's a function named after the $form_id.
+// If there is, we simply pass the arguments on to it to get the form.
+if (!function_exists($form_id)) {
+// In cases where many form_ids need to share a central constructor function,
+// such as the node editing form, modules can implement hook_forms(). It
+// maps one or more form_ids to the correct constructor functions.
+//
+// We cache the results of that hook to save time, but that only works
+// for modules that know all their form_ids in advance. (A module that
+// adds a small 'rate this comment' form to each comment in a list
+// would need a unique form_id for each one, for example.)
+//
+// So, we call the hook if $forms isn't yet populated, OR if it doesn't
+// yet have an entry for the requested form_id.
+if (!isset($forms) || !isset($forms[$form_id])) {
+$forms = module_invoke_all('forms', $form_id, $args);
+}
+$form_definition = $forms[$form_id];
+if (isset($form_definition['callback arguments'])) {
+$args = array_merge($form_definition['callback arguments'], $args);
+}
+if (isset($form_definition['callback'])) {
+$callback = $form_definition['callback'];
+$form_state['build_info']['base_form_id'] = isset($form_definition['base_form_id']) ? $form_definition['base_form_id'] : $callback;
+}
+// In case $form_state['wrapper_callback'] is not defined already, we also
+// allow hook_forms() to define one.
+if (!isset($form_state['wrapper_callback']) && isset($form_definition['wrapper_callback'])) {
+$form_state['wrapper_callback'] = $form_definition['wrapper_callback'];
+}
+}
+$form = array();
+// We need to pass $form_state by reference in order for forms to modify it,
+// since call_user_func_array() requires that referenced variables are passed
+// explicitly.
+$args = array_merge(array($form, &$form_state), $args);
+// When the passed $form_state (not using drupal_get_form()) defines a
+// 'wrapper_callback', then it requests to invoke a separate (wrapping) form
+// builder function to pre-populate the $form array with form elements, which
+// the actual form builder function ($callback) expects. This allows for
+// pre-populating a form with common elements for certain forms, such as
+// back/next/save buttons in multi-step form wizards. See drupal_build_form().
+if (isset($form_state['wrapper_callback']) && is_callable($form_state['wrapper_callback'])) {
+$form = call_user_func_array($form_state['wrapper_callback'], $args);
+// Put the prepopulated $form into $args.
+$args[0] = $form;
+}
+// If $callback was returned by a hook_forms() implementation, call it.
+// Otherwise, call the function named after the form id.
+$form = call_user_func_array(isset($callback) ? $callback : $form_id, $args);
+$form['#form_id'] = $form_id;
+return $form;
+}
+/**
+* Processes a form submission.
+*
+* This function is the heart of form API. The form gets built, validated and in
+* appropriate cases, submitted and rebuilt.
+*
+* @param $form_id
+*   The unique string identifying the current form.
+* @param $form
+*   An associative array containing the structure of the form.
+* @param $form_state
+*   A keyed array containing the current state of the form. This
+*   includes the current persistent storage data for the form, and
+*   any data passed along by earlier steps when displaying a
+*   multi-step form. Additional information, like the sanitized $_POST
+*   data, is also accumulated here.
+*/
+function drupal_process_form($form_id, &$form, &$form_state) {
+$form_state['values'] = array();
+// With $_GET, these forms are always submitted if requested.
+if ($form_state['method'] == 'get' && !empty($form_state['always_process'])) {
+if (!isset($form_state['input']['form_build_id'])) {
+$form_state['input']['form_build_id'] = $form['#build_id'];
+}
+if (!isset($form_state['input']['form_id'])) {
+$form_state['input']['form_id'] = $form_id;
+}
+if (!isset($form_state['input']['form_token']) && isset($form['#token'])) {
+$form_state['input']['form_token'] = drupal_get_token($form['#token']);
+}
+}
+// form_builder() finishes building the form by calling element #process
+// functions and mapping user input, if any, to #value properties, and also
+// storing the values in $form_state['values']. We need to retain the
+// unprocessed $form in case it needs to be cached.
+$unprocessed_form = $form;
+$form = form_builder($form_id, $form, $form_state);
+// Only process the input if we have a correct form submission.
+if ($form_state['process_input']) {
+drupal_validate_form($form_id, $form, $form_state);
+// drupal_html_id() maintains a cache of element IDs it has seen,
+// so it can prevent duplicates. We want to be sure we reset that
+// cache when a form is processed, so scenarios that result in
+// the form being built behind the scenes and again for the
+// browser don't increment all the element IDs needlessly.
+if (!form_get_errors()) {
+// In case of errors, do not break HTML IDs of other forms.
+drupal_static_reset('drupal_html_id');
+}
+if ($form_state['submitted'] && !form_get_errors() && !$form_state['rebuild']) {
+// Execute form submit handlers.
+form_execute_handlers('submit', $form, $form_state);
+// We'll clear out the cached copies of the form and its stored data
+// here, as we've finished with them. The in-memory copies are still
+// here, though.
+if (!variable_get('cache', 0) && !empty($form_state['values']['form_build_id'])) {
+cache_clear_all('form_' . $form_state['values']['form_build_id'], 'cache_form');
+cache_clear_all('form_state_' . $form_state['values']['form_build_id'], 'cache_form');
+}
+// If batches were set in the submit handlers, we process them now,
+// possibly ending execution. We make sure we do not react to the batch
+// that is already being processed (if a batch operation performs a
+// drupal_form_submit).
+if ($batch =& batch_get() && !isset($batch['current_set'])) {
+// Store $form_state information in the batch definition.
+// We need the full $form_state when either:
+// - Some submit handlers were saved to be called during batch
+//   processing. See form_execute_handlers().
+// - The form is multistep.
+// In other cases, we only need the information expected by
+// drupal_redirect_form().
+if ($batch['has_form_submits'] || !empty($form_state['rebuild'])) {
+$batch['form_state'] = $form_state;
+}
+else {
+$batch['form_state'] = array_intersect_key($form_state, array_flip(array('programmed', 'rebuild', 'storage', 'no_redirect', 'redirect')));
+}
+$batch['progressive'] = !$form_state['programmed'];
+batch_process();
+// Execution continues only for programmatic forms.
+// For 'regular' forms, we get redirected to the batch processing
+// page. Form redirection will be handled in _batch_finished(),
+// after the batch is processed.
+}
+// Set a flag to indicate that the form has been processed and executed.
+$form_state['executed'] = TRUE;
+// Redirect the form based on values in $form_state.
+drupal_redirect_form($form_state);
+}
+// Don't rebuild or cache form submissions invoked via drupal_form_submit().
+if (!empty($form_state['programmed'])) {
+return;
+}
+// If $form_state['rebuild'] has been set and input has been processed
+// without validation errors, we are in a multi-step workflow that is not
+// yet complete. A new $form needs to be constructed based on the changes
+// made to $form_state during this request. Normally, a submit handler sets
+// $form_state['rebuild'] if a fully executed form requires another step.
+// However, for forms that have not been fully executed (e.g., Ajax
+// submissions triggered by non-buttons), there is no submit handler to set
+// $form_state['rebuild']. It would not make sense to redisplay the
+// identical form without an error for the user to correct, so we also
+// rebuild error-free non-executed forms, regardless of
+// $form_state['rebuild'].
+// @todo D8: Simplify this logic; considering Ajax and non-HTML front-ends,
+//   along with element-level #submit properties, it makes no sense to have
+//   divergent form execution based on whether the triggering element has
+//   #executes_submit_callback set to TRUE.
+if (($form_state['rebuild'] || !$form_state['executed']) && !form_get_errors()) {
+// Form building functions (e.g., _form_builder_handle_input_element())
+// may use $form_state['rebuild'] to determine if they are running in the
+// context of a rebuild, so ensure it is set.
+$form_state['rebuild'] = TRUE;
+$form = drupal_rebuild_form($form_id, $form_state, $form);
+}
+}
+// After processing the form, the form builder or a #process callback may
+// have set $form_state['cache'] to indicate that the form and form state
+// shall be cached. But the form may only be cached if the 'no_cache' property
+// is not set to TRUE. Only cache $form as it was prior to form_builder(),
+// because form_builder() must run for each request to accommodate new user
+// input. Rebuilt forms are not cached here, because drupal_rebuild_form()
+// already takes care of that.
+if (!$form_state['rebuild'] && $form_state['cache'] && empty($form_state['no_cache'])) {
+form_set_cache($form['#build_id'], $unprocessed_form, $form_state);
+}
+}
+/**
+* Prepares a structured form array.
+*
+* Adds required elements, executes any hook_form_alter functions, and
+* optionally inserts a validation token to prevent tampering.
+*
+* @param $form_id
+*   A unique string identifying the form for validation, submission,
+*   theming, and hook_form_alter functions.
+* @param $form
+*   An associative array containing the structure of the form.
+* @param $form_state
+*   A keyed array containing the current state of the form. Passed
+*   in here so that hook_form_alter() calls can use it, as well.
+*/
+function drupal_prepare_form($form_id, &$form, &$form_state) {
+global $user;
+$form['#type'] = 'form';
+$form_state['programmed'] = isset($form_state['programmed']) ? $form_state['programmed'] : FALSE;
+// Fix the form method, if it is 'get' in $form_state, but not in $form.
+if ($form_state['method'] == 'get' && !isset($form['#method'])) {
+$form['#method'] = 'get';
+}
+// Generate a new #build_id for this form, if none has been set already. The
+// form_build_id is used as key to cache a particular build of the form. For
+// multi-step forms, this allows the user to go back to an earlier build, make
+// changes, and re-submit.
+// @see drupal_build_form()
+// @see drupal_rebuild_form()
+if (!isset($form['#build_id'])) {
+$form['#build_id'] = 'form-' . drupal_random_key();
+}
+$form['form_build_id'] = array(
+'#type' => 'hidden',
+'#value' => $form['#build_id'],
+'#id' => $form['#build_id'],
+'#name' => 'form_build_id',
+// Form processing and validation requires this value, so ensure the
+// submitted form value appears literally, regardless of custom #tree
+// and #parents being set elsewhere.
+'#parents' => array('form_build_id'),
+);
+// Add a token, based on either #token or form_id, to any form displayed to
+// authenticated users. This ensures that any submitted form was actually
+// requested previously by the user and protects against cross site request
+// forgeries.
+// This does not apply to programmatically submitted forms. Furthermore, since
+// tokens are session-bound and forms displayed to anonymous users are very
+// likely cached, we cannot assign a token for them.
+// During installation, there is no $user yet.
+if (!empty($user->uid) && !$form_state['programmed']) {
+// Form constructors may explicitly set #token to FALSE when cross site
+// request forgery is irrelevant to the form, such as search forms.
+if (isset($form['#token']) && $form['#token'] === FALSE) {
+unset($form['#token']);
+}
+// Otherwise, generate a public token based on the form id.
+else {
+$form['#token'] = $form_id;
+$form['form_token'] = array(
+'#id' => drupal_html_id('edit-' . $form_id . '-form-token'),
+'#type' => 'token',
+'#default_value' => drupal_get_token($form['#token']),
+// Form processing and validation requires this value, so ensure the
+// submitted form value appears literally, regardless of custom #tree
+// and #parents being set elsewhere.
+'#parents' => array('form_token'),
+);
+}
+}
+if (isset($form_id)) {
+$form['form_id'] = array(
+'#type' => 'hidden',
+'#value' => $form_id,
+'#id' => drupal_html_id("edit-$form_id"),
+// Form processing and validation requires this value, so ensure the
+// submitted form value appears literally, regardless of custom #tree
+// and #parents being set elsewhere.
+'#parents' => array('form_id'),
+);
+}
+if (!isset($form['#id'])) {
+$form['#id'] = drupal_html_id($form_id);
+}
+$form += element_info('form');
+$form += array('#tree' => FALSE, '#parents' => array());
+if (!isset($form['#validate'])) {
+// Ensure that modules can rely on #validate being set.
+$form['#validate'] = array();
+// Check for a handler specific to $form_id.
+if (function_exists($form_id . '_validate')) {
+$form['#validate'][] = $form_id . '_validate';
+}
+// Otherwise check whether this is a shared form and whether there is a
+// handler for the shared $form_id.
+elseif (isset($form_state['build_info']['base_form_id']) && function_exists($form_state['build_info']['base_form_id'] . '_validate')) {
+$form['#validate'][] = $form_state['build_info']['base_form_id'] . '_validate';
+}
+}
+if (!isset($form['#submit'])) {
+// Ensure that modules can rely on #submit being set.
+$form['#submit'] = array();
+// Check for a handler specific to $form_id.
+if (function_exists($form_id . '_submit')) {
+$form['#submit'][] = $form_id . '_submit';
+}
+// Otherwise check whether this is a shared form and whether there is a
+// handler for the shared $form_id.
+elseif (isset($form_state['build_info']['base_form_id']) && function_exists($form_state['build_info']['base_form_id'] . '_submit')) {
+$form['#submit'][] = $form_state['build_info']['base_form_id'] . '_submit';
+}
+}
+// If no #theme has been set, automatically apply theme suggestions.
+// theme_form() itself is in #theme_wrappers and not #theme. Therefore, the
+// #theme function only has to care for rendering the inner form elements,
+// not the form itself.
+if (!isset($form['#theme'])) {
+$form['#theme'] = array($form_id);
+if (isset($form_state['build_info']['base_form_id'])) {
+$form['#theme'][] = $form_state['build_info']['base_form_id'];
+}
+}
+// Invoke hook_form_alter(), hook_form_BASE_FORM_ID_alter(), and
+// hook_form_FORM_ID_alter() implementations.
+$hooks = array('form');
+if (isset($form_state['build_info']['base_form_id'])) {
+$hooks[] = 'form_' . $form_state['build_info']['base_form_id'];
+}
+$hooks[] = 'form_' . $form_id;
+drupal_alter($hooks, $form, $form_state, $form_id);
+}
+/**
+* Helper function to call form_set_error() if there is a token error.
+*/
+function _drupal_invalid_token_set_form_error() {
+$path = current_path();
+$query = drupal_get_query_parameters();
+$url = url($path, array('query' => $query));
+// Setting this error will cause the form to fail validation.
+form_set_error('form_token', t('The form has become outdated. Copy any unsaved work in the form below and then <a href="@link">reload this page</a>.', array('@link' => $url)));
+}
+/**
+* Validates user-submitted form data in the $form_state array.
+*
+* @param $form_id
+*   A unique string identifying the form for validation, submission,
+*   theming, and hook_form_alter functions.
+* @param $form
+*   An associative array containing the structure of the form, which is passed
+*   by reference. Form validation handlers are able to alter the form structure
+*   (like #process and #after_build callbacks during form building) in case of
+*   a validation error. If a validation handler alters the form structure, it
+*   is responsible for validating the values of changed form elements in
+*   $form_state['values'] to prevent form submit handlers from receiving
+*   unvalidated values.
+* @param $form_state
+*   A keyed array containing the current state of the form. The current
+*   user-submitted data is stored in $form_state['values'], though
+*   form validation functions are passed an explicit copy of the
+*   values for the sake of simplicity. Validation handlers can also use
+*   $form_state to pass information on to submit handlers. For example:
+*     $form_state['data_for_submission'] = $data;
+*   This technique is useful when validation requires file parsing,
+*   web service requests, or other expensive requests that should
+*   not be repeated in the submission step.
+*/
+function drupal_validate_form($form_id, &$form, &$form_state) {
+$validated_forms = &drupal_static(__FUNCTION__, array());
+if (isset($validated_forms[$form_id]) && empty($form_state['must_validate'])) {
+return;
+}
+// If the session token was set by drupal_prepare_form(), ensure that it
+// matches the current user's session. This is duplicate to code in
+// form_builder() but left to protect any custom form handling code.
+if (!empty($form['#token'])) {
+if (!drupal_valid_token($form_state['values']['form_token'], $form['#token']) || !empty($form_state['invalid_token'])) {
+_drupal_invalid_token_set_form_error();
+// Stop here and don't run any further validation handlers, because they
+// could invoke non-safe operations which opens the door for CSRF
+// vulnerabilities.
+$validated_forms[$form_id] = TRUE;
+return;
+}
+}
+_form_validate($form, $form_state, $form_id);
+$validated_forms[$form_id] = TRUE;
+// If validation errors are limited then remove any non validated form values,
+// so that only values that passed validation are left for submit callbacks.
+if (isset($form_state['triggering_element']['#limit_validation_errors']) && $form_state['triggering_element']['#limit_validation_errors'] !== FALSE) {
+$values = array();
+foreach ($form_state['triggering_element']['#limit_validation_errors'] as $section) {
+// If the section exists within $form_state['values'], even if the value
+// is NULL, copy it to $values.
+$section_exists = NULL;
+$value = drupal_array_get_nested_value($form_state['values'], $section, $section_exists);
+if ($section_exists) {
+drupal_array_set_nested_value($values, $section, $value);
+}
+}
+// A button's #value does not require validation, so for convenience we
+// allow the value of the clicked button to be retained in its normal
+// $form_state['values'] locations, even if these locations are not included
+// in #limit_validation_errors.
+if (isset($form_state['triggering_element']['#button_type'])) {
+$button_value = $form_state['triggering_element']['#value'];
+// Like all input controls, the button value may be in the location
+// dictated by #parents. If it is, copy it to $values, but do not override
+// what may already be in $values.
+$parents = $form_state['triggering_element']['#parents'];
+if (!drupal_array_nested_key_exists($values, $parents) && drupal_array_get_nested_value($form_state['values'], $parents) === $button_value) {
+drupal_array_set_nested_value($values, $parents, $button_value);
+}
+// Additionally, form_builder() places the button value in
+// $form_state['values'][BUTTON_NAME]. If it's still there, after
+// validation handlers have run, copy it to $values, but do not override
+// what may already be in $values.
+$name = $form_state['triggering_element']['#name'];
+if (!isset($values[$name]) && isset($form_state['values'][$name]) && $form_state['values'][$name] === $button_value) {
+$values[$name] = $button_value;
+}
+}
+$form_state['values'] = $values;
+}
+}
+/**
+* Redirects the user to a URL after a form has been processed.
