corpus_parole: comparison cms/drupal/modules/field/field.api.php

equal deleted inserted replaced

-:07239de796bb
+:e756a8c72c3d
+<?php
+/**
+* @file
+* Hooks provided by the Field module.
+*/
+/**
+* @addtogroup hooks
+* @{
+*/
+/**
+* Exposes "pseudo-field" components on fieldable entities.
+*
+* Field UI's "Manage fields" and "Manage display" pages let users re-order
+* fields, but also non-field components. For nodes, these include the title,
+* poll choices, and other elements exposed by modules through hook_form() or
+* hook_form_alter().
+*
+* Fieldable entities or modules that want to have their components supported
+* should expose them using this hook. The user-defined settings (weight,
+* visible) are automatically applied on rendered forms and displayed
+* entities in a #pre_render callback added by field_attach_form() and
+* field_attach_view().
+*
+* @see _field_extra_fields_pre_render()
+* @see hook_field_extra_fields_alter()
+*
+* @return
+*   A nested array of 'pseudo-field' elements. Each list is nested within the
+*   following keys: entity type, bundle name, context (either 'form' or
+*   'display'). The keys are the name of the elements as appearing in the
+*   renderable array (either the entity form or the displayed entity). The
+*   value is an associative array:
+*   - label: The human readable name of the element.
+*   - description: A short description of the element contents.
+*   - weight: The default weight of the element.
+*   - edit: (optional) String containing markup (normally a link) used as the
+*     element's 'edit' operation in the administration interface. Only for
+*     'form' context.
+*   - delete: (optional) String containing markup (normally a link) used as the
+*     element's 'delete' operation in the administration interface. Only for
+*     'form' context.
+*
+* @ingroup field_types
+*/
+function hook_field_extra_fields() {
+$extra['node']['poll'] = array(
+'form' => array(
+'choice_wrapper' => array(
+'label' => t('Poll choices'),
+'description' => t('Poll choices'),
+'weight' => -4,
+),
+'settings' => array(
+'label' => t('Poll settings'),
+'description' => t('Poll module settings'),
+'weight' => -3,
+),
+),
+'display' => array(
+'poll_view_voting' => array(
+'label' => t('Poll vote'),
+'description' => t('Poll vote'),
+'weight' => 0,
+),
+'poll_view_results' => array(
+'label' => t('Poll results'),
+'description' => t('Poll results'),
+'weight' => 0,
+),
+)
+);
+return $extra;
+}
+/**
+* Alter "pseudo-field" components on fieldable entities.
+*
+* @param $info
+*   The associative array of 'pseudo-field' components.
+*
+* @see hook_field_extra_fields()
+*
+* @ingroup field_types
+*/
+function hook_field_extra_fields_alter(&$info) {
+// Force node title to always be at the top of the list by default.
+foreach (node_type_get_types() as $bundle) {
+if (isset($info['node'][$bundle->type]['form']['title'])) {
+$info['node'][$bundle->type]['form']['title']['weight'] = -20;
+}
+}
+}
+/**
+* @defgroup field_types Field Types API
+* @{
+* Define field types.
+*
+* In the Field API, each field has a type, which determines what kind of data
+* (integer, string, date, etc.) the field can hold, which settings it provides,
+* and so on. The data type(s) accepted by a field are defined in
+* hook_field_schema(); other basic properties of a field are defined in
+* hook_field_info(). The other hooks below are called by the Field Attach API
+* to perform field-type-specific actions.
+*
+* The Field Types API also defines two kinds of pluggable handlers: widgets
+* and formatters. @link field_widget Widgets @endlink specify how the field
+* appears in edit forms, while @link field_formatter formatters @endlink
+* specify how the field appears in displayed entities.
+*
+* A third kind of pluggable handlers, storage backends, is defined by the
+* @link field_storage Field Storage API @endlink.
+*
+* See @link field Field API @endlink for information about the other parts of
+* the Field API.
+*/
+/**
+* Define Field API field types.
+*
+* Along with this hook, you also need to implement other hooks. See
+* @link field_types Field Types API @endlink for more information.
+*
+* @return
+*   An array whose keys are field type names and whose values are arrays
+*   describing the field type, with the following key/value pairs:
+*   - label: The human-readable name of the field type.
+*   - description: A short description for the field type.
+*   - settings: An array whose keys are the names of the settings available
+*     for the field type, and whose values are the default values for those
+*     settings.
+*   - instance_settings: An array whose keys are the names of the settings
+*     available for instances of the field type, and whose values are the
+*     default values for those settings. Instance-level settings can have
+*     different values on each field instance, and thus allow greater
+*     flexibility than field-level settings. It is recommended to put settings
+*     at the instance level whenever possible. Notable exceptions: settings
+*     acting on the schema definition, or settings that Views needs to use
+*     across field instances (for example, the list of allowed values).
+*   - default_widget: The machine name of the default widget to be used by
+*     instances of this field type, when no widget is specified in the
+*     instance definition. This widget must be available whenever the field
+*     type is available (i.e. provided by the field type module, or by a module
+*     the field type module depends on).
+*   - default_formatter: The machine name of the default formatter to be used
+*     by instances of this field type, when no formatter is specified in the
+*     instance definition. This formatter must be available whenever the field
+*     type is available (i.e. provided by the field type module, or by a module
+*     the field type module depends on).
+*   - no_ui: (optional) A boolean specifying that users should not be allowed
+*     to create fields and instances of this field type through the UI. Such
+*     fields can only be created programmatically with field_create_field()
+*     and field_create_instance(). Defaults to FALSE.
+*
+* @see hook_field_info_alter()
+*/
+function hook_field_info() {
+return array(
+'text' => array(
+'label' => t('Text'),
+'description' => t('This field stores varchar text in the database.'),
+'settings' => array('max_length' => 255),
+'instance_settings' => array('text_processing' => 0),
+'default_widget' => 'text_textfield',
+'default_formatter' => 'text_default',
+),
+'text_long' => array(
+'label' => t('Long text'),
+'description' => t('This field stores long text in the database.'),
+'settings' => array('max_length' => ''),
+'instance_settings' => array('text_processing' => 0),
+'default_widget' => 'text_textarea',
+'default_formatter' => 'text_default',
+),
+'text_with_summary' => array(
+'label' => t('Long text and summary'),
+'description' => t('This field stores long text in the database along with optional summary text.'),
+'settings' => array('max_length' => ''),
+'instance_settings' => array('text_processing' => 1, 'display_summary' => 0),
+'default_widget' => 'text_textarea_with_summary',
+'default_formatter' => 'text_summary_or_trimmed',
+),
+);
+}
+/**
+* Perform alterations on Field API field types.
+*
+* @param $info
+*   Array of information on field types exposed by hook_field_info()
+*   implementations.
+*/
+function hook_field_info_alter(&$info) {
+// Add a setting to all field types.
+foreach ($info as $field_type => $field_type_info) {
+$info[$field_type]['settings'] += array(
+'mymodule_additional_setting' => 'default value',
+);
+}
+// Change the default widget for fields of type 'foo'.
+if (isset($info['foo'])) {
+$info['foo']['default widget'] = 'mymodule_widget';
+}
+}
+/**
+* Define the Field API schema for a field structure.
+*
+* This is invoked when a field is created, in order to obtain the database
+* schema from the module that defines the field's type.
+*
+* This hook must be defined in the module's .install file for it to be detected
+* during installation and upgrade.
+*
+* @param $field
+*   A field structure.
+*
+* @return
+*   An associative array with the following keys:
+*   - columns: An array of Schema API column specifications, keyed by column
+*     name. This specifies what comprises a value for a given field. For
+*     example, a value for a number field is simply 'value', while a value for
+*     a formatted text field is the combination of 'value' and 'format'. It is
+*     recommended to avoid having the column definitions depend on field
+*     settings when possible. No assumptions should be made on how storage
+*     engines internally use the original column name to structure their
+*     storage.
+*   - indexes: (optional) An array of Schema API indexes definitions. Only
+*     columns that appear in the 'columns' array are allowed. Those indexes
+*     will be used as default indexes. Callers of field_create_field() can
+*     specify additional indexes, or, at their own risk, modify the default
+*     indexes specified by the field-type module. Some storage engines might
+*     not support indexes.