+*
+* After a form is submitted and processed, normally the user should be
+* redirected to a new destination page. This function figures out what that
+* destination should be, based on the $form_state array and the 'destination'
+* query string in the request URL, and redirects the user there.
+*
+* Usually (for exceptions, see below) $form_state['redirect'] determines where
+* to redirect the user. This can be set either to a string (the path to
+* redirect to), or an array of arguments for drupal_goto(). If
+* $form_state['redirect'] is missing, the user is usually (again, see below for
+* exceptions) redirected back to the page they came from, where they should see
+* a fresh, unpopulated copy of the form.
+*
+* Here is an example of how to set up a form to redirect to the path 'node':
+* @code
+* $form_state['redirect'] = 'node';
+* @endcode
+* And here is an example of how to redirect to 'node/123?foo=bar#baz':
+* @code
+* $form_state['redirect'] = array(
+*   'node/123',
+*   array(
+*     'query' => array(
+*       'foo' => 'bar',
+*     ),
+*     'fragment' => 'baz',
+*   ),
+* );
+* @endcode
+*
+* There are several exceptions to the "usual" behavior described above:
+* - If $form_state['programmed'] is TRUE, the form submission was usually
+*   invoked via drupal_form_submit(), so any redirection would break the script
+*   that invoked drupal_form_submit() and no redirection is done.
+* - If $form_state['rebuild'] is TRUE, the form is being rebuilt, and no
+*   redirection is done.
+* - If $form_state['no_redirect'] is TRUE, redirection is disabled. This is
+*   set, for instance, by ajax_get_form() to prevent redirection in Ajax
+*   callbacks. $form_state['no_redirect'] should never be set or altered by
+*   form builder functions or form validation/submit handlers.
+* - If $form_state['redirect'] is set to FALSE, redirection is disabled.
+* - If none of the above conditions has prevented redirection, then the
+*   redirect is accomplished by calling drupal_goto(), passing in the value of
+*   $form_state['redirect'] if it is set, or the current path if it is
+*   not. drupal_goto() preferentially uses the value of $_GET['destination']
+*   (the 'destination' URL query string) if it is present, so this will
+*   override any values set by $form_state['redirect']. Note that during
+*   installation, install_goto() is called in place of drupal_goto().
+*
+* @param $form_state
+*   An associative array containing the current state of the form.
+*
+* @see drupal_process_form()
+* @see drupal_build_form()
+*/
+function drupal_redirect_form($form_state) {
+// Skip redirection for form submissions invoked via drupal_form_submit().
+if (!empty($form_state['programmed'])) {
+return;
+}
+// Skip redirection if rebuild is activated.
+if (!empty($form_state['rebuild'])) {
+return;
+}
+// Skip redirection if it was explicitly disallowed.
+if (!empty($form_state['no_redirect'])) {
+return;
+}
+// Only invoke drupal_goto() if redirect value was not set to FALSE.
+if (!isset($form_state['redirect']) || $form_state['redirect'] !== FALSE) {
+if (isset($form_state['redirect'])) {
+if (is_array($form_state['redirect'])) {
+call_user_func_array('drupal_goto', $form_state['redirect']);
+}
+else {
+// This function can be called from the installer, which guarantees
+// that $redirect will always be a string, so catch that case here
+// and use the appropriate redirect function.
+$function = drupal_installation_attempted() ? 'install_goto' : 'drupal_goto';
+$function($form_state['redirect']);
+}
+}
+drupal_goto(current_path(), array('query' => drupal_get_query_parameters()));
+}
+}
+/**
+* Performs validation on form elements.
+*
+* First ensures required fields are completed, #maxlength is not exceeded, and
+* selected options were in the list of options given to the user. Then calls
+* user-defined validators.
+*
+* @param $elements
+*   An associative array containing the structure of the form.
+* @param $form_state
+*   A keyed array containing the current state of the form. The current
+*   user-submitted data is stored in $form_state['values'], though
+*   form validation functions are passed an explicit copy of the
+*   values for the sake of simplicity. Validation handlers can also
+*   $form_state to pass information on to submit handlers. For example:
+*     $form_state['data_for_submission'] = $data;
+*   This technique is useful when validation requires file parsing,
+*   web service requests, or other expensive requests that should
+*   not be repeated in the submission step.
+* @param $form_id
+*   A unique string identifying the form for validation, submission,
+*   theming, and hook_form_alter functions.
+*/
+function _form_validate(&$elements, &$form_state, $form_id = NULL) {
+// Also used in the installer, pre-database setup.
+$t = get_t();
+// Recurse through all children.
+foreach (element_children($elements) as $key) {
+if (isset($elements[$key]) && $elements[$key]) {
+_form_validate($elements[$key], $form_state);
+}
+}
+// Validate the current input.
+if (!isset($elements['#validated']) || !$elements['#validated']) {
+// The following errors are always shown.
+if (isset($elements['#needs_validation'])) {
+// Verify that the value is not longer than #maxlength.
+if (isset($elements['#maxlength']) && drupal_strlen($elements['#value']) > $elements['#maxlength']) {
+form_error($elements, $t('!name cannot be longer than %max characters but is currently %length characters long.', array('!name' => empty($elements['#title']) ? $elements['#parents'][0] : $elements['#title'], '%max' => $elements['#maxlength'], '%length' => drupal_strlen($elements['#value']))));
+}
+if (isset($elements['#options']) && isset($elements['#value'])) {
+if ($elements['#type'] == 'select') {
+$options = form_options_flatten($elements['#options']);
+}
+else {
+$options = $elements['#options'];
+}
+if (is_array($elements['#value'])) {
+$value = in_array($elements['#type'], array('checkboxes', 'tableselect')) ? array_keys($elements['#value']) : $elements['#value'];
+foreach ($value as $v) {
+if (!isset($options[$v])) {
+form_error($elements, $t('An illegal choice has been detected. Please contact the site administrator.'));
+watchdog('form', 'Illegal choice %choice in !name element.', array('%choice' => $v, '!name' => empty($elements['#title']) ? $elements['#parents'][0] : $elements['#title']), WATCHDOG_ERROR);
+}
+}
+}
+// Non-multiple select fields always have a value in HTML. If the user
+// does not change the form, it will be the value of the first option.
+// Because of this, form validation for the field will almost always
+// pass, even if the user did not select anything. To work around this
+// browser behavior, required select fields without a #default_value get
+// an additional, first empty option. In case the submitted value is
+// identical to the empty option's value, we reset the element's value
+// to NULL to trigger the regular #required handling below.
+// @see form_process_select()
+elseif ($elements['#type'] == 'select' && !$elements['#multiple'] && $elements['#required'] && !isset($elements['#default_value']) && $elements['#value'] === $elements['#empty_value']) {
+$elements['#value'] = NULL;
+form_set_value($elements, NULL, $form_state);
+}
+elseif (!isset($options[$elements['#value']])) {
+form_error($elements, $t('An illegal choice has been detected. Please contact the site administrator.'));
+watchdog('form', 'Illegal choice %choice in %name element.', array('%choice' => $elements['#value'], '%name' => empty($elements['#title']) ? $elements['#parents'][0] : $elements['#title']), WATCHDOG_ERROR);
+}
+}
+}
+// While this element is being validated, it may be desired that some calls
+// to form_set_error() be suppressed and not result in a form error, so
+// that a button that implements low-risk functionality (such as "Previous"
+// or "Add more") that doesn't require all user input to be valid can still
+// have its submit handlers triggered. The triggering element's
+// #limit_validation_errors property contains the information for which
+// errors are needed, and all other errors are to be suppressed. The
+// #limit_validation_errors property is ignored if submit handlers will run,
+// but the element doesn't have a #submit property, because it's too large a
+// security risk to have any invalid user input when executing form-level
+// submit handlers.
+if (isset($form_state['triggering_element']['#limit_validation_errors']) && ($form_state['triggering_element']['#limit_validation_errors'] !== FALSE) && !($form_state['submitted'] && !isset($form_state['triggering_element']['#submit']))) {
+form_set_error(NULL, '', $form_state['triggering_element']['#limit_validation_errors']);
+}
+// If submit handlers won't run (due to the submission having been triggered
+// by an element whose #executes_submit_callback property isn't TRUE), then
+// it's safe to suppress all validation errors, and we do so by default,
+// which is particularly useful during an Ajax submission triggered by a
+// non-button. An element can override this default by setting the
+// #limit_validation_errors property. For button element types,
+// #limit_validation_errors defaults to FALSE (via system_element_info()),
+// so that full validation is their default behavior.
+elseif (isset($form_state['triggering_element']) && !isset($form_state['triggering_element']['#limit_validation_errors']) && !$form_state['submitted']) {
+form_set_error(NULL, '', array());
+}
+// As an extra security measure, explicitly turn off error suppression if
+// one of the above conditions wasn't met. Since this is also done at the
+// end of this function, doing it here is only to handle the rare edge case
+// where a validate handler invokes form processing of another form.
+else {
+drupal_static_reset('form_set_error:limit_validation_errors');
+}
+// Make sure a value is passed when the field is required.
+if (isset($elements['#needs_validation']) && $elements['#required']) {
+// A simple call to empty() will not cut it here as some fields, like
+// checkboxes, can return a valid value of '0'. Instead, check the
+// length if it's a string, and the item count if it's an array.
+// An unchecked checkbox has a #value of integer 0, different than string
+// '0', which could be a valid value.
+$is_empty_multiple = (!count($elements['#value']));
+$is_empty_string = (is_string($elements['#value']) && drupal_strlen(trim($elements['#value'])) == 0);
+$is_empty_value = ($elements['#value'] === 0);
+if ($is_empty_multiple || $is_empty_string || $is_empty_value) {
+// Although discouraged, a #title is not mandatory for form elements. In
+// case there is no #title, we cannot set a form error message.
+// Instead of setting no #title, form constructors are encouraged to set
+// #title_display to 'invisible' to improve accessibility.
+if (isset($elements['#title'])) {
+form_error($elements, $t('!name field is required.', array('!name' => $elements['#title'])));
+}
+else {
+form_error($elements);
+}
+}
+}
+// Call user-defined form level validators.
+if (isset($form_id)) {
+form_execute_handlers('validate', $elements, $form_state);
+}
+// Call any element-specific validators. These must act on the element
+// #value data.
+elseif (isset($elements['#element_validate'])) {
+foreach ($elements['#element_validate'] as $function) {
+$function($elements, $form_state, $form_state['complete form']);
+}
+}
+$elements['#validated'] = TRUE;
+}
+// Done validating this element, so turn off error suppression.
+// _form_validate() turns it on again when starting on the next element, if
+// it's still appropriate to do so.
+drupal_static_reset('form_set_error:limit_validation_errors');
+}
+/**
+* Executes custom validation and submission handlers for a given form.
+*
+* Button-specific handlers are checked first. If none exist, the function
+* falls back to form-level handlers.
+*
+* @param $type
+*   The type of handler to execute. 'validate' or 'submit' are the
+*   defaults used by Form API.
+* @param $form
+*   An associative array containing the structure of the form.
+* @param $form_state
+*   A keyed array containing the current state of the form. If the user
+*   submitted the form by clicking a button with custom handler functions
+*   defined, those handlers will be stored here.
+*/
+function form_execute_handlers($type, &$form, &$form_state) {
+$return = FALSE;
+// If there was a button pressed, use its handlers.
+if (isset($form_state[$type . '_handlers'])) {
+$handlers = $form_state[$type . '_handlers'];
+}
+// Otherwise, check for a form-level handler.
+elseif (isset($form['#' . $type])) {
+$handlers = $form['#' . $type];
+}
+else {
+$handlers = array();
+}
+foreach ($handlers as $function) {
+// Check if a previous _submit handler has set a batch, but make sure we
+// do not react to a batch that is already being processed (for instance
+// if a batch operation performs a drupal_form_submit()).
+if ($type == 'submit' && ($batch =& batch_get()) && !isset($batch['id'])) {
+// Some previous submit handler has set a batch. To ensure correct
+// execution order, store the call in a special 'control' batch set.
+// See _batch_next_set().
+$batch['sets'][] = array('form_submit' => $function);
+$batch['has_form_submits'] = TRUE;
+}
+else {
+$function($form, $form_state);
+}
+$return = TRUE;
+}
+return $return;
+}
+/**
+* Files an error against a form element.
+*
+* When a validation error is detected, the validator calls form_set_error() to
+* indicate which element needs to be changed and provide an error message. This
+* causes the Form API to not execute the form submit handlers, and instead to
+* re-display the form to the user with the corresponding elements rendered with
+* an 'error' CSS class (shown as red by default).
+*
+* The standard form_set_error() behavior can be changed if a button provides
+* the #limit_validation_errors property. Multistep forms not wanting to
+* validate the whole form can set #limit_validation_errors on buttons to
+* limit validation errors to only certain elements. For example, pressing the
+* "Previous" button in a multistep form should not fire validation errors just
+* because the current step has invalid values. If #limit_validation_errors is
+* set on a clicked button, the button must also define a #submit property
+* (may be set to an empty array). Any #submit handlers will be executed even if
+* there is invalid input, so extreme care should be taken with respect to any
+* actions taken by them. This is typically not a problem with buttons like
+* "Previous" or "Add more" that do not invoke persistent storage of the
+* submitted form values. Do not use the #limit_validation_errors property on
+* buttons that trigger saving of form values to the database.
+*
+* The #limit_validation_errors property is a list of "sections" within
+* $form_state['values'] that must contain valid values. Each "section" is an
+* array with the ordered set of keys needed to reach that part of
+* $form_state['values'] (i.e., the #parents property of the element).
+*
+* Example 1: Allow the "Previous" button to function, regardless of whether any
+* user input is valid.
+*
+* @code
+*   $form['actions']['previous'] = array(
+*     '#type' => 'submit',
+*     '#value' => t('Previous'),
+*     '#limit_validation_errors' => array(),       // No validation.
+*     '#submit' => array('some_submit_function'),  // #submit required.
+*   );
+* @endcode
+*
+* Example 2: Require some, but not all, user input to be valid to process the
+* submission of a "Previous" button.
+*
+* @code
+*   $form['actions']['previous'] = array(
+*     '#type' => 'submit',
+*     '#value' => t('Previous'),
+*     '#limit_validation_errors' => array(
+*       array('step1'),       // Validate $form_state['values']['step1'].
+*       array('foo', 'bar'),  // Validate $form_state['values']['foo']['bar'].
+*     ),
+*     '#submit' => array('some_submit_function'), // #submit required.
+*   );
+* @endcode
+*
+* This will require $form_state['values']['step1'] and everything within it
+* (for example, $form_state['values']['step1']['choice']) to be valid, so
+* calls to form_set_error('step1', $message) or
+* form_set_error('step1][choice', $message) will prevent the submit handlers
+* from running, and result in the error message being displayed to the user.
+* However, calls to form_set_error('step2', $message) and
+* form_set_error('step2][groupX][choiceY', $message) will be suppressed,
+* resulting in the message not being displayed to the user, and the submit
+* handlers will run despite $form_state['values']['step2'] and
+* $form_state['values']['step2']['groupX']['choiceY'] containing invalid
+* values. Errors for an invalid $form_state['values']['foo'] will be
+* suppressed, but errors flagging invalid values for
+* $form_state['values']['foo']['bar'] and everything within it will be
+* flagged and submission prevented.
+*
+* Partial form validation is implemented by suppressing errors rather than by
+* skipping the input processing and validation steps entirely, because some
+* forms have button-level submit handlers that call Drupal API functions that
+* assume that certain data exists within $form_state['values'], and while not
+* doing anything with that data that requires it to be valid, PHP errors
+* would be triggered if the input processing and validation steps were fully
+* skipped.
+*
+* @param $name
+*   The name of the form element. If the #parents property of your form
+*   element is array('foo', 'bar', 'baz') then you may set an error on 'foo'
+*   or 'foo][bar][baz'. Setting an error on 'foo' sets an error for every
+*   element where the #parents array starts with 'foo'.
+* @param $message
+*   The error message to present to the user.
+* @param $limit_validation_errors
+*   Internal use only. The #limit_validation_errors property of the clicked
+*   button, if it exists.
+*
+* @return
+*   Return value is for internal use only. To get a list of errors, use
+*   form_get_errors() or form_get_error().
+*
+* @see http://drupal.org/node/370537
+* @see http://drupal.org/node/763376
+*/
+function form_set_error($name = NULL, $message = '', $limit_validation_errors = NULL) {
+$form = &drupal_static(__FUNCTION__, array());
+$sections = &drupal_static(__FUNCTION__ . ':limit_validation_errors');
+if (isset($limit_validation_errors)) {
+$sections = $limit_validation_errors;
+}
+if (isset($name) && !isset($form[$name])) {
+$record = TRUE;
+if (isset($sections)) {
+// #limit_validation_errors is an array of "sections" within which user
+// input must be valid. If the element is within one of these sections,
+// the error must be recorded. Otherwise, it can be suppressed.
+// #limit_validation_errors can be an empty array, in which case all
+// errors are suppressed. For example, a "Previous" button might want its
+// submit action to be triggered even if none of the submitted values are
+// valid.
+$record = FALSE;
+foreach ($sections as $section) {
+// Exploding by '][' reconstructs the element's #parents. If the
+// reconstructed #parents begin with the same keys as the specified
+// section, then the element's values are within the part of
+// $form_state['values'] that the clicked button requires to be valid,
+// so errors for this element must be recorded. As the exploded array
+// will all be strings, we need to cast every value of the section
+// array to string.
+if (array_slice(explode('][', $name), 0, count($section)) === array_map('strval', $section)) {
+$record = TRUE;
+break;
+}
+}
+}
+if ($record) {
+$form[$name] = $message;
+if ($message) {
+drupal_set_message($message, 'error');
+}
+}
+}
+return $form;
+}
+/**
+* Clears all errors against all form elements made by form_set_error().
+*/
+function form_clear_error() {
+drupal_static_reset('form_set_error');
+}
+/**
+* Returns an associative array of all errors.