+*   - foreign keys: (optional) An array of Schema API foreign keys
+*     definitions.
+*/
+function hook_field_schema($field) {
+if ($field['type'] == 'text_long') {
+$columns = array(
+'value' => array(
+'type' => 'text',
+'size' => 'big',
+'not null' => FALSE,
+),
+);
+}
+else {
+$columns = array(
+'value' => array(
+'type' => 'varchar',
+'length' => $field['settings']['max_length'],
+'not null' => FALSE,
+),
+);
+}
+$columns += array(
+'format' => array(
+'type' => 'varchar',
+'length' => 255,
+'not null' => FALSE,
+),
+);
+return array(
+'columns' => $columns,
+'indexes' => array(
+'format' => array('format'),
+),
+'foreign keys' => array(
+'format' => array(
+'table' => 'filter_format',
+'columns' => array('format' => 'format'),
+),
+),
+);
+}
+/**
+* Define custom load behavior for this module's field types.
+*
+* Unlike most other field hooks, this hook operates on multiple entities. The
+* $entities, $instances and $items parameters are arrays keyed by entity ID.
+* For performance reasons, information for all available entity should be
+* loaded in a single query where possible.
+*
+* Note that the changes made to the field values get cached by the field cache
+* for subsequent loads. You should never use this hook to load fieldable
+* entities, since this is likely to cause infinite recursions when
+* hook_field_load() is run on those as well. Use
+* hook_field_formatter_prepare_view() instead.
+*
+* Make changes or additions to field values by altering the $items parameter by
+* reference. There is no return value.
+*
+* @param $entity_type
+*   The type of $entity.
+* @param $entities
+*   Array of entities being loaded, keyed by entity ID.
+* @param $field
+*   The field structure for the operation.
+* @param $instances
+*   Array of instance structures for $field for each entity, keyed by entity
+*   ID.
+* @param $langcode
+*   The language code associated with $items.
+* @param $items
+*   Array of field values already loaded for the entities, keyed by entity ID.
+*   Store your changes in this parameter (passed by reference).
+* @param $age
+*   FIELD_LOAD_CURRENT to load the most recent revision for all fields, or
+*   FIELD_LOAD_REVISION to load the version indicated by each entity.
+*/
+function hook_field_load($entity_type, $entities, $field, $instances, $langcode, &$items, $age) {
+// Sample code from text.module: precompute sanitized strings so they are
+// stored in the field cache.
+foreach ($entities as $id => $entity) {
+foreach ($items[$id] as $delta => $item) {
+// Only process items with a cacheable format, the rest will be handled
+// by formatters if needed.
+if (empty($instances[$id]['settings']['text_processing']) || filter_format_allowcache($item['format'])) {
+$items[$id][$delta]['safe_value'] = isset($item['value']) ? _text_sanitize($instances[$id], $langcode, $item, 'value') : '';
+if ($field['type'] == 'text_with_summary') {
+$items[$id][$delta]['safe_summary'] = isset($item['summary']) ? _text_sanitize($instances[$id], $langcode, $item, 'summary') : '';
+}
+}
+}
+}
+}
+/**
+* Prepare field values prior to display.
+*
+* This hook is invoked before the field values are handed to formatters
+* for display, and runs before the formatters' own
+* hook_field_formatter_prepare_view().
+*
+* Unlike most other field hooks, this hook operates on multiple entities. The
+* $entities, $instances and $items parameters are arrays keyed by entity ID.
+* For performance reasons, information for all available entities should be
+* loaded in a single query where possible.
+*
+* Make changes or additions to field values by altering the $items parameter by
+* reference. There is no return value.
+*
+* @param $entity_type
+*   The type of $entity.
+* @param $entities
+*   Array of entities being displayed, keyed by entity ID.
+* @param $field
+*   The field structure for the operation.
+* @param $instances
+*   Array of instance structures for $field for each entity, keyed by entity
+*   ID.
+* @param $langcode
+*   The language associated to $items.
+* @param $items
+*   $entity->{$field['field_name']}, or an empty array if unset.
+*/
+function hook_field_prepare_view($entity_type, $entities, $field, $instances, $langcode, &$items) {
+// Sample code from image.module: if there are no images specified at all,
+// use the default image.
+foreach ($entities as $id => $entity) {
+if (empty($items[$id]) && $field['settings']['default_image']) {
+if ($file = file_load($field['settings']['default_image'])) {
+$items[$id][0] = (array) $file + array(
+'is_default' => TRUE,
+'alt' => '',
+'title' => '',
+);
+}
+}
+}
+}
+/**
+* Validate this module's field data.
+*
+* If there are validation problems, add to the $errors array (passed by
+* reference). There is no return value.
+*
+* @param $entity_type
+*   The type of $entity.
+* @param $entity
+*   The entity for the operation.
+* @param $field
+*   The field structure for the operation.
+* @param $instance
+*   The instance structure for $field on $entity's bundle.
+* @param $langcode
+*   The language associated with $items.
+* @param $items
+*   $entity->{$field['field_name']}[$langcode], or an empty array if unset.
+* @param $errors
+*   The array of errors (keyed by field name, language code, and delta) that
+*   have already been reported for the entity. The function should add its
+*   errors to this array. Each error is an associative array with the following
+*   keys and values:
+*   - error: An error code (should be a string prefixed with the module name).
+*   - message: The human readable message to be displayed.
+*/
+function hook_field_validate($entity_type, $entity, $field, $instance, $langcode, $items, &$errors) {
+foreach ($items as $delta => $item) {
+if (!empty($item['value'])) {
+if (!empty($field['settings']['max_length']) && drupal_strlen($item['value']) > $field['settings']['max_length']) {
+$errors[$field['field_name']][$langcode][$delta][] = array(
+'error' => 'text_max_length',
+'message' => t('%name: the value may not be longer than %max characters.', array('%name' => $instance['label'], '%max' => $field['settings']['max_length'])),
+);
+}
+}
+}
+}
+/**
+* Define custom presave behavior for this module's field types.
+*
+* Make changes or additions to field values by altering the $items parameter by
+* reference. There is no return value.
+*
+* @param $entity_type
+*   The type of $entity.
+* @param $entity
+*   The entity for the operation.
+* @param $field
+*   The field structure for the operation.
+* @param $instance
+*   The instance structure for $field on $entity's bundle.
+* @param $langcode
+*   The language associated with $items.
+* @param $items
+*   $entity->{$field['field_name']}[$langcode], or an empty array if unset.
+*/
+function hook_field_presave($entity_type, $entity, $field, $instance, $langcode, &$items) {
+if ($field['type'] == 'number_decimal') {
+// Let PHP round the value to ensure consistent behavior across storage
+// backends.
+foreach ($items as $delta => $item) {
+if (isset($item['value'])) {
+$items[$delta]['value'] = round($item['value'], $field['settings']['scale']);
+}
+}
+}
+}
+/**
+* Define custom insert behavior for this module's field data.
+*
+* This hook is invoked from field_attach_insert() on the module that defines a
+* field, during the process of inserting an entity object (node, taxonomy term,
+* etc.). It is invoked just before the data for this field on the particular
+* entity object is inserted into field storage. Only field modules that are
+* storing or tracking information outside the standard field storage mechanism
+* need to implement this hook.
+*
+* @param $entity_type
+*   The type of $entity.
+* @param $entity
+*   The entity for the operation.
+* @param $field
+*   The field structure for the operation.
+* @param $instance
+*   The instance structure for $field on $entity's bundle.
+* @param $langcode
+*   The language associated with $items.
+* @param $items
+*   $entity->{$field['field_name']}[$langcode], or an empty array if unset.
+*
+* @see hook_field_update()
+* @see hook_field_delete()
+*/
+function hook_field_insert($entity_type, $entity, $field, $instance, $langcode, &$items) {
+if (variable_get('taxonomy_maintain_index_table', TRUE) && $field['storage']['type'] == 'field_sql_storage' && $entity_type == 'node' && $entity->status) {
+$query = db_insert('taxonomy_index')->fields(array('nid', 'tid', 'sticky', 'created', ));
+foreach ($items as $item) {
+$query->values(array(
+'nid' => $entity->nid,
+'tid' => $item['tid'],
+'sticky' => $entity->sticky,
+'created' => $entity->created,
+));
+}
+$query->execute();
+}
+}
+/**
+* Define custom update behavior for this module's field data.