+*/
+function form_get_errors() {
+$form = form_set_error();
+if (!empty($form)) {
+return $form;
+}
+}
+/**
+* Returns the error message filed against the given form element.
+*
+* Form errors higher up in the form structure override deeper errors as well as
+* errors on the element itself.
+*/
+function form_get_error($element) {
+$form = form_set_error();
+$parents = array();
+foreach ($element['#parents'] as $parent) {
+$parents[] = $parent;
+$key = implode('][', $parents);
+if (isset($form[$key])) {
+return $form[$key];
+}
+}
+}
+/**
+* Flags an element as having an error.
+*/
+function form_error(&$element, $message = '') {
+form_set_error(implode('][', $element['#parents']), $message);
+}
+/**
+* Builds and processes all elements in the structured form array.
+*
+* Adds any required properties to each element, maps the incoming input data
+* to the proper elements, and executes any #process handlers attached to a
+* specific element.
+*
+* This is one of the three primary functions that recursively iterates a form
+* array. This one does it for completing the form building process. The other
+* two are _form_validate() (invoked via drupal_validate_form() and used to
+* invoke validation logic for each element) and drupal_render() (for rendering
+* each element). Each of these three pipelines provides ample opportunity for
+* modules to customize what happens. For example, during this function's life
+* cycle, the following functions get called for each element:
+* - $element['#value_callback']: A function that implements how user input is
+*   mapped to an element's #value property. This defaults to a function named
+*   'form_type_TYPE_value' where TYPE is $element['#type'].
+* - $element['#process']: An array of functions called after user input has
+*   been mapped to the element's #value property. These functions can be used
+*   to dynamically add child elements: for example, for the 'date' element
+*   type, one of the functions in this array is form_process_date(), which adds
+*   the individual 'year', 'month', 'day', etc. child elements. These functions
+*   can also be used to set additional properties or implement special logic
+*   other than adding child elements: for example, for the 'fieldset' element
+*   type, one of the functions in this array is form_process_fieldset(), which
+*   adds the attributes and JavaScript needed to make the fieldset collapsible
+*   if the #collapsible property is set. The #process functions are called in
+*   preorder traversal, meaning they are called for the parent element first,
+*   then for the child elements.
+* - $element['#after_build']: An array of functions called after form_builder()
+*   is done with its processing of the element. These are called in postorder
+*   traversal, meaning they are called for the child elements first, then for
+*   the parent element.
+* There are similar properties containing callback functions invoked by
+* _form_validate() and drupal_render(), appropriate for those operations.
+*
+* Developers are strongly encouraged to integrate the functionality needed by
+* their form or module within one of these three pipelines, using the
+* appropriate callback property, rather than implementing their own recursive
+* traversal of a form array. This facilitates proper integration between
+* multiple modules. For example, module developers are familiar with the
+* relative order in which hook_form_alter() implementations and #process
+* functions run. A custom traversal function that affects the building of a
+* form is likely to not integrate with hook_form_alter() and #process in the
+* expected way. Also, deep recursion within PHP is both slow and memory
+* intensive, so it is best to minimize how often it's done.
+*
+* As stated above, each element's #process functions are executed after its
+* #value has been set. This enables those functions to execute conditional
+* logic based on the current value. However, all of form_builder() runs before
+* drupal_validate_form() is called, so during #process function execution, the
+* element's #value has not yet been validated, so any code that requires
+* validated values must reside within a submit handler.
+*
+* As a security measure, user input is used for an element's #value only if the
+* element exists within $form, is not disabled (as per the #disabled property),
+* and can be accessed (as per the #access property, except that forms submitted
+* using drupal_form_submit() bypass #access restrictions). When user input is
+* ignored due to #disabled and #access restrictions, the element's default
+* value is used.
+*
+* Because of the preorder traversal, where #process functions of an element run
+* before user input for its child elements is processed, and because of the
+* Form API security of user input processing with respect to #access and
+* #disabled described above, this generally means that #process functions
+* should not use an element's (unvalidated) #value to affect the #disabled or
+* #access of child elements. Use-cases where a developer may be tempted to
+* implement such conditional logic usually fall into one of two categories:
+* - Where user input from the current submission must affect the structure of a
+*   form, including properties like #access and #disabled that affect how the
+*   next submission needs to be processed, a multi-step workflow is needed.
+*   This is most commonly implemented with a submit handler setting persistent
+*   data within $form_state based on *validated* values in
+*   $form_state['values'] and setting $form_state['rebuild']. The form building
+*   functions must then be implemented to use the $form_state data to rebuild
+*   the form with the structure appropriate for the new state.
+* - Where user input must affect the rendering of the form without affecting
+*   its structure, the necessary conditional rendering logic should reside
+*   within functions that run during the rendering phase (#pre_render, #theme,
+*   #theme_wrappers, and #post_render).
+*
+* @param $form_id
+*   A unique string identifying the form for validation, submission,
+*   theming, and hook_form_alter functions.
+* @param $element
+*   An associative array containing the structure of the current element.
+* @param $form_state
+*   A keyed array containing the current state of the form. In this
+*   context, it is used to accumulate information about which button
+*   was clicked when the form was submitted, as well as the sanitized
+*   $_POST data.
+*/
+function form_builder($form_id, &$element, &$form_state) {
+// Initialize as unprocessed.
+$element['#processed'] = FALSE;
+// Use element defaults.
+if (isset($element['#type']) && empty($element['#defaults_loaded']) && ($info = element_info($element['#type']))) {
+// Overlay $info onto $element, retaining preexisting keys in $element.
+$element += $info;
+$element['#defaults_loaded'] = TRUE;
+}
+// Assign basic defaults common for all form elements.
+$element += array(
+'#required' => FALSE,
+'#attributes' => array(),
+'#title_display' => 'before',
+);
+// Special handling if we're on the top level form element.
+if (isset($element['#type']) && $element['#type'] == 'form') {
+if (!empty($element['#https']) && variable_get('https', FALSE) &&
+!url_is_external($element['#action'])) {
+global $base_root;
+// Not an external URL so ensure that it is secure.
+$element['#action'] = str_replace('http://', 'https://', $base_root) . $element['#action'];
+}
+// Store a reference to the complete form in $form_state prior to building
+// the form. This allows advanced #process and #after_build callbacks to
+// perform changes elsewhere in the form.
+$form_state['complete form'] = &$element;
+// Set a flag if we have a correct form submission. This is always TRUE for
+// programmed forms coming from drupal_form_submit(), or if the form_id coming
+// from the POST data is set and matches the current form_id.
+if ($form_state['programmed'] || (!empty($form_state['input']) && (isset($form_state['input']['form_id']) && ($form_state['input']['form_id'] == $form_id)))) {
+$form_state['process_input'] = TRUE;
+// If the session token was set by drupal_prepare_form(), ensure that it
+// matches the current user's session.
+$form_state['invalid_token'] = FALSE;
+if (!empty($element['#token'])) {
+if (empty($form_state['input']['form_token']) || !drupal_valid_token($form_state['input']['form_token'], $element['#token'])) {
+// Set an early form error to block certain input processing since that
+// opens the door for CSRF vulnerabilities.
+_drupal_invalid_token_set_form_error();
+// This value is checked in _form_builder_handle_input_element().
+$form_state['invalid_token'] = TRUE;
+// Make sure file uploads do not get processed.
+$_FILES = array();
+}
+}
+}
+else {
+$form_state['process_input'] = FALSE;
+}
+// All form elements should have an #array_parents property.
+$element['#array_parents'] = array();
+}
+if (!isset($element['#id'])) {
+$element['#id'] = drupal_html_id('edit-' . implode('-', $element['#parents']));
+}
+// Handle input elements.
+if (!empty($element['#input'])) {
+_form_builder_handle_input_element($form_id, $element, $form_state);
+}
+// Allow for elements to expand to multiple elements, e.g., radios,
+// checkboxes and files.
+if (isset($element['#process']) && !$element['#processed']) {
+foreach ($element['#process'] as $process) {
+$element = $process($element, $form_state, $form_state['complete form']);
+}
+$element['#processed'] = TRUE;
+}
+// We start off assuming all form elements are in the correct order.
+$element['#sorted'] = TRUE;
+// Recurse through all child elements.
+$count = 0;
+foreach (element_children($element) as $key) {
+// Prior to checking properties of child elements, their default properties
+// need to be loaded.
+if (isset($element[$key]['#type']) && empty($element[$key]['#defaults_loaded']) && ($info = element_info($element[$key]['#type']))) {
+$element[$key] += $info;
+$element[$key]['#defaults_loaded'] = TRUE;
+}
+// Don't squash an existing tree value.
+if (!isset($element[$key]['#tree'])) {
+$element[$key]['#tree'] = $element['#tree'];
+}
+// Deny access to child elements if parent is denied.
+if (isset($element['#access']) && !$element['#access']) {
+$element[$key]['#access'] = FALSE;
+}
+// Make child elements inherit their parent's #disabled and #allow_focus
+// values unless they specify their own.
+foreach (array('#disabled', '#allow_focus') as $property) {
+if (isset($element[$property]) && !isset($element[$key][$property])) {
+$element[$key][$property] = $element[$property];
+}
+}
+// Don't squash existing parents value.
+if (!isset($element[$key]['#parents'])) {
+// Check to see if a tree of child elements is present. If so,
+// continue down the tree if required.
+$element[$key]['#parents'] = $element[$key]['#tree'] && $element['#tree'] ? array_merge($element['#parents'], array($key)) : array($key);
+}
+// Ensure #array_parents follows the actual form structure.
+$array_parents = $element['#array_parents'];
+$array_parents[] = $key;
+$element[$key]['#array_parents'] = $array_parents;
+// Assign a decimal placeholder weight to preserve original array order.
+if (!isset($element[$key]['#weight'])) {
+$element[$key]['#weight'] = $count/1000;
+}
+else {
+// If one of the child elements has a weight then we will need to sort
+// later.
+unset($element['#sorted']);
+}
+$element[$key] = form_builder($form_id, $element[$key], $form_state);
+$count++;
+}
+// The #after_build flag allows any piece of a form to be altered
+// after normal input parsing has been completed.
+if (isset($element['#after_build']) && !isset($element['#after_build_done'])) {
+foreach ($element['#after_build'] as $function) {
+$element = $function($element, $form_state);
+}
+$element['#after_build_done'] = TRUE;
+}
+// If there is a file element, we need to flip a flag so later the
+// form encoding can be set.
+if (isset($element['#type']) && $element['#type'] == 'file') {
+$form_state['has_file_element'] = TRUE;
+}
+// Final tasks for the form element after form_builder() has run for all other
+// elements.
+if (isset($element['#type']) && $element['#type'] == 'form') {
+// If there is a file element, we set the form encoding.
+if (isset($form_state['has_file_element'])) {
+$element['#attributes']['enctype'] = 'multipart/form-data';
+}
+// Allow Ajax submissions to the form action to bypass verification. This is
+// especially useful for multipart forms, which cannot be verified via a
+// response header.
+$element['#attached']['js'][] = array(
+'type' => 'setting',
+'data' => array(
+'urlIsAjaxTrusted' => array(
+$element['#action'] => TRUE,
+),
+),
+);
+// If a form contains a single textfield, and the ENTER key is pressed
+// within it, Internet Explorer submits the form with no POST data
+// identifying any submit button. Other browsers submit POST data as though
+// the user clicked the first button. Therefore, to be as consistent as we
+// can be across browsers, if no 'triggering_element' has been identified
+// yet, default it to the first button.
+if (!$form_state['programmed'] && !isset($form_state['triggering_element']) && !empty($form_state['buttons'])) {
+$form_state['triggering_element'] = $form_state['buttons'][0];
+}
+// If the triggering element specifies "button-level" validation and submit
+// handlers to run instead of the default form-level ones, then add those to
+// the form state.
+foreach (array('validate', 'submit') as $type) {
+if (isset($form_state['triggering_element']['#' . $type])) {
+$form_state[$type . '_handlers'] = $form_state['triggering_element']['#' . $type];
+}
+}
+// If the triggering element executes submit handlers, then set the form
+// state key that's needed for those handlers to run.
+if (!empty($form_state['triggering_element']['#executes_submit_callback'])) {
+$form_state['submitted'] = TRUE;
+}
+// Special processing if the triggering element is a button.
+if (isset($form_state['triggering_element']['#button_type'])) {
+// Because there are several ways in which the triggering element could
+// have been determined (including from input variables set by JavaScript
+// or fallback behavior implemented for IE), and because buttons often
+// have their #name property not derived from their #parents property, we
+// can't assume that input processing that's happened up until here has
+// resulted in $form_state['values'][BUTTON_NAME] being set. But it's
+// common for forms to have several buttons named 'op' and switch on
+// $form_state['values']['op'] during submit handler execution.
+$form_state['values'][$form_state['triggering_element']['#name']] = $form_state['triggering_element']['#value'];
+// @todo Legacy support. Remove in Drupal 8.
+$form_state['clicked_button'] = $form_state['triggering_element'];
+}
+}
+return $element;
+}
+/**
+* Adds the #name and #value properties of an input element before rendering.
+*/
+function _form_builder_handle_input_element($form_id, &$element, &$form_state) {
+static $safe_core_value_callbacks = array(
+'form_type_token_value',
+'form_type_textarea_value',
+'form_type_textfield_value',
+'form_type_checkbox_value',
+'form_type_checkboxes_value',
+'form_type_radios_value',
+'form_type_password_confirm_value',
+'form_type_select_value',
+'form_type_tableselect_value',
+'list_boolean_allowed_values_callback',
+);
+if (!isset($element['#name'])) {
+$name = array_shift($element['#parents']);
+$element['#name'] = $name;
+if ($element['#type'] == 'file') {
+// To make it easier to handle $_FILES in file.inc, we place all
+// file fields in the 'files' array. Also, we do not support
+// nested file names.
+$element['#name'] = 'files[' . $element['#name'] . ']';
+}
+elseif (count($element['#parents'])) {
+$element['#name'] .= '[' . implode('][', $element['#parents']) . ']';
+}
+array_unshift($element['#parents'], $name);
+}
+// Setting #disabled to TRUE results in user input being ignored, regardless
+// of how the element is themed or whether JavaScript is used to change the
+// control's attributes. However, it's good UI to let the user know that input
+// is not wanted for the control. HTML supports two attributes for this:
+// http://www.w3.org/TR/html401/interact/forms.html#h-17.12. If a form wants
+// to start a control off with one of these attributes for UI purposes only,
+// but still allow input to be processed if it's sumitted, it can set the
+// desired attribute in #attributes directly rather than using #disabled.
+// However, developers should think carefully about the accessibility
+// implications of doing so: if the form expects input to be enterable under
+// some condition triggered by JavaScript, how would someone who has
+// JavaScript disabled trigger that condition? Instead, developers should
+// consider whether a multi-step form would be more appropriate (#disabled can
+// be changed from step to step). If one still decides to use JavaScript to
+// affect when a control is enabled, then it is best for accessibility for the
+// control to be enabled in the HTML, and disabled by JavaScript on document
+// ready.
+if (!empty($element['#disabled'])) {
+if (!empty($element['#allow_focus'])) {
+$element['#attributes']['readonly'] = 'readonly';
+}
+else {
+$element['#attributes']['disabled'] = 'disabled';
+}
+}
+// With JavaScript or other easy hacking, input can be submitted even for
+// elements with #access=FALSE or #disabled=TRUE. For security, these must
+// not be processed. Forms that set #disabled=TRUE on an element do not
+// expect input for the element, and even forms submitted with
+// drupal_form_submit() must not be able to get around this. Forms that set
+// #access=FALSE on an element usually allow access for some users, so forms
+// submitted with drupal_form_submit() may bypass access restriction and be
+// treated as high-privilege users instead.
+$process_input = empty($element['#disabled']) && (($form_state['programmed'] && $form_state['programmed_bypass_access_check']) || ($form_state['process_input'] && (!isset($element['#access']) || $element['#access'])));
+// Set the element's #value property.
+if (!isset($element['#value']) && !array_key_exists('#value', $element)) {
+$value_callback = !empty($element['#value_callback']) ? $element['#value_callback'] : 'form_type_' . $element['#type'] . '_value';
+if ($process_input) {
+// Get the input for the current element. NULL values in the input need to
+// be explicitly distinguished from missing input. (see below)
+$input_exists = NULL;
+$input = drupal_array_get_nested_value($form_state['input'], $element['#parents'], $input_exists);
+// For browser-submitted forms, the submitted values do not contain values
+// for certain elements (empty multiple select, unchecked checkbox).
+// During initial form processing, we add explicit NULL values for such
+// elements in $form_state['input']. When rebuilding the form, we can
+// distinguish elements having NULL input from elements that were not part
+// of the initially submitted form and can therefore use default values
+// for the latter, if required. Programmatically submitted forms can
+// submit explicit NULL values when calling drupal_form_submit(), so we do
+// not modify $form_state['input'] for them.
+if (!$input_exists && !$form_state['rebuild'] && !$form_state['programmed']) {
+// Add the necessary parent keys to $form_state['input'] and sets the
+// element's input value to NULL.
+drupal_array_set_nested_value($form_state['input'], $element['#parents'], NULL);
+$input_exists = TRUE;
+}
+// If we have input for the current element, assign it to the #value
+// property, optionally filtered through $value_callback.
+if ($input_exists) {
+if (function_exists($value_callback)) {
+// Skip all value callbacks except safe ones like text if the CSRF
+// token was invalid.
+if (empty($form_state['invalid_token']) || in_array($value_callback, $safe_core_value_callbacks)) {
+$element['#value'] = $value_callback($element, $input, $form_state);
+}
+else {
+$input = NULL;
+}
+}
+if (!isset($element['#value']) && isset($input)) {
+$element['#value'] = $input;
+}
+}
+// Mark all posted values for validation.
+if (isset($element['#value']) || (!empty($element['#required']))) {
+$element['#needs_validation'] = TRUE;
+}
+}
+// Load defaults.
+if (!isset($element['#value'])) {
+// Call #type_value without a second argument to request default_value handling.