+*
+* This hook is invoked from field_attach_update() on the module that defines a
+* field, during the process of updating an entity object (node, taxonomy term,
+* etc.). It is invoked just before the data for this field on the particular
+* entity object is updated into field storage. Only field modules that are
+* storing or tracking information outside the standard field storage mechanism
+* need to implement this hook.
+*
+* @param $entity_type
+*   The type of $entity.
+* @param $entity
+*   The entity for the operation.
+* @param $field
+*   The field structure for the operation.
+* @param $instance
+*   The instance structure for $field on $entity's bundle.
+* @param $langcode
+*   The language associated with $items.
+* @param $items
+*   $entity->{$field['field_name']}[$langcode], or an empty array if unset.
+*
+* @see hook_field_insert()
+* @see hook_field_delete()
+*/
+function hook_field_update($entity_type, $entity, $field, $instance, $langcode, &$items) {
+if (variable_get('taxonomy_maintain_index_table', TRUE) && $field['storage']['type'] == 'field_sql_storage' && $entity_type == 'node') {
+$first_call = &drupal_static(__FUNCTION__, array());
+// We don't maintain data for old revisions, so clear all previous values
+// from the table. Since this hook runs once per field, per object, make
+// sure we only wipe values once.
+if (!isset($first_call[$entity->nid])) {
+$first_call[$entity->nid] = FALSE;
+db_delete('taxonomy_index')->condition('nid', $entity->nid)->execute();
+}
+// Only save data to the table if the node is published.
+if ($entity->status) {
+$query = db_insert('taxonomy_index')->fields(array('nid', 'tid', 'sticky', 'created'));
+foreach ($items as $item) {
+$query->values(array(
+'nid' => $entity->nid,
+'tid' => $item['tid'],
+'sticky' => $entity->sticky,
+'created' => $entity->created,
+));
+}
+$query->execute();
+}
+}
+}
+/**
+* Update the storage information for a field.
+*
+* This is invoked on the field's storage module from field_update_field(),
+* before the new field information is saved to the database. The field storage
+* module should update its storage tables to agree with the new field
+* information. If there is a problem, the field storage module should throw an
+* exception.
+*
+* @param $field
+*   The updated field structure to be saved.
+* @param $prior_field
+*   The previously-saved field structure.
+* @param $has_data
+*   TRUE if the field has data in storage currently.
+*/
+function hook_field_storage_update_field($field, $prior_field, $has_data) {
+if (!$has_data) {
+// There is no data. Re-create the tables completely.
+$prior_schema = _field_sql_storage_schema($prior_field);
+foreach ($prior_schema as $name => $table) {
+db_drop_table($name, $table);
+}
+$schema = _field_sql_storage_schema($field);
+foreach ($schema as $name => $table) {
+db_create_table($name, $table);
+}
+}
+else {
+// There is data. See field_sql_storage_field_storage_update_field() for
+// an example of what to do to modify the schema in place, preserving the
+// old data as much as possible.
+}
+drupal_get_schema(NULL, TRUE);
+}
+/**
+* Define custom delete behavior for this module's field data.
+*
+* This hook is invoked from field_attach_delete() on the module that defines a
+* field, during the process of deleting an entity object (node, taxonomy term,
+* etc.). It is invoked just before the data for this field on the particular
+* entity object is deleted from field storage. Only field modules that are
+* storing or tracking information outside the standard field storage mechanism
+* need to implement this hook.
+*
+* @param $entity_type
+*   The type of $entity.
+* @param $entity
+*   The entity for the operation.
+* @param $field
+*   The field structure for the operation.
+* @param $instance
+*   The instance structure for $field on $entity's bundle.
+* @param $langcode
+*   The language associated with $items.
+* @param $items
+*   $entity->{$field['field_name']}[$langcode], or an empty array if unset.
+*
+* @see hook_field_insert()
+* @see hook_field_update()
+*/
+function hook_field_delete($entity_type, $entity, $field, $instance, $langcode, &$items) {
+list($id, $vid, $bundle) = entity_extract_ids($entity_type, $entity);
+foreach ($items as $delta => $item) {
+// For hook_file_references(), remember that this is being deleted.
+$item['file_field_name'] = $field['field_name'];
+// Pass in the ID of the object that is being removed so all references can
+// be counted in hook_file_references().
+$item['file_field_type'] = $entity_type;
+$item['file_field_id'] = $id;
+file_field_delete_file($item, $field, $entity_type, $id);
+}
+}
+/**
+* Define custom revision delete behavior for this module's field types.
+*
+* This hook is invoked just before the data is deleted from field storage
+* in field_attach_delete_revision(), and will only be called for fieldable
+* types that are versioned.
+*
+* @param $entity_type
+*   The type of $entity.
+* @param $entity
+*   The entity for the operation.
+* @param $field
+*   The field structure for the operation.
+* @param $instance
+*   The instance structure for $field on $entity's bundle.
+* @param $langcode
+*   The language associated with $items.
+* @param $items
+*   $entity->{$field['field_name']}[$langcode], or an empty array if unset.
+*/
+function hook_field_delete_revision($entity_type, $entity, $field, $instance, $langcode, &$items) {
+list($id, $vid, $bundle) = entity_extract_ids($entity_type, $entity);
+foreach ($items as $delta => $item) {
+// For hook_file_references, remember that this file is being deleted.
+$item['file_field_name'] = $field['field_name'];
+if (file_field_delete_file($item, $field, $entity_type, $id)) {
+$items[$delta] = NULL;
+}
+}
+}
+/**
+* Define custom prepare_translation behavior for this module's field types.
+*
+* @param $entity_type
+*   The type of $entity.
+* @param $entity
+*   The entity for the operation.
+* @param $field
+*   The field structure for the operation.
+* @param $instance
+*   The instance structure for $field on $entity's bundle.
+* @param $langcode
+*   The language associated to $items.
+* @param $items
+*   $entity->{$field['field_name']}[$langcode], or an empty array if unset.
+* @param $source_entity
+*   The source entity from which field values are being copied.
+* @param $source_langcode
+*   The source language from which field values are being copied.
+*
+* @ingroup field_language
+*/
+function hook_field_prepare_translation($entity_type, $entity, $field, $instance, $langcode, &$items, $source_entity, $source_langcode) {
+// If the translating user is not permitted to use the assigned text format,
+// we must not expose the source values.
+$field_name = $field['field_name'];
+$formats = filter_formats();
+$format_id = $source_entity->{$field_name}[$source_langcode][0]['format'];
+if (!filter_access($formats[$format_id])) {
+$items = array();
+}
+}
+/**
+* Define what constitutes an empty item for a field type.
+*
+* @param $item
+*   An item that may or may not be empty.
+* @param $field
+*   The field to which $item belongs.
+*
+* @return
+*   TRUE if $field's type considers $item not to contain any data;
+*   FALSE otherwise.
+*/
+function hook_field_is_empty($item, $field) {
+if (empty($item['value']) && (string) $item['value'] !== '0') {
+return TRUE;
+}
+return FALSE;
+}
+/**
+* @} End of "defgroup field_types".
+*/
+/**
+* @defgroup field_widget Field Widget API
+* @{
+* Define Field API widget types.
+*
+* Field API widgets specify how fields are displayed in edit forms. Fields of a
+* given @link field_types field type @endlink may be edited using more than one
+* widget. In this case, the Field UI module allows the site builder to choose
+* which widget to use. Widget types are defined by implementing
+* hook_field_widget_info().
+*
+* Widgets are @link forms_api_reference.html Form API @endlink elements with
+* additional processing capabilities. Widget hooks are typically called by the
+* Field Attach API during the creation of the field form structure with
+* field_attach_form().
+*
+* @see field
+* @see field_types
+* @see field_formatter
+*/
+/**
+* Expose Field API widget types.
+*
+* @return
+*   An array describing the widget types implemented by the module.
+*   The keys are widget type names. To avoid name clashes, widget type
+*   names should be prefixed with the name of the module that exposes them.
+*   The values are arrays describing the widget type, with the following
+*   key/value pairs:
+*   - label: The human-readable name of the widget type.