+if (function_exists($value_callback)) {
+$element['#value'] = $value_callback($element, FALSE, $form_state);
+}
+// Final catch. If we haven't set a value yet, use the explicit default value.
+// Avoid image buttons (which come with garbage value), so we only get value
+// for the button actually clicked.
+if (!isset($element['#value']) && empty($element['#has_garbage_value'])) {
+$element['#value'] = isset($element['#default_value']) ? $element['#default_value'] : '';
+}
+}
+}
+// Determine which element (if any) triggered the submission of the form and
+// keep track of all the clickable buttons in the form for
+// form_state_values_clean(). Enforce the same input processing restrictions
+// as above.
+if ($process_input) {
+// Detect if the element triggered the submission via Ajax.
+if (_form_element_triggered_scripted_submission($element, $form_state)) {
+$form_state['triggering_element'] = $element;
+}
+// If the form was submitted by the browser rather than via Ajax, then it
+// can only have been triggered by a button, and we need to determine which
+// button within the constraints of how browsers provide this information.
+if (isset($element['#button_type'])) {
+// All buttons in the form need to be tracked for
+// form_state_values_clean() and for the form_builder() code that handles
+// a form submission containing no button information in $_POST.
+$form_state['buttons'][] = $element;
+if (_form_button_was_clicked($element, $form_state)) {
+$form_state['triggering_element'] = $element;
+}
+}
+}
+// Set the element's value in $form_state['values'], but only, if its key
+// does not exist yet (a #value_callback may have already populated it).
+if (!drupal_array_nested_key_exists($form_state['values'], $element['#parents'])) {
+form_set_value($element, $element['#value'], $form_state);
+}
+}
+/**
+* Detects if an element triggered the form submission via Ajax.
+*
+* This detects button or non-button controls that trigger a form submission via
+* Ajax or some other scriptable environment. These environments can set the
+* special input key '_triggering_element_name' to identify the triggering
+* element. If the name alone doesn't identify the element uniquely, the input
+* key '_triggering_element_value' may also be set to require a match on element
+* value. An example where this is needed is if there are several buttons all
+* named 'op', and only differing in their value.
+*/
+function _form_element_triggered_scripted_submission($element, &$form_state) {
+if (!empty($form_state['input']['_triggering_element_name']) && $element['#name'] == $form_state['input']['_triggering_element_name']) {
+if (empty($form_state['input']['_triggering_element_value']) || $form_state['input']['_triggering_element_value'] == $element['#value']) {
+return TRUE;
+}
+}
+return FALSE;
+}
+/**
+* Determines if a given button triggered the form submission.
+*
+* This detects button controls that trigger a form submission by being clicked
+* and having the click processed by the browser rather than being captured by
+* JavaScript. Essentially, it detects if the button's name and value are part
+* of the POST data, but with extra code to deal with the convoluted way in
+* which browsers submit data for image button clicks.
+*
+* This does not detect button clicks processed by Ajax (that is done in
+* _form_element_triggered_scripted_submission()) and it does not detect form
+* submissions from Internet Explorer in response to an ENTER key pressed in a
+* textfield (form_builder() has extra code for that).
+*
+* Because this function contains only part of the logic needed to determine
+* $form_state['triggering_element'], it should not be called from anywhere
+* other than within the Form API. Form validation and submit handlers needing
+* to know which button was clicked should get that information from
+* $form_state['triggering_element'].
+*/
+function _form_button_was_clicked($element, &$form_state) {
+// First detect normal 'vanilla' button clicks. Traditionally, all
+// standard buttons on a form share the same name (usually 'op'),
+// and the specific return value is used to determine which was
+// clicked. This ONLY works as long as $form['#name'] puts the
+// value at the top level of the tree of $_POST data.
+if (isset($form_state['input'][$element['#name']]) && $form_state['input'][$element['#name']] == $element['#value']) {
+return TRUE;
+}
+// When image buttons are clicked, browsers do NOT pass the form element
+// value in $_POST. Instead they pass an integer representing the
+// coordinates of the click on the button image. This means that image
+// buttons MUST have unique $form['#name'] values, but the details of
+// their $_POST data should be ignored.
+elseif (!empty($element['#has_garbage_value']) && isset($element['#value']) && $element['#value'] !== '') {
+return TRUE;
+}
+return FALSE;
+}
+/**
+* Removes internal Form API elements and buttons from submitted form values.
+*
+* This function can be used when a module wants to store all submitted form
+* values, for example, by serializing them into a single database column. In
+* such cases, all internal Form API values and all form button elements should
+* not be contained, and this function allows to remove them before the module
+* proceeds to storage. Next to button elements, the following internal values
+* are removed:
+* - form_id
+* - form_token
+* - form_build_id
+* - op
+*
+* @param $form_state
+*   A keyed array containing the current state of the form, including
+*   submitted form values; altered by reference.
+*/
+function form_state_values_clean(&$form_state) {
+// Remove internal Form API values.
+unset($form_state['values']['form_id'], $form_state['values']['form_token'], $form_state['values']['form_build_id'], $form_state['values']['op']);
+// Remove button values.
+// form_builder() collects all button elements in a form. We remove the button
+// value separately for each button element.
+foreach ($form_state['buttons'] as $button) {
+// Remove this button's value from the submitted form values by finding
+// the value corresponding to this button.
+// We iterate over the #parents of this button and move a reference to
+// each parent in $form_state['values']. For example, if #parents is:
+//   array('foo', 'bar', 'baz')
+// then the corresponding $form_state['values'] part will look like this:
+// array(
+//   'foo' => array(
+//     'bar' => array(
+//       'baz' => 'button_value',
+//     ),
+//   ),
+// )
+// We start by (re)moving 'baz' to $last_parent, so we are able unset it
+// at the end of the iteration. Initially, $values will contain a
+// reference to $form_state['values'], but in the iteration we move the
+// reference to $form_state['values']['foo'], and finally to
+// $form_state['values']['foo']['bar'], which is the level where we can
+// unset 'baz' (that is stored in $last_parent).
+$parents = $button['#parents'];
+$last_parent = array_pop($parents);
+$key_exists = NULL;
+$values = &drupal_array_get_nested_value($form_state['values'], $parents, $key_exists);
+if ($key_exists && is_array($values)) {
+unset($values[$last_parent]);
+}
+}
+}
+/**
+* Determines the value for an image button form element.
+*
+* @param $form
+*   The form element whose value is being populated.
+* @param $input
+*   The incoming input to populate the form element. If this is FALSE,
+*   the element's default value should be returned.
+* @param $form_state
+*   A keyed array containing the current state of the form.
+*
+* @return
+*   The data that will appear in the $form_state['values'] collection
+*   for this element. Return nothing to use the default.
+*/
+function form_type_image_button_value($form, $input, $form_state) {
+if ($input !== FALSE) {
+if (!empty($input)) {
+// If we're dealing with Mozilla or Opera, we're lucky. It will
+// return a proper value, and we can get on with things.
+return $form['#return_value'];
+}
+else {
+// Unfortunately, in IE we never get back a proper value for THIS
+// form element. Instead, we get back two split values: one for the
+// X and one for the Y coordinates on which the user clicked the
+// button. We'll find this element in the #post data, and search
+// in the same spot for its name, with '_x'.
+$input = $form_state['input'];
+foreach (explode('[', $form['#name']) as $element_name) {
+// chop off the ] that may exist.
+if (substr($element_name, -1) == ']') {
+$element_name = substr($element_name, 0, -1);
+}
+if (!isset($input[$element_name])) {
+if (isset($input[$element_name . '_x'])) {
+return $form['#return_value'];
+}
+return NULL;
+}
+$input = $input[$element_name];
+}
+return $form['#return_value'];
+}
+}
+}
+/**
+* Determines the value for a checkbox form element.
+*
+* @param $form
+*   The form element whose value is being populated.
+* @param $input
+*   The incoming input to populate the form element. If this is FALSE,
+*   the element's default value should be returned.
+*
+* @return
+*   The data that will appear in the $element_state['values'] collection
+*   for this element. Return nothing to use the default.
+*/
+function form_type_checkbox_value($element, $input = FALSE) {
+if ($input === FALSE) {
+// Use #default_value as the default value of a checkbox, except change
+// NULL to 0, because _form_builder_handle_input_element() would otherwise
+// replace NULL with empty string, but an empty string is a potentially
+// valid value for a checked checkbox.
+return isset($element['#default_value']) ? $element['#default_value'] : 0;
+}
+else {
+// Checked checkboxes are submitted with a value (possibly '0' or ''):
+// http://www.w3.org/TR/html401/interact/forms.html#successful-controls.
+// For checked checkboxes, browsers submit the string version of
+// #return_value, but we return the original #return_value. For unchecked
+// checkboxes, browsers submit nothing at all, but
+// _form_builder_handle_input_element() detects this, and calls this
+// function with $input=NULL. Returning NULL from a value callback means to
+// use the default value, which is not what is wanted when an unchecked
+// checkbox is submitted, so we use integer 0 as the value indicating an
+// unchecked checkbox. Therefore, modules must not use integer 0 as a
+// #return_value, as doing so results in the checkbox always being treated
+// as unchecked. The string '0' is allowed for #return_value. The most
+// common use-case for setting #return_value to either 0 or '0' is for the
+// first option within a 0-indexed array of checkboxes, and for this,
+// form_process_checkboxes() uses the string rather than the integer.
+return isset($input) ? $element['#return_value'] : 0;
+}
+}
+/**
+* Determines the value for a checkboxes form element.
+*
+* @param $element
+*   The form element whose value is being populated.
+* @param $input
+*   The incoming input to populate the form element. If this is FALSE,
+*   the element's default value should be returned.
+*
+* @return
+*   The data that will appear in the $element_state['values'] collection
+*   for this element. Return nothing to use the default.
+*/
+function form_type_checkboxes_value($element, $input = FALSE) {
+if ($input === FALSE) {
+$value = array();
+$element += array('#default_value' => array());
+foreach ($element['#default_value'] as $key) {
+$value[$key] = $key;
+}
+return $value;
+}
+elseif (is_array($input)) {
+// Programmatic form submissions use NULL to indicate that a checkbox
+// should be unchecked; see drupal_form_submit(). We therefore remove all
+// NULL elements from the array before constructing the return value, to
+// simulate the behavior of web browsers (which do not send unchecked
+// checkboxes to the server at all). This will not affect non-programmatic
+// form submissions, since all values in $_POST are strings.
+foreach ($input as $key => $value) {
+if (!isset($value)) {
+unset($input[$key]);
+}
+}
+return drupal_map_assoc($input);
+}
+else {
+return array();
+}
+}
+/**
+* Determines the value for a tableselect form element.
+*
+* @param $element
+*   The form element whose value is being populated.
+* @param $input
+*   The incoming input to populate the form element. If this is FALSE,
+*   the element's default value should be returned.
+*
+* @return
+*   The data that will appear in the $element_state['values'] collection
+*   for this element. Return nothing to use the default.
+*/
+function form_type_tableselect_value($element, $input = FALSE) {
+// If $element['#multiple'] == FALSE, then radio buttons are displayed and
+// the default value handling is used.
+if (isset($element['#multiple']) && $element['#multiple']) {
+// Checkboxes are being displayed with the default value coming from the
+// keys of the #default_value property. This differs from the checkboxes
+// element which uses the array values.
+if ($input === FALSE) {
+$value = array();
+$element += array('#default_value' => array());
+foreach ($element['#default_value'] as $key => $flag) {
+if ($flag) {
+$value[$key] = $key;
+}
+}
+return $value;
+}
+else {
+return is_array($input) ? drupal_map_assoc($input) : array();
+}
+}
+}
+/**
+* Form value callback: Determines the value for a #type radios form element.
+*
+* @param $element
+*   The form element whose value is being populated.
+* @param $input
+*   (optional) The incoming input to populate the form element. If FALSE, the
+*   element's default value is returned. Defaults to FALSE.
+*
+* @return
+*   The data that will appear in the $element_state['values'] collection for
+*   this element.
+*/
+function form_type_radios_value(&$element, $input = FALSE) {
+if ($input !== FALSE) {
+// When there's user input (including NULL), return it as the value.
+// However, if NULL is submitted, _form_builder_handle_input_element() will
+// apply the default value, and we want that validated against #options
+// unless it's empty. (An empty #default_value, such as NULL or FALSE, can
+// be used to indicate that no radio button is selected by default.)
+if (!isset($input) && !empty($element['#default_value'])) {
+$element['#needs_validation'] = TRUE;
+}
+return $input;
+}
+else {
+// For default value handling, simply return #default_value. Additionally,
+// for a NULL default value, set #has_garbage_value to prevent
+// _form_builder_handle_input_element() converting the NULL to an empty
+// string, so that code can distinguish between nothing selected and the
+// selection of a radio button whose value is an empty string.
+$value = isset($element['#default_value']) ? $element['#default_value'] : NULL;
+if (!isset($value)) {
+$element['#has_garbage_value'] = TRUE;
+}
+return $value;
+}
+}
+/**
+* Determines the value for a password_confirm form element.
+*
+* @param $element
+*   The form element whose value is being populated.
+* @param $input
+*   The incoming input to populate the form element. If this is FALSE,
+*   the element's default value should be returned.
+*
+* @return
+*   The data that will appear in the $element_state['values'] collection
+*   for this element. Return nothing to use the default.
+*/
+function form_type_password_confirm_value($element, $input = FALSE) {
+if ($input === FALSE) {
+$element += array('#default_value' => array());
+return $element['#default_value'] + array('pass1' => '', 'pass2' => '');
+}
+$value = array('pass1' => '', 'pass2' => '');
+// Throw out all invalid array keys; we only allow pass1 and pass2.
+foreach ($value as $allowed_key => $default) {
+// These should be strings, but allow other scalars since they might be
+// valid input in programmatic form submissions. Any nested array values
+// are ignored.
+if (isset($input[$allowed_key]) && is_scalar($input[$allowed_key])) {
+$value[$allowed_key] = (string) $input[$allowed_key];
+}
+}
+return $value;
+}
+/**
+* Determines the value for a select form element.
+*
+* @param $element
+*   The form element whose value is being populated.
+* @param $input
+*   The incoming input to populate the form element. If this is FALSE,
+*   the element's default value should be returned.
+*
+* @return
+*   The data that will appear in the $element_state['values'] collection
+*   for this element. Return nothing to use the default.
+*/
+function form_type_select_value($element, $input = FALSE) {
+if ($input !== FALSE) {
+if (isset($element['#multiple']) && $element['#multiple']) {
+// If an enabled multi-select submits NULL, it means all items are
+// unselected. A disabled multi-select always submits NULL, and the
+// default value should be used.
+if (empty($element['#disabled'])) {
+return (is_array($input)) ? drupal_map_assoc($input) : array();
+}
+else {
+return (isset($element['#default_value']) && is_array($element['#default_value'])) ? $element['#default_value'] : array();
+}
+}
+// Non-multiple select elements may have an empty option preprended to them
+// (see form_process_select()). When this occurs, usually #empty_value is
+// an empty string, but some forms set #empty_value to integer 0 or some
+// other non-string constant. PHP receives all submitted form input as
+// strings, but if the empty option is selected, set the value to match the
+// empty value exactly.
+elseif (isset($element['#empty_value']) && $input === (string) $element['#empty_value']) {
+return $element['#empty_value'];
+}
+else {
+return $input;
+}
+}
+}
+/**
+* Determines the value for a textarea form element.
+*
+* @param array $element
+*   The form element whose value is being populated.
+* @param mixed $input
+*   The incoming input to populate the form element. If this is FALSE,
+*   the element's default value should be returned.
+*
+* @return string
+*   The data that will appear in the $element_state['values'] collection
+*   for this element. Return nothing to use the default.
+*/
+function form_type_textarea_value($element, $input = FALSE) {
+if ($input !== FALSE && $input !== NULL) {
+// This should be a string, but allow other scalars since they might be
+// valid input in programmatic form submissions.
+return is_scalar($input) ? (string) $input : '';
+}
+}
+/**
+* Determines the value for a textfield form element.
+*
+* @param $element
+*   The form element whose value is being populated.
+* @param $input
+*   The incoming input to populate the form element. If this is FALSE,
+*   the element's default value should be returned.
+*
+* @return
+*   The data that will appear in the $element_state['values'] collection
+*   for this element. Return nothing to use the default.
+*/
+function form_type_textfield_value($element, $input = FALSE) {
+if ($input !== FALSE && $input !== NULL) {
+// This should be a string, but allow other scalars since they might be
+// valid input in programmatic form submissions.
+if (!is_scalar($input)) {
+$input = '';
+}
+return str_replace(array("\r", "\n"), '', (string) $input);
+}
+}
+/**
+* Determines the value for form's token value.
+*
+* @param $element
+*   The form element whose value is being populated.
+* @param $input
+*   The incoming input to populate the form element. If this is FALSE,
+*   the element's default value should be returned.
+*
+* @return
+*   The data that will appear in the $element_state['values'] collection
+*   for this element. Return nothing to use the default.
+*/
+function form_type_token_value($element, $input = FALSE) {
+if ($input !== FALSE) {
+return (string) $input;
+}
+}
+/**
+* Changes submitted form values during form validation.
+*
+* Use this function to change the submitted value of a form element in a form
+* validation function, so that the changed value persists in $form_state
+* through the remaining validation and submission handlers. It does not change
+* the value in $element['#value'], only in $form_state['values'], which is
+* where submitted values are always stored.
+*
+* Note that form validation functions are specified in the '#validate'
+* component of the form array (the value of $form['#validate'] is an array of
+* validation function names). If the form does not originate in your module,
+* you can implement hook_form_FORM_ID_alter() to add a validation function
+* to $form['#validate'].
+*
+* @param $element
+*   The form element that should have its value updated; in most cases you can
+*   just pass in the element from the $form array, although the only component
+*   that is actually used is '#parents'. If constructing yourself, set
+*   $element['#parents'] to be an array giving the path through the form
+*   array's keys to the element whose value you want to update. For instance,
+*   if you want to update the value of $form['elem1']['elem2'], which should be
+*   stored in $form_state['values']['elem1']['elem2'], you would set
+*   $element['#parents'] = array('elem1','elem2').
+* @param $value
+*   The new value for the form element.
+* @param $form_state
+*   Form state array where the value change should be recorded.
+*/
+function form_set_value($element, $value, &$form_state) {
+drupal_array_set_nested_value($form_state['values'], $element['#parents'], $value, TRUE);
+}
+/**
+* Allows PHP array processing of multiple select options with the same value.
+*
+* Used for form select elements which need to validate HTML option groups
+* and multiple options which may return the same value. Associative PHP arrays
+* cannot handle these structures, since they share a common key.
+*
+* @param $array
+*   The form options array to process.
+*
+* @return
+*   An array with all hierarchical elements flattened to a single array.
+*/
+function form_options_flatten($array) {
+// Always reset static var when first entering the recursion.
+drupal_static_reset('_form_options_flatten');
+return _form_options_flatten($array);
+}
+/**
+* Iterates over an array and returns a flat array with duplicate keys removed.
+*
+* This function also handles cases where objects are passed as array values.
+*/
+function _form_options_flatten($array) {
+$return = &drupal_static(__FUNCTION__);
+foreach ($array as $key => $value) {
+if (is_object($value)) {
+_form_options_flatten($value->option);
+}
+elseif (is_array($value)) {
+_form_options_flatten($value);
+}
+else {
+$return[$key] = 1;
+}
+}
+return $return;
+}
+/**
+* Processes a select list form element.
+*
+* This process callback is mandatory for select fields, since all user agents
+* automatically preselect the first available option of single (non-multiple)
+* select lists.
+*
+* @param $element
+*   The form element to process. Properties used:
+*   - #multiple: (optional) Indicates whether one or more options can be
+*     selected. Defaults to FALSE.
+*   - #default_value: Must be NULL or not set in case there is no value for the
+*     element yet, in which case a first default option is inserted by default.
+*     Whether this first option is a valid option depends on whether the field
+*     is #required or not.
+*   - #required: (optional) Whether the user needs to select an option (TRUE)
+*     or not (FALSE). Defaults to FALSE.
+*   - #empty_option: (optional) The label to show for the first default option.
+*     By default, the label is automatically set to "- Select -" for a required
+*     field and "- None -" for an optional field.
+*   - #empty_value: (optional) The value for the first default option, which is
+*     used to determine whether the user submitted a value or not.
+*     - If #required is TRUE, this defaults to '' (an empty string).
+*     - If #required is not TRUE and this value isn't set, then no extra option
+*       is added to the select control, leaving the control in a slightly
+*       illogical state, because there's no way for the user to select nothing,
+*       since all user agents automatically preselect the first available
+*       option. But people are used to this being the behavior of select
+*       controls.
+*       @todo Address the above issue in Drupal 8.
+*     - If #required is not TRUE and this value is set (most commonly to an
+*       empty string), then an extra option (see #empty_option above)
+*       representing a "non-selection" is added with this as its value.
+*
+* @see _form_validate()
+*/
+function form_process_select($element) {
+// #multiple select fields need a special #name.
+if ($element['#multiple']) {
+$element['#attributes']['multiple'] = 'multiple';
+$element['#attributes']['name'] = $element['#name'] . '[]';
+}
+// A non-#multiple select needs special handling to prevent user agents from
+// preselecting the first option without intention. #multiple select lists do
+// not get an empty option, as it would not make sense, user interface-wise.
+else {
+$required = $element['#required'];
+// If the element is required and there is no #default_value, then add an
+// empty option that will fail validation, so that the user is required to
+// make a choice. Also, if there's a value for #empty_value or
+// #empty_option, then add an option that represents emptiness.
+if (($required && !isset($element['#default_value'])) || isset($element['#empty_value']) || isset($element['#empty_option'])) {
+$element += array(
+'#empty_value' => '',
+'#empty_option' => $required ? t('- Select -') : t('- None -'),
+);
+// The empty option is prepended to #options and purposively not merged
+// to prevent another option in #options mistakenly using the same value
+// as #empty_value.
+$empty_option = array($element['#empty_value'] => $element['#empty_option']);
+$element['#options'] = $empty_option + $element['#options'];
+}
+}
+return $element;
+}
+/**
+* Returns HTML for a select form element.
+*
+* It is possible to group options together; to do this, change the format of
+* $options to an associative array in which the keys are group labels, and the
+* values are associative arrays in the normal $options format.
+*
+* @param $variables
+*   An associative array containing:
+*   - element: An associative array containing the properties of the element.
+*     Properties used: #title, #value, #options, #description, #extra,
+*     #multiple, #required, #name, #attributes, #size.
+*
+* @ingroup themeable
+*/
+function theme_select($variables) {
+$element = $variables['element'];
+element_set_attributes($element, array('id', 'name', 'size'));
+_form_set_class($element, array('form-select'));
+return '<select' . drupal_attributes($element['#attributes']) . '>' . form_select_options($element) . '</select>';
+}
+/**
+* Converts an array of options into HTML, for use in select list form elements.
+*
+* This function calls itself recursively to obtain the values for each optgroup
+* within the list of options and when the function encounters an object with
+* an 'options' property inside $element['#options'].
+*
+* @param array $element
+*   An associative array containing the following key-value pairs:
+*   - #multiple: Optional Boolean indicating if the user may select more than
+*     one item.
+*   - #options: An associative array of options to render as HTML. Each array
+*     value can be a string, an array, or an object with an 'option' property:
+*     - A string or integer key whose value is a translated string is
+*       interpreted as a single HTML option element. Do not use placeholders
+*       that sanitize data: doing so will lead to double-escaping. Note that
+*       the key will be visible in the HTML and could be modified by malicious
+*       users, so don't put sensitive information in it.
+*     - A translated string key whose value is an array indicates a group of
+*       options. The translated string is used as the label attribute for the
+*       optgroup. Do not use placeholders to sanitize data: doing so will lead
+*       to double-escaping. The array should contain the options you wish to
+*       group and should follow the syntax of $element['#options'].
+*     - If the function encounters a string or integer key whose value is an
+*       object with an 'option' property, the key is ignored, the contents of
+*       the option property are interpreted as $element['#options'], and the
+*       resulting HTML is added to the output.
+*   - #value: Optional integer, string, or array representing which option(s)
+*     to pre-select when the list is first displayed. The integer or string
+*     must match the key of an option in the '#options' list. If '#multiple' is
+*     TRUE, this can be an array of integers or strings.
+* @param array|null $choices
+*   (optional) Either an associative array of options in the same format as
+*   $element['#options'] above, or NULL. This parameter is only used internally
+*   and is not intended to be passed in to the initial function call.
+*
+* @return string
+*   An HTML string of options and optgroups for use in a select form element.
+*/
+function form_select_options($element, $choices = NULL) {
+if (!isset($choices)) {
+$choices = $element['#options'];
+}
+// array_key_exists() accommodates the rare event where $element['#value'] is NULL.
+// isset() fails in this situation.
+$value_valid = isset($element['#value']) || array_key_exists('#value', $element);
+$value_is_array = $value_valid && is_array($element['#value']);
+$options = '';
+foreach ($choices as $key => $choice) {
+if (is_array($choice)) {
+$options .= '<optgroup label="' . check_plain($key) . '">';
+$options .= form_select_options($element, $choice);
+$options .= '</optgroup>';
+}
+elseif (is_object($choice)) {
+$options .= form_select_options($element, $choice->option);
+}
+else {
+$key = (string) $key;
+if ($value_valid && (!$value_is_array && (string) $element['#value'] === $key || ($value_is_array && in_array($key, $element['#value'])))) {
+$selected = ' selected="selected"';
+}
+else {
+$selected = '';
+}
+$options .= '<option value="' . check_plain($key) . '"' . $selected . '>' . check_plain($choice) . '</option>';
+}
+}
+return $options;
+}
+/**
+* Returns the indexes of a select element's options matching a given key.
+*
+* This function is useful if you need to modify the options that are
+* already in a form element; for example, to remove choices which are
+* not valid because of additional filters imposed by another module.
+* One example might be altering the choices in a taxonomy selector.
+* To correctly handle the case of a multiple hierarchy taxonomy,
+* #options arrays can now hold an array of objects, instead of a
+* direct mapping of keys to labels, so that multiple choices in the
+* selector can have the same key (and label). This makes it difficult
+* to manipulate directly, which is why this helper function exists.
+*
+* This function does not support optgroups (when the elements of the
+* #options array are themselves arrays), and will return FALSE if
+* arrays are found. The caller must either flatten/restore or
+* manually do their manipulations in this case, since returning the
+* index is not sufficient, and supporting this would make the
+* "helper" too complicated and cumbersome to be of any help.
+*
+* As usual with functions that can return array() or FALSE, do not
+* forget to use === and !== if needed.
+*
+* @param $element
+*   The select element to search.
+* @param $key
+*   The key to look for.
+*
+* @return
+*   An array of indexes that match the given $key. Array will be
+*   empty if no elements were found. FALSE if optgroups were found.
+*/
+function form_get_options($element, $key) {
+$keys = array();
+foreach ($element['#options'] as $index => $choice) {
+if (is_array($choice)) {
+return FALSE;
+}
+elseif (is_object($choice)) {
+if (isset($choice->option[$key])) {
+$keys[] = $index;
+}
+}
+elseif ($index == $key) {
+$keys[] = $index;
+}
+}
+return $keys;
+}
+/**
+* Returns HTML for a fieldset form element and its children.
+*
+* @param $variables
+*   An associative array containing:
+*   - element: An associative array containing the properties of the element.
+*     Properties used: #attributes, #children, #collapsed, #collapsible,
+*     #description, #id, #title, #value.
+*
+* @ingroup themeable
+*/
+function theme_fieldset($variables) {
+$element = $variables['element'];
+element_set_attributes($element, array('id'));
+_form_set_class($element, array('form-wrapper'));
+$output = '<fieldset' . drupal_attributes($element['#attributes']) . '>';
+if (!empty($element['#title'])) {
+// Always wrap fieldset legends in a SPAN for CSS positioning.
+$output .= '<legend><span class="fieldset-legend">' . $element['#title'] . '</span></legend>';
+}
+$output .= '<div class="fieldset-wrapper">';
+if (!empty($element['#description'])) {
+$output .= '<div class="fieldset-description">' . $element['#description'] . '</div>';
+}
+$output .= $element['#children'];
+if (isset($element['#value'])) {
+$output .= $element['#value'];
+}
+$output .= '</div>';
+$output .= "</fieldset>\n";
+return $output;
+}
+/**
+* Returns HTML for a radio button form element.
+*
+* Note: The input "name" attribute needs to be sanitized before output, which
+*       is currently done by passing all attributes to drupal_attributes().
+*
+* @param $variables
+*   An associative array containing:
+*   - element: An associative array containing the properties of the element.
+*     Properties used: #required, #return_value, #value, #attributes, #title,
+*     #description
+*
+* @ingroup themeable
+*/
+function theme_radio($variables) {
+$element = $variables['element'];
+$element['#attributes']['type'] = 'radio';
+element_set_attributes($element, array('id', 'name', '#return_value' => 'value'));
+if (isset($element['#return_value']) && $element['#value'] !== FALSE && $element['#value'] == $element['#return_value']) {
+$element['#attributes']['checked'] = 'checked';
+}
+_form_set_class($element, array('form-radio'));
+return '<input' . drupal_attributes($element['#attributes']) . ' />';
+}
+/**
+* Returns HTML for a set of radio button form elements.
+*
+* @param $variables
+*   An associative array containing:
+*   - element: An associative array containing the properties of the element.
+*     Properties used: #title, #value, #options, #description, #required,
+*     #attributes, #children.
+*
+* @ingroup themeable
+*/
+function theme_radios($variables) {
+$element = $variables['element'];
+$attributes = array();
+if (isset($element['#id'])) {
+$attributes['id'] = $element['#id'];
+}
+$attributes['class'] = 'form-radios';
+if (!empty($element['#attributes']['class'])) {
+$attributes['class'] .= ' ' . implode(' ', $element['#attributes']['class']);
+}
+if (isset($element['#attributes']['title'])) {
+$attributes['title'] = $element['#attributes']['title'];
+}
+return '<div' . drupal_attributes($attributes) . '>' . (!empty($element['#children']) ? $element['#children'] : '') . '</div>';
+}
+/**
+* Expand a password_confirm field into two text boxes.
+*/
+function form_process_password_confirm($element) {
+$element['pass1'] =  array(
+'#type' => 'password',
+'#title' => t('Password'),
+'#value' => empty($element['#value']) ? NULL : $element['#value']['pass1'],
+'#required' => $element['#required'],
+'#attributes' => array('class' => array('password-field')),
+);
+$element['pass2'] =  array(
+'#type' => 'password',
+'#title' => t('Confirm password'),
+'#value' => empty($element['#value']) ? NULL : $element['#value']['pass2'],
+'#required' => $element['#required'],
+'#attributes' => array('class' => array('password-confirm')),
+);
+$element['#element_validate'] = array('password_confirm_validate');
+$element['#tree'] = TRUE;
+if (isset($element['#size'])) {
+$element['pass1']['#size'] = $element['pass2']['#size'] = $element['#size'];
+}
+return $element;
+}
+/**
+* Validates a password_confirm element.
+*/
+function password_confirm_validate($element, &$element_state) {
+$pass1 = trim($element['pass1']['#value']);
+$pass2 = trim($element['pass2']['#value']);
+if (strlen($pass1) > 0 || strlen($pass2) > 0) {
+if (strcmp($pass1, $pass2)) {
+form_error($element, t('The specified passwords do not match.'));
+}
+}
+elseif ($element['#required'] && !empty($element_state['input'])) {
+form_error($element, t('Password field is required.'));
+}
+// Password field must be converted from a two-element array into a single
+// string regardless of validation results.
+form_set_value($element['pass1'], NULL, $element_state);
+form_set_value($element['pass2'], NULL, $element_state);
+form_set_value($element, $pass1, $element_state);
+return $element;
+}
+/**
+* Returns HTML for a date selection form element.
+*
+* @param $variables
+*   An associative array containing:
+*   - element: An associative array containing the properties of the element.
+*     Properties used: #title, #value, #options, #description, #required,
+*     #attributes.
+*
+* @ingroup themeable
+*/
+function theme_date($variables) {
+$element = $variables['element'];
+$attributes = array();
+if (isset($element['#id'])) {
+$attributes['id'] = $element['#id'];
+}
+if (!empty($element['#attributes']['class'])) {
+$attributes['class'] = (array) $element['#attributes']['class'];
+}
+$attributes['class'][] = 'container-inline';
+return '<div' . drupal_attributes($attributes) . '>' . drupal_render_children($element) . '</div>';
+}
+/**
+* Expands a date element into year, month, and day select elements.
+*/
+function form_process_date($element) {
+// Default to current date
+if (empty($element['#value'])) {
+$element['#value'] = array(
+'day' => format_date(REQUEST_TIME, 'custom', 'j'),
+'month' => format_date(REQUEST_TIME, 'custom', 'n'),
+'year' => format_date(REQUEST_TIME, 'custom', 'Y'),
+);
+}
+$element['#tree'] = TRUE;
+// Determine the order of day, month, year in the site's chosen date format.
+$format = variable_get('date_format_short', 'm/d/Y - H:i');
+$sort = array();
+$sort['day'] = max(strpos($format, 'd'), strpos($format, 'j'));
+$sort['month'] = max(strpos($format, 'm'), strpos($format, 'M'));
+$sort['year'] = strpos($format, 'Y');
+asort($sort);
+$order = array_keys($sort);
+// Output multi-selector for date.
+foreach ($order as $type) {
+switch ($type) {
+case 'day':
+$options = drupal_map_assoc(range(1, 31));
+$title = t('Day');
+break;
+case 'month':
+$options = drupal_map_assoc(range(1, 12), 'map_month');
+$title = t('Month');
+break;
+case 'year':
+$options = drupal_map_assoc(range(1900, 2050));
+$title = t('Year');
+break;
+}
+$element[$type] = array(
+'#type' => 'select',
+'#title' => $title,
+'#title_display' => 'invisible',
+'#value' => $element['#value'][$type],
+'#attributes' => $element['#attributes'],
+'#options' => $options,
+);
+}
+return $element;
+}
+/**
+* Validates the date type to prevent invalid dates (e.g., February 30, 2006).
+*/
+function date_validate($element) {
+if (!checkdate($element['#value']['month'], $element['#value']['day'], $element['#value']['year'])) {
+form_error($element, t('The specified date is invalid.'));
+}
+}
+/**
+* Helper function for usage with drupal_map_assoc to display month names.
+*/
+function map_month($month) {
+$months = &drupal_static(__FUNCTION__, array(
+1 => 'Jan',
+2 => 'Feb',
+3 => 'Mar',
+4 => 'Apr',
+5 => 'May',
+6 => 'Jun',
+7 => 'Jul',
+8 => 'Aug',
+9 => 'Sep',
+10 => 'Oct',
+11 => 'Nov',
+12 => 'Dec',
+));
+return t($months[$month]);
+}
+/**
+* Sets the value for a weight element, with zero as a default.
+*/
+function weight_value(&$form) {
+if (isset($form['#default_value'])) {
+$form['#value'] = $form['#default_value'];
+}
+else {
+$form['#value'] = 0;
+}
+}
+/**
+* Expands a radios element into individual radio elements.
+*/
+function form_process_radios($element) {
+if (count($element['#options']) > 0) {
+$weight = 0;
+foreach ($element['#options'] as $key => $choice) {
+// Maintain order of options as defined in #options, in case the element
+// defines custom option sub-elements, but does not define all option
+// sub-elements.
+$weight += 0.001;
+$element += array($key => array());
+// Generate the parents as the autogenerator does, so we will have a
+// unique id for each radio button.
+$parents_for_id = array_merge($element['#parents'], array($key));
+$element[$key] += array(
+'#type' => 'radio',
+'#title' => $choice,
+// The key is sanitized in drupal_attributes() during output from the
+// theme function.
+'#return_value' => $key,
+// Use default or FALSE. A value of FALSE means that the radio button is
+// not 'checked'.
+'#default_value' => isset($element['#default_value']) ? $element['#default_value'] : FALSE,
+'#attributes' => $element['#attributes'],
+'#parents' => $element['#parents'],
+'#id' => drupal_html_id('edit-' . implode('-', $parents_for_id)),
+'#ajax' => isset($element['#ajax']) ? $element['#ajax'] : NULL,
+'#weight' => $weight,
+);
+}
+}
+return $element;
+}
+/**
+* Returns HTML for a checkbox form element.
+*
+* @param $variables
+*   An associative array containing:
+*   - element: An associative array containing the properties of the element.
+*     Properties used: #id, #name, #attributes, #checked, #return_value.
+*
+* @ingroup themeable
+*/
+function theme_checkbox($variables) {
+$element = $variables['element'];
+$element['#attributes']['type'] = 'checkbox';
+element_set_attributes($element, array('id', 'name', '#return_value' => 'value'));
+// Unchecked checkbox has #value of integer 0.
+if (!empty($element['#checked'])) {
+$element['#attributes']['checked'] = 'checked';
+}
+_form_set_class($element, array('form-checkbox'));
+return '<input' . drupal_attributes($element['#attributes']) . ' />';
+}
+/**
+* Returns HTML for a set of checkbox form elements.
+*
+* @param $variables
+*   An associative array containing:
+*   - element: An associative array containing the properties of the element.
+*     Properties used: #children, #attributes.
+*
+* @ingroup themeable
+*/
+function theme_checkboxes($variables) {
+$element = $variables['element'];
+$attributes = array();
+if (isset($element['#id'])) {
+$attributes['id'] = $element['#id'];
+}
+$attributes['class'][] = 'form-checkboxes';
+if (!empty($element['#attributes']['class'])) {
+$attributes['class'] = array_merge($attributes['class'], $element['#attributes']['class']);
+}
+if (isset($element['#attributes']['title'])) {
+$attributes['title'] = $element['#attributes']['title'];
+}
+return '<div' . drupal_attributes($attributes) . '>' . (!empty($element['#children']) ? $element['#children'] : '') . '</div>';
+}
+/**
+* Adds form element theming to an element if its title or description is set.
+*
+* This is used as a pre render function for checkboxes and radios.
+*/
+function form_pre_render_conditional_form_element($element) {
+$t = get_t();
+// Set the element's title attribute to show #title as a tooltip, if needed.
+if (isset($element['#title']) && $element['#title_display'] == 'attribute') {
+$element['#attributes']['title'] = $element['#title'];
+if (!empty($element['#required'])) {
+// Append an indication that this field is required.
+$element['#attributes']['title'] .= ' (' . $t('Required') . ')';
+}
+}
+if (isset($element['#title']) || isset($element['#description'])) {
+$element['#theme_wrappers'][] = 'form_element';
+}
+return $element;
+}
+/**
+* Sets the #checked property of a checkbox element.
+*/
+function form_process_checkbox($element, $form_state) {
+$value = $element['#value'];
+$return_value = $element['#return_value'];
+// On form submission, the #value of an available and enabled checked
+// checkbox is #return_value, and the #value of an available and enabled
+// unchecked checkbox is integer 0. On not submitted forms, and for
+// checkboxes with #access=FALSE or #disabled=TRUE, the #value is
+// #default_value (integer 0 if #default_value is NULL). Most of the time,
+// a string comparison of #value and #return_value is sufficient for
+// determining the "checked" state, but a value of TRUE always means checked
+// (even if #return_value is 'foo'), and a value of FALSE or integer 0 always
+// means unchecked (even if #return_value is '' or '0').
+if ($value === TRUE || $value === FALSE || $value === 0) {
+$element['#checked'] = (bool) $value;
+}
+else {
+// Compare as strings, so that 15 is not considered equal to '15foo', but 1
+// is considered equal to '1'. This cast does not imply that either #value
+// or #return_value is expected to be a string.
+$element['#checked'] = ((string) $value === (string) $return_value);
+}
+return $element;
+}
+/**
+* Processes a checkboxes form element.
+*/
+function form_process_checkboxes($element) {
+$value = is_array($element['#value']) ? $element['#value'] : array();
+$element['#tree'] = TRUE;
+if (count($element['#options']) > 0) {
+if (!isset($element['#default_value']) || $element['#default_value'] == 0) {
+$element['#default_value'] = array();
+}
+$weight = 0;
+foreach ($element['#options'] as $key => $choice) {
+// Integer 0 is not a valid #return_value, so use '0' instead.
+// @see form_type_checkbox_value().
+// @todo For Drupal 8, cast all integer keys to strings for consistency
+//   with form_process_radios().
+if ($key === 0) {
+$key = '0';
+}
+// Maintain order of options as defined in #options, in case the element
+// defines custom option sub-elements, but does not define all option
+// sub-elements.
+$weight += 0.001;
+$element += array($key => array());
+$element[$key] += array(
+'#type' => 'checkbox',
+'#title' => $choice,
+'#return_value' => $key,
+'#default_value' => isset($value[$key]) ? $key : NULL,
+'#attributes' => $element['#attributes'],
+'#ajax' => isset($element['#ajax']) ? $element['#ajax'] : NULL,
+'#weight' => $weight,
+);
+}
+}
+return $element;
+}
+/**
+* Processes a form actions container element.
+*
+* @param $element
+*   An associative array containing the properties and children of the
+*   form actions container.
+* @param $form_state
+*   The $form_state array for the form this element belongs to.
+*
+* @return
+*   The processed element.
+*/
+function form_process_actions($element, &$form_state) {
+$element['#attributes']['class'][] = 'form-actions';
+return $element;
+}
+/**
+* Processes a container element.
+*
+* @param $element
+*   An associative array containing the properties and children of the
+*   container.
+* @param $form_state
+*   The $form_state array for the form this element belongs to.
+*
+* @return
+*   The processed element.
+*/
+function form_process_container($element, &$form_state) {
+// Generate the ID of the element if it's not explicitly given.
+if (!isset($element['#id'])) {
+$element['#id'] = drupal_html_id(implode('-', $element['#parents']) . '-wrapper');
+}
+return $element;
+}
+/**
+* Returns HTML to wrap child elements in a container.
+*
+* Used for grouped form items. Can also be used as a theme wrapper for any
+* renderable element, to surround it with a <div> and add attributes such as
+* classes or an HTML ID.
+*
+* See the @link forms_api_reference.html Form API reference @endlink for more
+* information on the #theme_wrappers render array property.
+*
+* @param $variables
+*   An associative array containing:
+*   - element: An associative array containing the properties of the element.
+*     Properties used: #id, #attributes, #children.
+*
+* @ingroup themeable
+*/
+function theme_container($variables) {
+$element = $variables['element'];
+// Ensure #attributes is set.
+$element += array('#attributes' => array());
+// Special handling for form elements.
+if (isset($element['#array_parents'])) {
+// Assign an html ID.
+if (!isset($element['#attributes']['id'])) {
+$element['#attributes']['id'] = $element['#id'];
+}
+// Add the 'form-wrapper' class.
+$element['#attributes']['class'][] = 'form-wrapper';
+}
+return '<div' . drupal_attributes($element['#attributes']) . '>' . $element['#children'] . '</div>';
+}
+/**
+* Returns HTML for a table with radio buttons or checkboxes.
+*
+* @param $variables
+*   An associative array containing:
+*   - element: An associative array containing the properties and children of
+*     the tableselect element. Properties used: #header, #options, #empty,
+*     and #js_select. The #options property is an array of selection options;
+*     each array element of #options is an array of properties. These
+*     properties can include #attributes, which is added to the
+*     table row's HTML attributes; see theme_table(). An example of per-row
+*     options:
+*     @code
+*     $options = array(
+*       array(
+*         'title' => 'How to Learn Drupal',
+*         'content_type' => 'Article',
+*         'status' => 'published',
+*         '#attributes' => array('class' => array('article-row')),
+*       ),
+*       array(
+*         'title' => 'Privacy Policy',
+*         'content_type' => 'Page',
+*         'status' => 'published',
+*         '#attributes' => array('class' => array('page-row')),
+*       ),
+*     );
+*     $header = array(
+*       'title' => t('Title'),
+*       'content_type' => t('Content type'),
+*       'status' => t('Status'),
+*     );
+*     $form['table'] = array(
+*       '#type' => 'tableselect',
+*       '#header' => $header,
+*       '#options' => $options,
+*       '#empty' => t('No content available.'),
+*     );
+*     @endcode
+*
+* @ingroup themeable
+*/
+function theme_tableselect($variables) {
+$element = $variables['element'];
+$rows = array();
+$header = $element['#header'];
+if (!empty($element['#options'])) {
+// Generate a table row for each selectable item in #options.
+foreach (element_children($element) as $key) {
+$row = array();
+$row['data'] = array();
+if (isset($element['#options'][$key]['#attributes'])) {
+$row += $element['#options'][$key]['#attributes'];
+}
+// Render the checkbox / radio element.
+$row['data'][] = drupal_render($element[$key]);
+// As theme_table only maps header and row columns by order, create the
+// correct order by iterating over the header fields.
+foreach ($element['#header'] as $fieldname => $title) {
+$row['data'][] = $element['#options'][$key][$fieldname];
+}
+$rows[] = $row;
+}
+// Add an empty header or a "Select all" checkbox to provide room for the
+// checkboxes/radios in the first table column.
+if ($element['#js_select']) {
+// Add a "Select all" checkbox.
+drupal_add_js('misc/tableselect.js');
+array_unshift($header, array('class' => array('select-all')));
+}
+else {
+// Add an empty header when radio buttons are displayed or a "Select all"
+// checkbox is not desired.
+array_unshift($header, '');
+}
+}
+return theme('table', array('header' => $header, 'rows' => $rows, 'empty' => $element['#empty'], 'attributes' => $element['#attributes']));
+}
+/**
+* Creates checkbox or radio elements to populate a tableselect table.
+*
+* @param $element
+*   An associative array containing the properties and children of the
+*   tableselect element.
+*
+* @return
+*   The processed element.
+*/
+function form_process_tableselect($element) {
+if ($element['#multiple']) {
+$value = is_array($element['#value']) ? $element['#value'] : array();
+}
+else {
+// Advanced selection behavior makes no sense for radios.
+$element['#js_select'] = FALSE;
+}
+$element['#tree'] = TRUE;
+if (count($element['#options']) > 0) {
+if (!isset($element['#default_value']) || $element['#default_value'] === 0) {
+$element['#default_value'] = array();
+}
+// Create a checkbox or radio for each item in #options in such a way that
+// the value of the tableselect element behaves as if it had been of type
+// checkboxes or radios.
+foreach ($element['#options'] as $key => $choice) {
+// Do not overwrite manually created children.
+if (!isset($element[$key])) {
+if ($element['#multiple']) {
+$title = '';
+if (!empty($element['#options'][$key]['title']['data']['#title'])) {
+$title = t('Update @title', array(
+'@title' => $element['#options'][$key]['title']['data']['#title'],
+));
+}
+$element[$key] = array(
+'#type' => 'checkbox',
+'#title' => $title,
+'#title_display' => 'invisible',
+'#return_value' => $key,
+'#default_value' => isset($value[$key]) ? $key : NULL,
+'#attributes' => $element['#attributes'],
+'#ajax' => isset($element['#ajax']) ? $element['#ajax'] : NULL,
+);
+}
+else {
+// Generate the parents as the autogenerator does, so we will have a
+// unique id for each radio button.
+$parents_for_id = array_merge($element['#parents'], array($key));
+$element[$key] = array(
+'#type' => 'radio',
+'#title' => '',
+'#return_value' => $key,
+'#default_value' => ($element['#default_value'] == $key) ? $key : NULL,
+'#attributes' => $element['#attributes'],
+'#parents' => $element['#parents'],
+'#id' => drupal_html_id('edit-' . implode('-', $parents_for_id)),
+'#ajax' => isset($element['#ajax']) ? $element['#ajax'] : NULL,
+);
+}
+if (isset($element['#options'][$key]['#weight'])) {
+$element[$key]['#weight'] = $element['#options'][$key]['#weight'];
+}
+}
+}
+}
+else {
+$element['#value'] = array();
+}
+return $element;
+}
+/**
+* Processes a machine-readable name form element.
+*
+* @param $element
+*   The form element to process. Properties used:
+*   - #machine_name: An associative array containing:
+*     - exists: A function name to invoke for checking whether a submitted
+*       machine name value already exists. The submitted value is passed as
+*       argument. In most cases, an existing API or menu argument loader
+*       function can be re-used. The callback is only invoked, if the submitted
+*       value differs from the element's #default_value.
+*     - source: (optional) The #array_parents of the form element containing
+*       the human-readable name (i.e., as contained in the $form structure) to
+*       use as source for the machine name. Defaults to array('name').
+*     - label: (optional) A text to display as label for the machine name value
+*       after the human-readable name form element. Defaults to "Machine name".
+*     - replace_pattern: (optional) A regular expression (without delimiters)
+*       matching disallowed characters in the machine name. Defaults to
+*       '[^a-z0-9_]+'.
+*     - replace: (optional) A character to replace disallowed characters in the
+*       machine name via JavaScript. Defaults to '_' (underscore). When using a
+*       different character, 'replace_pattern' needs to be set accordingly.
+*     - error: (optional) A custom form error message string to show, if the
+*       machine name contains disallowed characters.
+*     - standalone: (optional) Whether the live preview should stay in its own
+*       form element rather than in the suffix of the source element. Defaults
+*       to FALSE.
+*   - #maxlength: (optional) Should be set to the maximum allowed length of the
+*     machine name. Defaults to 64.
+*   - #disabled: (optional) Should be set to TRUE in case an existing machine
+*     name must not be changed after initial creation.
+*/
+function form_process_machine_name($element, &$form_state) {
+// Apply default form element properties.
+$element += array(
+'#title' => t('Machine-readable name'),
+'#description' => t('A unique machine-readable name. Can only contain lowercase letters, numbers, and underscores.'),
+'#machine_name' => array(),
+'#field_prefix' => '',
+'#field_suffix' => '',
+'#suffix' => '',
+);
+// A form element that only wants to set one #machine_name property (usually
+// 'source' only) would leave all other properties undefined, if the defaults
+// were defined in hook_element_info(). Therefore, we apply the defaults here.
+$element['#machine_name'] += array(
+'source' => array('name'),
+'target' => '#' . $element['#id'],
+'label' => t('Machine name'),
+'replace_pattern' => '[^a-z0-9_]+',
+'replace' => '_',
+'standalone' => FALSE,
+'field_prefix' => $element['#field_prefix'],
+'field_suffix' => $element['#field_suffix'],
+);
+// By default, machine names are restricted to Latin alphanumeric characters.
+// So, default to LTR directionality.
+if (!isset($element['#attributes'])) {
+$element['#attributes'] = array();
+}
+$element['#attributes'] += array('dir' => 'ltr');
+// The source element defaults to array('name'), but may have been overidden.
+if (empty($element['#machine_name']['source'])) {
+return $element;
+}
+// Retrieve the form element containing the human-readable name from the
+// complete form in $form_state. By reference, because we may need to append
+// a #field_suffix that will hold the live preview.
+$key_exists = NULL;
+$source = drupal_array_get_nested_value($form_state['complete form'], $element['#machine_name']['source'], $key_exists);
+if (!$key_exists) {
+return $element;
+}
+$suffix_id = $source['#id'] . '-machine-name-suffix';
+$element['#machine_name']['suffix'] = '#' . $suffix_id;
+if ($element['#machine_name']['standalone']) {
+$element['#suffix'] .= ' <small id="' . $suffix_id . '">&nbsp;</small>';
+}
+else {
+// Append a field suffix to the source form element, which will contain
+// the live preview of the machine name.
+$source += array('#field_suffix' => '');
+$source['#field_suffix'] .= ' <small id="' . $suffix_id . '">&nbsp;</small>';
+$parents = array_merge($element['#machine_name']['source'], array('#field_suffix'));
+drupal_array_set_nested_value($form_state['complete form'], $parents, $source['#field_suffix']);
+}
+$js_settings = array(
+'type' => 'setting',
+'data' => array(
+'machineName' => array(
+'#' . $source['#id'] => $element['#machine_name'],
+),
+),
+);
+$element['#attached']['js'][] = 'misc/machine-name.js';
+$element['#attached']['js'][] = $js_settings;
+return $element;
+}
+/**
+* Form element validation handler for machine_name elements.
+*
+* Note that #maxlength is validated by _form_validate() already.
+*/
+function form_validate_machine_name(&$element, &$form_state) {
+// Verify that the machine name not only consists of replacement tokens.
+if (preg_match('@^' . $element['#machine_name']['replace'] . '+$@', $element['#value'])) {
+form_error($element, t('The machine-readable name must contain unique characters.'));
+}
+// Verify that the machine name contains no disallowed characters.
+if (preg_match('@' . $element['#machine_name']['replace_pattern'] . '@', $element['#value'])) {
+if (!isset($element['#machine_name']['error'])) {
+// Since a hyphen is the most common alternative replacement character,
+// a corresponding validation error message is supported here.
+if ($element['#machine_name']['replace'] == '-') {
+form_error($element, t('The machine-readable name must contain only lowercase letters, numbers, and hyphens.'));
+}
+// Otherwise, we assume the default (underscore).
+else {
+form_error($element, t('The machine-readable name must contain only lowercase letters, numbers, and underscores.'));
+}
+}
+else {
+form_error($element, $element['#machine_name']['error']);
+}
+}
+// Verify that the machine name is unique.
+if ($element['#default_value'] !== $element['#value']) {
+$function = $element['#machine_name']['exists'];
+if ($function($element['#value'], $element, $form_state)) {
+form_error($element, t('The machine-readable name is already in use. It must be unique.'));
+}
+}
+}
+/**
+* Arranges fieldsets into groups.
+*
+* @param $element
+*   An associative array containing the properties and children of the
+*   fieldset. Note that $element must be taken by reference here, so processed
+*   child elements are taken over into $form_state.
+* @param $form_state
+*   The $form_state array for the form this fieldset belongs to.
+*
+* @return
+*   The processed element.
+*/
+function form_process_fieldset(&$element, &$form_state) {
+$parents = implode('][', $element['#parents']);
+// Each fieldset forms a new group. The #type 'vertical_tabs' basically only
+// injects a new fieldset.
+$form_state['groups'][$parents]['#group_exists'] = TRUE;
+$element['#groups'] = &$form_state['groups'];
+// Process vertical tabs group member fieldsets.
+if (isset($element['#group'])) {
+// Add this fieldset to the defined group (by reference).
+$group = $element['#group'];
+$form_state['groups'][$group][] = &$element;
+}
+// Contains form element summary functionalities.
+$element['#attached']['library'][] = array('system', 'drupal.form');
+// The .form-wrapper class is required for #states to treat fieldsets like
+// containers.
+if (!isset($element['#attributes']['class'])) {
+$element['#attributes']['class'] = array();
+}
+// Collapsible fieldsets
+if (!empty($element['#collapsible'])) {
+$element['#attached']['library'][] = array('system', 'drupal.collapse');
+$element['#attributes']['class'][] = 'collapsible';
+if (!empty($element['#collapsed'])) {
+$element['#attributes']['class'][] = 'collapsed';
+}
+}
+return $element;
+}
+/**
+* Adds members of this group as actual elements for rendering.
+*
+* @param $element
+*   An associative array containing the properties and children of the
+*   fieldset.
+*
+* @return
+*   The modified element with all group members.
+*/
+function form_pre_render_fieldset($element) {
+// Fieldsets may be rendered outside of a Form API context.
+if (!isset($element['#parents']) || !isset($element['#groups'])) {
+return $element;
+}
+// Inject group member elements belonging to this group.
+$parents = implode('][', $element['#parents']);
+$children = element_children($element['#groups'][$parents]);
+if (!empty($children)) {
+foreach ($children as $key) {
+// Break references and indicate that the element should be rendered as
+// group member.
+$child = (array) $element['#groups'][$parents][$key];
+$child['#group_fieldset'] = TRUE;
+// Inject the element as new child element.
+$element[] = $child;
+$sort = TRUE;
+}
+// Re-sort the element's children if we injected group member elements.
+if (isset($sort)) {
+$element['#sorted'] = FALSE;
+}
+}
+if (isset($element['#group'])) {
+$group = $element['#group'];
+// If this element belongs to a group, but the group-holding element does
+// not exist, we need to render it (at its original location).
+if (!isset($element['#groups'][$group]['#group_exists'])) {
+// Intentionally empty to clarify the flow; we simply return $element.
+}
+// If we injected this element into the group, then we want to render it.
+elseif (!empty($element['#group_fieldset'])) {
+// Intentionally empty to clarify the flow; we simply return $element.
+}
+// Otherwise, this element belongs to a group and the group exists, so we do
+// not render it.
+elseif (element_children($element['#groups'][$group])) {
+$element['#printed'] = TRUE;
+}
+}
+return $element;
+}
+/**
+* Creates a group formatted as vertical tabs.
+*
+* @param $element
+*   An associative array containing the properties and children of the
+*   fieldset.
+* @param $form_state
+*   The $form_state array for the form this vertical tab widget belongs to.
+*
+* @return
+*   The processed element.
+*/
+function form_process_vertical_tabs($element, &$form_state) {
+// Inject a new fieldset as child, so that form_process_fieldset() processes
+// this fieldset like any other fieldset.
+$element['group'] = array(
+'#type' => 'fieldset',
+'#theme_wrappers' => array(),
+'#parents' => $element['#parents'],
+);
+// The JavaScript stores the currently selected tab in this hidden
+// field so that the active tab can be restored the next time the
+// form is rendered, e.g. on preview pages or when form validation
+// fails.
+$name = implode('__', $element['#parents']);
+if (isset($form_state['values'][$name . '__active_tab'])) {
+$element['#default_tab'] = $form_state['values'][$name . '__active_tab'];
+}
+$element[$name . '__active_tab'] = array(
+'#type' => 'hidden',
+'#default_value' => $element['#default_tab'],
+'#attributes' => array('class' => array('vertical-tabs-active-tab')),
+);
+return $element;
+}
+/**
+* Returns HTML for an element's children fieldsets as vertical tabs.
+*
+* @param $variables
+*   An associative array containing:
+*   - element: An associative array containing the properties and children of
+*     the fieldset. Properties used: #children.
+*
+* @ingroup themeable
+*/
+function theme_vertical_tabs($variables) {
+$element = $variables['element'];
+// Add required JavaScript and Stylesheet.
+drupal_add_library('system', 'drupal.vertical-tabs');
+$output = '<h2 class="element-invisible">' . t('Vertical Tabs') . '</h2>';
+$output .= '<div class="vertical-tabs-panes">' . $element['#children'] . '</div>';
+return $output;
+}
+/**
+* Returns HTML for a submit button form element.
+*
+* @param $variables
+*   An associative array containing:
+*   - element: An associative array containing the properties of the element.
+*     Properties used: #attributes, #button_type, #name, #value.
+*
+* @ingroup themeable
+*/
+function theme_submit($variables) {
+return theme('button', $variables['element']);
+}
+/**
+* Returns HTML for a button form element.
+*
+* @param $variables
+*   An associative array containing:
+*   - element: An associative array containing the properties of the element.
+*     Properties used: #attributes, #button_type, #name, #value.
+*
+* @ingroup themeable
+*/
+function theme_button($variables) {
+$element = $variables['element'];
+$element['#attributes']['type'] = 'submit';
+element_set_attributes($element, array('id', 'name', 'value'));
+$element['#attributes']['class'][] = 'form-' . $element['#button_type'];
+if (!empty($element['#attributes']['disabled'])) {
+$element['#attributes']['class'][] = 'form-button-disabled';
+}
+return '<input' . drupal_attributes($element['#attributes']) . ' />';
+}
+/**
+* Returns HTML for an image button form element.
+*
+* @param $variables
+*   An associative array containing:
+*   - element: An associative array containing the properties of the element.
+*     Properties used: #attributes, #button_type, #name, #value, #title, #src.
+*
+* @ingroup themeable
+*/
+function theme_image_button($variables) {
+$element = $variables['element'];
+$element['#attributes']['type'] = 'image';
+element_set_attributes($element, array('id', 'name', 'value'));
+$element['#attributes']['src'] = file_create_url($element['#src']);
+if (!empty($element['#title'])) {
+$element['#attributes']['alt'] = $element['#title'];
+$element['#attributes']['title'] = $element['#title'];
+}
+$element['#attributes']['class'][] = 'form-' . $element['#button_type'];
+if (!empty($element['#attributes']['disabled'])) {
+$element['#attributes']['class'][] = 'form-button-disabled';
+}
+return '<input' . drupal_attributes($element['#attributes']) . ' />';
+}
+/**
+* Returns HTML for a hidden form element.
+*
+* @param $variables
+*   An associative array containing:
+*   - element: An associative array containing the properties of the element.
+*     Properties used: #name, #value, #attributes.
+*
+* @ingroup themeable
+*/
+function theme_hidden($variables) {
+$element = $variables['element'];
+$element['#attributes']['type'] = 'hidden';
+element_set_attributes($element, array('name', 'value'));
+return '<input' . drupal_attributes($element['#attributes']) . " />\n";
+}
+/**
+* Process function to prepare autocomplete data.
+*
+* @param $element
+*   A textfield or other element with a #autocomplete_path.
+*
+* @return array
+*   The processed form element.
+*/
+function form_process_autocomplete($element) {
+$element['#autocomplete_input'] = array();
+if ($element['#autocomplete_path'] && drupal_valid_path($element['#autocomplete_path'])) {
+$element['#autocomplete_input']['#id'] = $element['#id'] .'-autocomplete';
+// Force autocomplete to use non-clean URLs since this protects against the
+// browser interpreting the path plus search string as an actual file.
+$current_clean_url = isset($GLOBALS['conf']['clean_url']) ? $GLOBALS['conf']['clean_url'] : NULL;
+$GLOBALS['conf']['clean_url'] = 0;
+// Force the script path to 'index.php', in case the server is not
+// configured to find it automatically. Normally it is the responsibility
+// of the site to do this themselves using hook_url_outbound_alter() (see
+// url()) but since this code is forcing non-clean URLs on sites that don't
+// normally use them, it is done here instead.
+$element['#autocomplete_input']['#url_value'] = url($element['#autocomplete_path'], array('absolute' => TRUE, 'script' => 'index.php'));
+$GLOBALS['conf']['clean_url'] = $current_clean_url;
+}
+return $element;
+}
+/**
+* Returns HTML for a textfield form element.
+*
+* @param $variables
+*   An associative array containing:
+*   - element: An associative array containing the properties of the element.
+*     Properties used: #title, #value, #description, #size, #maxlength,
+*     #required, #attributes, #autocomplete_path.
+*
+* @ingroup themeable
+*/
+function theme_textfield($variables) {
+$element = $variables['element'];
+$element['#attributes']['type'] = 'text';
+element_set_attributes($element, array('id', 'name', 'value', 'size', 'maxlength'));
+_form_set_class($element, array('form-text'));
+$extra = '';
+if ($element['#autocomplete_path'] && !empty($element['#autocomplete_input'])) {
+drupal_add_library('system', 'drupal.autocomplete');
+$element['#attributes']['class'][] = 'form-autocomplete';
+$attributes = array();
+$attributes['type'] = 'hidden';
+$attributes['id'] = $element['#autocomplete_input']['#id'];
+$attributes['value'] = $element['#autocomplete_input']['#url_value'];
+$attributes['disabled'] = 'disabled';
+$attributes['class'][] = 'autocomplete';
+$extra = '<input' . drupal_attributes($attributes) . ' />';
+}
+$output = '<input' . drupal_attributes($element['#attributes']) . ' />';
+return $output . $extra;
+}
+/**
+* Returns HTML for a form.
+*
+* @param $variables
+*   An associative array containing:
+*   - element: An associative array containing the properties of the element.
+*     Properties used: #action, #method, #attributes, #children
+*
+* @ingroup themeable
+*/
+function theme_form($variables) {
+$element = $variables['element'];
+if (isset($element['#action'])) {
+$element['#attributes']['action'] = drupal_strip_dangerous_protocols($element['#action']);
+}
+element_set_attributes($element, array('method', 'id'));
+if (empty($element['#attributes']['accept-charset'])) {
+$element['#attributes']['accept-charset'] = "UTF-8";
+}
+// Anonymous DIV to satisfy XHTML compliance.
+return '<form' . drupal_attributes($element['#attributes']) . '><div>' . $element['#children'] . '</div></form>';
+}
+/**
+* Returns HTML for a textarea form element.
+*
+* @param $variables
+*   An associative array containing:
+*   - element: An associative array containing the properties of the element.
+*     Properties used: #title, #value, #description, #rows, #cols, #required,
+*     #attributes
+*
+* @ingroup themeable
+*/
+function theme_textarea($variables) {
+$element = $variables['element'];
+element_set_attributes($element, array('id', 'name', 'cols', 'rows'));
+_form_set_class($element, array('form-textarea'));
+$wrapper_attributes = array(
+'class' => array('form-textarea-wrapper'),
+);
+// Add resizable behavior.
+if (!empty($element['#resizable'])) {
+drupal_add_library('system', 'drupal.textarea');
+$wrapper_attributes['class'][] = 'resizable';
+}
+$output = '<div' . drupal_attributes($wrapper_attributes) . '>';
+$output .= '<textarea' . drupal_attributes($element['#attributes']) . '>' . check_plain($element['#value']) . '</textarea>';
+$output .= '</div>';
+return $output;
+}
+/**
+* Returns HTML for a password form element.
+*
+* @param $variables
+*   An associative array containing:
+*   - element: An associative array containing the properties of the element.
+*     Properties used: #title, #value, #description, #size, #maxlength,
+*     #required, #attributes.
+*
+* @ingroup themeable
+*/
+function theme_password($variables) {
+$element = $variables['element'];
+$element['#attributes']['type'] = 'password';
+element_set_attributes($element, array('id', 'name', 'size', 'maxlength'));
+_form_set_class($element, array('form-text'));
+return '<input' . drupal_attributes($element['#attributes']) . ' />';
+}
+/**
+* Expands a weight element into a select element.
+*/
+function form_process_weight($element) {
+$element['#is_weight'] = TRUE;
+// If the number of options is small enough, use a select field.
+$max_elements = variable_get('drupal_weight_select_max', DRUPAL_WEIGHT_SELECT_MAX);
+if ($element['#delta'] <= $max_elements) {
+$element['#type'] = 'select';
+for ($n = (-1 * $element['#delta']); $n <= $element['#delta']; $n++) {
+$weights[$n] = $n;
+}
+$element['#options'] = $weights;
+$element += element_info('select');
+}
+// Otherwise, use a text field.
+else {
+$element['#type'] = 'textfield';
+// Use a field big enough to fit most weights.
+$element['#size'] = 10;
+$element['#element_validate'] = array('element_validate_integer');
+$element += element_info('textfield');
+}
+return $element;
+}
+/**
+* Returns HTML for a file upload form element.
+*
+* For assistance with handling the uploaded file correctly, see the API
+* provided by file.inc.
+*
+* @param $variables
+*   An associative array containing:
+*   - element: An associative array containing the properties of the element.
+*     Properties used: #title, #name, #size, #description, #required,
+*     #attributes.
+*
+* @ingroup themeable
+*/
+function theme_file($variables) {
+$element = $variables['element'];
+$element['#attributes']['type'] = 'file';
+element_set_attributes($element, array('id', 'name', 'size'));
+_form_set_class($element, array('form-file'));
+return '<input' . drupal_attributes($element['#attributes']) . ' />';
+}
+/**
+* Returns HTML for a form element.
+*
+* Each form element is wrapped in a DIV container having the following CSS
+* classes:
+* - form-item: Generic for all form elements.
+* - form-type-#type: The internal element #type.
+* - form-item-#name: The internal form element #name (usually derived from the
+*   $form structure and set via form_builder()).
+* - form-disabled: Only set if the form element is #disabled.
+*
+* In addition to the element itself, the DIV contains a label for the element
+* based on the optional #title_display property, and an optional #description.
+*
+* The optional #title_display property can have these values:
+* - before: The label is output before the element. This is the default.
+*   The label includes the #title and the required marker, if #required.
+* - after: The label is output after the element. For example, this is used
+*   for radio and checkbox #type elements as set in system_element_info().
+*   If the #title is empty but the field is #required, the label will
+*   contain only the required marker.
+* - invisible: Labels are critical for screen readers to enable them to
+*   properly navigate through forms but can be visually distracting. This
+*   property hides the label for everyone except screen readers.
+* - attribute: Set the title attribute on the element to create a tooltip
+*   but output no label element. This is supported only for checkboxes
+*   and radios in form_pre_render_conditional_form_element(). It is used
+*   where a visual label is not needed, such as a table of checkboxes where
+*   the row and column provide the context. The tooltip will include the
+*   title and required marker.
+*
+* If the #title property is not set, then the label and any required marker
+* will not be output, regardless of the #title_display or #required values.
+* This can be useful in cases such as the password_confirm element, which
+* creates children elements that have their own labels and required markers,
+* but the parent element should have neither. Use this carefully because a
+* field without an associated label can cause accessibility challenges.
+*
+* @param $variables
+*   An associative array containing:
+*   - element: An associative array containing the properties of the element.
+*     Properties used: #title, #title_display, #description, #id, #required,
+*     #children, #type, #name.
+*
+* @ingroup themeable
+*/
+function theme_form_element($variables) {
+$element = &$variables['element'];
+// This function is invoked as theme wrapper, but the rendered form element
+// may not necessarily have been processed by form_builder().
+$element += array(
+'#title_display' => 'before',
+);
+// Add element #id for #type 'item'.
+if (isset($element['#markup']) && !empty($element['#id'])) {
+$attributes['id'] = $element['#id'];
+}
+// Add element's #type and #name as class to aid with JS/CSS selectors.
+$attributes['class'] = array('form-item');
+if (!empty($element['#type'])) {
+$attributes['class'][] = 'form-type-' . strtr($element['#type'], '_', '-');
+}
+if (!empty($element['#name'])) {
+$attributes['class'][] = 'form-item-' . strtr($element['#name'], array(' ' => '-', '_' => '-', '[' => '-', ']' => ''));
+}
+// Add a class for disabled elements to facilitate cross-browser styling.
+if (!empty($element['#attributes']['disabled'])) {
+$attributes['class'][] = 'form-disabled';
+}
+$output = '<div' . drupal_attributes($attributes) . '>' . "\n";
+// If #title is not set, we don't display any label or required marker.
+if (!isset($element['#title'])) {
+$element['#title_display'] = 'none';
+}
+$prefix = isset($element['#field_prefix']) ? '<span class="field-prefix">' . $element['#field_prefix'] . '</span> ' : '';
+$suffix = isset($element['#field_suffix']) ? ' <span class="field-suffix">' . $element['#field_suffix'] . '</span>' : '';
+switch ($element['#title_display']) {
+case 'before':
+case 'invisible':
+$output .= ' ' . theme('form_element_label', $variables);
+$output .= ' ' . $prefix . $element['#children'] . $suffix . "\n";
+break;
+case 'after':
+$output .= ' ' . $prefix . $element['#children'] . $suffix;
+$output .= ' ' . theme('form_element_label', $variables) . "\n";
+break;
+case 'none':
+case 'attribute':
+// Output no label and no required marker, only the children.
+$output .= ' ' . $prefix . $element['#children'] . $suffix . "\n";
+break;
+}
+if (!empty($element['#description'])) {
+$output .= '<div class="description">' . $element['#description'] . "</div>\n";
+}
+$output .= "</div>\n";
+return $output;
+}
+/**
+* Returns HTML for a marker for required form elements.
+*
+* @param $variables
+*   An associative array containing:
+*   - element: An associative array containing the properties of the element.
+*
+* @ingroup themeable
+*/
+function theme_form_required_marker($variables) {
+// This is also used in the installer, pre-database setup.
+$t = get_t();
+$attributes = array(
+'class' => 'form-required',
+'title' => $t('This field is required.'),
+);
+return '<span' . drupal_attributes($attributes) . '>*</span>';
+}
+/**
+* Returns HTML for a form element label and required marker.
+*
+* Form element labels include the #title and a #required marker. The label is
+* associated with the element itself by the element #id. Labels may appear
+* before or after elements, depending on theme_form_element() and
+* #title_display.
+*
+* This function will not be called for elements with no labels, depending on
+* #title_display. For elements that have an empty #title and are not required,
+* this function will output no label (''). For required elements that have an
+* empty #title, this will output the required marker alone within the label.
+* The label will use the #id to associate the marker with the field that is
+* required. That is especially important for screenreader users to know
+* which field is required.
+*
+* @param $variables
+*   An associative array containing:
+*   - element: An associative array containing the properties of the element.
+*     Properties used: #required, #title, #id, #value, #description.
+*
+* @ingroup themeable
+*/
+function theme_form_element_label($variables) {
+$element = $variables['element'];
+// This is also used in the installer, pre-database setup.
+$t = get_t();
+// If title and required marker are both empty, output no label.
+if ((!isset($element['#title']) || $element['#title'] === '') && empty($element['#required'])) {
+return '';
+}
+// If the element is required, a required marker is appended to the label.
+$required = !empty($element['#required']) ? theme('form_required_marker', array('element' => $element)) : '';
+$title = filter_xss_admin($element['#title']);
+$attributes = array();
+// Style the label as class option to display inline with the element.
+if ($element['#title_display'] == 'after') {
+$attributes['class'] = 'option';
+}
+// Show label only to screen readers to avoid disruption in visual flows.
+elseif ($element['#title_display'] == 'invisible') {
+$attributes['class'] = 'element-invisible';
+}
+if (!empty($element['#id'])) {
+$attributes['for'] = $element['#id'];
+}
+// The leading whitespace helps visually separate fields from inline labels.
+return ' <label' . drupal_attributes($attributes) . '>' . $t('!title !required', array('!title' => $title, '!required' => $required)) . "</label>\n";
+}
+/**
+* Sets a form element's class attribute.
+*
+* Adds 'required' and 'error' classes as needed.
+*
+* @param $element
+*   The form element.
+* @param $name
+*   Array of new class names to be added.
+*/
+function _form_set_class(&$element, $class = array()) {
+if (!empty($class)) {
+if (!isset($element['#attributes']['class'])) {
+$element['#attributes']['class'] = array();
+}
+$element['#attributes']['class'] = array_merge($element['#attributes']['class'], $class);
+}
+// This function is invoked from form element theme functions, but the
+// rendered form element may not necessarily have been processed by
+// form_builder().
+if (!empty($element['#required'])) {
+$element['#attributes']['class'][] = 'required';
+}
+if (isset($element['#parents']) && form_get_error($element) !== NULL && !empty($element['#validated'])) {
+$element['#attributes']['class'][] = 'error';
+}
+}
+/**
+* Form element validation handler for integer elements.
+*/
+function element_validate_integer($element, &$form_state) {
+$value = $element['#value'];
+if ($value !== '' && (!is_numeric($value) || intval($value) != $value)) {
+form_error($element, t('%name must be an integer.', array('%name' => $element['#title'])));
+}
+}
+/**
+* Form element validation handler for integer elements that must be positive.
+*/
+function element_validate_integer_positive($element, &$form_state) {
+$value = $element['#value'];
+if ($value !== '' && (!is_numeric($value) || intval($value) != $value || $value <= 0)) {
+form_error($element, t('%name must be a positive integer.', array('%name' => $element['#title'])));
+}
+}
+/**
+* Form element validation handler for number elements.
+*/
+function element_validate_number($element, &$form_state) {
+$value = $element['#value'];
+if ($value != '' && !is_numeric($value)) {
+form_error($element, t('%name must be a number.', array('%name' => $element['#title'])));
+}
+}
+/**
+* @} End of "defgroup form_api".
+*/
+/**
+* @defgroup batch Batch operations
+* @{
+* Creates and processes batch operations.
+*
+* Functions allowing forms processing to be spread out over several page
+* requests, thus ensuring that the processing does not get interrupted
+* because of a PHP timeout, while allowing the user to receive feedback
+* on the progress of the ongoing operations.
+*
+* The API is primarily designed to integrate nicely with the Form API
+* workflow, but can also be used by non-Form API scripts (like update.php)
+* or even simple page callbacks (which should probably be used sparingly).
+*
+* Example:
+* @code
+* $batch = array(
+*   'title' => t('Exporting'),
+*   'operations' => array(
+*     array('my_function_1', array($account->uid, 'story')),
+*     array('my_function_2', array()),
+*   ),
+*   'finished' => 'my_finished_callback',
+*   'file' => 'path_to_file_containing_myfunctions',
+* );
+* batch_set($batch);
+* // Only needed if not inside a form _submit handler.
+* // Setting redirect in batch_process.
+* batch_process('node/1');
+* @endcode
+*
+* Note: if the batch 'title', 'init_message', 'progress_message', or
+* 'error_message' could contain any user input, it is the responsibility of
+* the code calling batch_set() to sanitize them first with a function like
+* check_plain() or filter_xss(). Furthermore, if the batch operation
+* returns any user input in the 'results' or 'message' keys of $context,
+* it must also sanitize them first.
+*
+* Sample callback_batch_operation():
+* @code
+* // Simple and artificial: load a node of a given type for a given user
+* function my_function_1($uid, $type, &$context) {
+*   // The $context array gathers batch context information about the execution (read),
+*   // as well as 'return values' for the current operation (write)
+*   // The following keys are provided :
+*   // 'results' (read / write): The array of results gathered so far by
+*   //   the batch processing, for the current operation to append its own.
+*   // 'message' (write): A text message displayed in the progress page.
+*   // The following keys allow for multi-step operations :
+*   // 'sandbox' (read / write): An array that can be freely used to
+*   //   store persistent data between iterations. It is recommended to
+*   //   use this instead of $_SESSION, which is unsafe if the user
+*   //   continues browsing in a separate window while the batch is processing.
+*   // 'finished' (write): A float number between 0 and 1 informing
+*   //   the processing engine of the completion level for the operation.
+*   //   1 (or no value explicitly set) means the operation is finished
+*   //   and the batch processing can continue to the next operation.
+*
+*   $node = node_load(array('uid' => $uid, 'type' => $type));
+*   $context['results'][] = $node->nid . ' : ' . check_plain($node->title);
+*   $context['message'] = check_plain($node->title);
+* }
+*
+* // More advanced example: multi-step operation - load all nodes, five by five
+* function my_function_2(&$context) {
+*   if (empty($context['sandbox'])) {
+*     $context['sandbox']['progress'] = 0;
+*     $context['sandbox']['current_node'] = 0;
+*     $context['sandbox']['max'] = db_query('SELECT COUNT(DISTINCT nid) FROM {node}')->fetchField();
+*   }
+*   $limit = 5;
+*   $result = db_select('node')
+*     ->fields('node', array('nid'))
+*     ->condition('nid', $context['sandbox']['current_node'], '>')
+*     ->orderBy('nid')
+*     ->range(0, $limit)
+*     ->execute();
+*   foreach ($result as $row) {
+*     $node = node_load($row->nid, NULL, TRUE);
+*     $context['results'][] = $node->nid . ' : ' . check_plain($node->title);
+*     $context['sandbox']['progress']++;
+*     $context['sandbox']['current_node'] = $node->nid;
+*     $context['message'] = check_plain($node->title);
+*   }
+*   if ($context['sandbox']['progress'] != $context['sandbox']['max']) {
+*     $context['finished'] = $context['sandbox']['progress'] / $context['sandbox']['max'];
+*   }
+* }
+* @endcode
+*
+* Sample callback_batch_finished():
+* @code
+* function my_finished_callback($success, $results, $operations) {
+*   // The 'success' parameter means no fatal PHP errors were detected. All
+*   // other error management should be handled using 'results'.
+*   if ($success) {
+*     $message = format_plural(count($results), 'One post processed.', '@count posts processed.');
+*   }
+*   else {
+*     $message = t('Finished with an error.');
+*   }
+*   drupal_set_message($message);
+*   // Providing data for the redirected page is done through $_SESSION.
+*   foreach ($results as $result) {
+*     $items[] = t('Loaded node %title.', array('%title' => $result));
+*   }
+*   $_SESSION['my_batch_results'] = $items;
+* }
+* @endcode
+*/
+/**
+* Adds a new batch.
+*
+* Batch operations are added as new batch sets. Batch sets are used to spread
+* processing (primarily, but not exclusively, forms processing) over several
+* page requests. This helps to ensure that the processing is not interrupted
+* due to PHP timeouts, while users are still able to receive feedback on the
+* progress of the ongoing operations. Combining related operations into
+* distinct batch sets provides clean code independence for each batch set,
+* ensuring that two or more batches, submitted independently, can be processed
+* without mutual interference. Each batch set may specify its own set of
+* operations and results, produce its own UI messages, and trigger its own
+* 'finished' callback. Batch sets are processed sequentially, with the progress
+* bar starting afresh for each new set.
+*
+* @param $batch_definition
+*   An associative array defining the batch, with the following elements (all
+*   are optional except as noted):
+*   - operations: (required) Array of operations to be performed, where each
+*     item is an array consisting of the name of an implementation of
+*     callback_batch_operation() and an array of parameter.
+*     Example:
+*     @code
+*     array(
+*       array('callback_batch_operation_1', array($arg1)),
+*       array('callback_batch_operation_2', array($arg2_1, $arg2_2)),
+*     )
+*     @endcode
+*   - title: A safe, translated string to use as the title for the progress
+*     page. Defaults to t('Processing').
+*   - init_message: Message displayed while the processing is initialized.
+*     Defaults to t('Initializing.').
+*   - progress_message: Message displayed while processing the batch. Available
+*     placeholders are @current, @remaining, @total, @percentage, @estimate and
+*     @elapsed. Defaults to t('Completed @current of @total.').
+*   - error_message: Message displayed if an error occurred while processing
+*     the batch. Defaults to t('An error has occurred.').
+*   - finished: Name of an implementation of callback_batch_finished(). This is
+*     executed after the batch has completed. This should be used to perform
+*     any result massaging that may be needed, and possibly save data in
+*     $_SESSION for display after final page redirection.
+*   - file: Path to the file containing the definitions of the 'operations' and
+*     'finished' functions, for instance if they don't reside in the main
+*     .module file. The path should be relative to base_path(), and thus should
+*     be built using drupal_get_path().
+*   - css: Array of paths to CSS files to be used on the progress page.
+*   - url_options: options passed to url() when constructing redirect URLs for
+*     the batch.
+*/
+function batch_set($batch_definition) {
+if ($batch_definition) {
+$batch =& batch_get();
+// Initialize the batch if needed.
+if (empty($batch)) {
+$batch = array(
+'sets' => array(),
+'has_form_submits' => FALSE,
+);
+}
+// Base and default properties for the batch set.
+// Use get_t() to allow batches during installation.
+$t = get_t();
+$init = array(
+'sandbox' => array(),
+'results' => array(),
+'success' => FALSE,
+'start' => 0,
+'elapsed' => 0,
+);
+$defaults = array(
+'title' => $t('Processing'),
+'init_message' => $t('Initializing.'),
+'progress_message' => $t('Completed @current of @total.'),
+'error_message' => $t('An error has occurred.'),
+'css' => array(),
+);
+$batch_set = $init + $batch_definition + $defaults;
+// Tweak init_message to avoid the bottom of the page flickering down after
+// init phase.
+$batch_set['init_message'] .= '<br/>&nbsp;';
+// The non-concurrent workflow of batch execution allows us to save
+// numberOfItems() queries by handling our own counter.
+$batch_set['total'] = count($batch_set['operations']);
+$batch_set['count'] = $batch_set['total'];
+// Add the set to the batch.
+if (empty($batch['id'])) {
+// The batch is not running yet. Simply add the new set.
+$batch['sets'][] = $batch_set;
+}
+else {
+// The set is being added while the batch is running. Insert the new set
+// right after the current one to ensure execution order, and store its
+// operations in a queue.
+$index = $batch['current_set'] + 1;
+$slice1 = array_slice($batch['sets'], 0, $index);
+$slice2 = array_slice($batch['sets'], $index);
+$batch['sets'] = array_merge($slice1, array($batch_set), $slice2);
+_batch_populate_queue($batch, $index);
+}
+}
+}
+/**
+* Processes the batch.
+*
+* Unless the batch has been marked with 'progressive' = FALSE, the function
+* issues a drupal_goto and thus ends page execution.
+*
+* This function is generally not needed in form submit handlers;
+* Form API takes care of batches that were set during form submission.
+*
+* @param $redirect
+*   (optional) Path to redirect to when the batch has finished processing.
+* @param $url
+*   (optional - should only be used for separate scripts like update.php)
+*   URL of the batch processing page.
+* @param $redirect_callback
+*   (optional) Specify a function to be called to redirect to the progressive
+*   processing page. By default drupal_goto() will be used to redirect to a
+*   page which will do the progressive page. Specifying another function will
+*   allow the progressive processing to be processed differently.
+*/
+function batch_process($redirect = NULL, $url = 'batch', $redirect_callback = 'drupal_goto') {
+$batch =& batch_get();
+drupal_theme_initialize();
+if (isset($batch)) {
+// Add process information
+$process_info = array(
+'current_set' => 0,
+'progressive' => TRUE,
+'url' => $url,
+'url_options' => array(),
+'source_url' => $_GET['q'],
+'redirect' => $redirect,
+'theme' => $GLOBALS['theme_key'],
+'redirect_callback' => $redirect_callback,
+);
+$batch += $process_info;
+// The batch is now completely built. Allow other modules to make changes
+// to the batch so that it is easier to reuse batch processes in other
+// environments.
+drupal_alter('batch', $batch);
+// Assign an arbitrary id: don't rely on a serial column in the 'batch'
+// table, since non-progressive batches skip database storage completely.
+$batch['id'] = db_next_id();
+// Move operations to a job queue. Non-progressive batches will use a
+// memory-based queue.
+foreach ($batch['sets'] as $key => $batch_set) {
+_batch_populate_queue($batch, $key);
+}
+// Initiate processing.
+if ($batch['progressive']) {
+// Now that we have a batch id, we can generate the redirection link in
+// the generic error message.
+$t = get_t();
+$batch['error_message'] = $t('Please continue to <a href="@error_url">the error page</a>', array('@error_url' => url($url, array('query' => array('id' => $batch['id'], 'op' => 'finished')))));
+// Clear the way for the drupal_goto() redirection to the batch processing
+// page, by saving and unsetting the 'destination', if there is any.
+if (isset($_GET['destination'])) {
+$batch['destination'] = $_GET['destination'];
+unset($_GET['destination']);
+}
+// Store the batch.
+db_insert('batch')
+->fields(array(
+'bid' => $batch['id'],
+'timestamp' => REQUEST_TIME,
+'token' => drupal_get_token($batch['id']),
+'batch' => serialize($batch),
+))
+->execute();
+// Set the batch number in the session to guarantee that it will stay alive.
+$_SESSION['batches'][$batch['id']] = TRUE;
+// Redirect for processing.
+$function = $batch['redirect_callback'];
+if (function_exists($function)) {
+$function($batch['url'], array('query' => array('op' => 'start', 'id' => $batch['id'])));
+}
+}
+else {
+// Non-progressive execution: bypass the whole progressbar workflow
+// and execute the batch in one pass.
+require_once DRUPAL_ROOT . '/includes/batch.inc';
+_batch_process();
+}
+}
+}
+/**
+* Retrieves the current batch.
+*/
+function &batch_get() {
+// Not drupal_static(), because Batch API operates at a lower level than most
+// use-cases for resetting static variables, and we specifically do not want a
+// global drupal_static_reset() resetting the batch information. Functions
+// that are part of the Batch API and need to reset the batch information may
+// call batch_get() and manipulate the result by reference. Functions that are
+// not part of the Batch API can also do this, but shouldn't.
+static $batch = array();
+return $batch;
+}
+/**
+* Populates a job queue with the operations of a batch set.
+*
+* Depending on whether the batch is progressive or not, the BatchQueue or
+* BatchMemoryQueue handler classes will be used.
+*
+* @param $batch
+*   The batch array.
+* @param $set_id
+*   The id of the set to process.
+*
+* @return
+*   The name and class of the queue are added by reference to the batch set.
+*/
+function _batch_populate_queue(&$batch, $set_id) {
+$batch_set = &$batch['sets'][$set_id];
+if (isset($batch_set['operations'])) {
+$batch_set += array(
+'queue' => array(
+'name' => 'drupal_batch:' . $batch['id'] . ':' . $set_id,
+'class' => $batch['progressive'] ? 'BatchQueue' : 'BatchMemoryQueue',
+),
+);
+$queue = _batch_queue($batch_set);
+$queue->createQueue();
+foreach ($batch_set['operations'] as $operation) {
+$queue->createItem($operation);
+}
+unset($batch_set['operations']);
+}
+}
+/**
+* Returns a queue object for a batch set.
+*
+* @param $batch_set
+*   The batch set.
+*
+* @return
+*   The queue object.
+*/
+function _batch_queue($batch_set) {
+static $queues;
+// The class autoloader is not available when running update.php, so make
+// sure the files are manually included.
+if (!isset($queues)) {
+$queues = array();
+require_once DRUPAL_ROOT . '/modules/system/system.queue.inc';
+require_once DRUPAL_ROOT . '/includes/batch.queue.inc';
+}
+if (isset($batch_set['queue'])) {
+$name = $batch_set['queue']['name'];
+$class = $batch_set['queue']['class'];
+if (!isset($queues[$class][$name])) {
+$queues[$class][$name] = new $class($name);
+}
+return $queues[$class][$name];
+}
+}
+/**
+* @} End of "defgroup batch".
+*/