+*   - description: A short description for the widget type.
+*   - field types: An array of field types the widget supports.
+*   - settings: An array whose keys are the names of the settings available
+*     for the widget type, and whose values are the default values for those
+*     settings.
+*   - behaviors: (optional) An array describing behaviors of the widget, with
+*     the following elements:
+*     - multiple values: One of the following constants:
+*       - FIELD_BEHAVIOR_DEFAULT: (default) If the widget allows the input of
+*         one single field value (most common case). The widget will be
+*         repeated for each value input.
+*       - FIELD_BEHAVIOR_CUSTOM: If one single copy of the widget can receive
+*         several field values. Examples: checkboxes, multiple select,
+*         comma-separated textfield.
+*     - default value: One of the following constants:
+*       - FIELD_BEHAVIOR_DEFAULT: (default) If the widget accepts default
+*         values.
+*       - FIELD_BEHAVIOR_NONE: if the widget does not support default values.
+*   - weight: (optional) An integer to determine the weight of this widget
+*     relative to other widgets in the Field UI when selecting a widget for a
+*     given field instance.
+*
+* @see hook_field_widget_info_alter()
+* @see hook_field_widget_form()
+* @see hook_field_widget_form_alter()
+* @see hook_field_widget_WIDGET_TYPE_form_alter()
+* @see hook_field_widget_error()
+* @see hook_field_widget_settings_form()
+*/
+function hook_field_widget_info() {
+return array(
+'text_textfield' => array(
+'label' => t('Text field'),
+'field types' => array('text'),
+'settings' => array('size' => 60),
+'behaviors' => array(
+'multiple values' => FIELD_BEHAVIOR_DEFAULT,
+'default value' => FIELD_BEHAVIOR_DEFAULT,
+),
+),
+'text_textarea' => array(
+'label' => t('Text area (multiple rows)'),
+'field types' => array('text_long'),
+'settings' => array('rows' => 5),
+'behaviors' => array(
+'multiple values' => FIELD_BEHAVIOR_DEFAULT,
+'default value' => FIELD_BEHAVIOR_DEFAULT,
+),
+),
+'text_textarea_with_summary' => array(
+'label' => t('Text area with a summary'),
+'field types' => array('text_with_summary'),
+'settings' => array('rows' => 20, 'summary_rows' => 5),
+'behaviors' => array(
+'multiple values' => FIELD_BEHAVIOR_DEFAULT,
+'default value' => FIELD_BEHAVIOR_DEFAULT,
+),
+// As an advanced widget, force it to sink to the bottom of the choices.
+'weight' => 2,
+),
+);
+}
+/**
+* Perform alterations on Field API widget types.
+*
+* @param $info
+*   Array of informations on widget types exposed by hook_field_widget_info()
+*   implementations.
+*/
+function hook_field_widget_info_alter(&$info) {
+// Add a setting to a widget type.
+$info['text_textfield']['settings'] += array(
+'mymodule_additional_setting' => 'default value',
+);
+// Let a new field type re-use an existing widget.
+$info['options_select']['field types'][] = 'my_field_type';
+}
+/**
+* Return the form for a single field widget.
+*
+* Field widget form elements should be based on the passed-in $element, which
+* contains the base form element properties derived from the field
+* configuration.
+*
+* Field API will set the weight, field name and delta values for each form
+* element. If there are multiple values for this field, the Field API will
+* invoke this hook as many times as needed.
+*
+* Note that, depending on the context in which the widget is being included
+* (regular entity form, field configuration form, advanced search form...),
+* the values for $field and $instance might be different from the "official"
+* definitions returned by field_info_field() and field_info_instance().
+* Examples: mono-value widget even if the field is multi-valued, non-required
+* widget even if the field is 'required'...
+*
+* Therefore, the FAPI element callbacks (such as #process, #element_validate,
+* #value_callback...) used by the widget cannot use the field_info_field()
+* or field_info_instance() functions to retrieve the $field or $instance
+* definitions they should operate on. The field_widget_field() and
+* field_widget_instance() functions should be used instead to fetch the
+* current working definitions from $form_state, where Field API stores them.
+*
+* Alternatively, hook_field_widget_form() can extract the needed specific
+* properties from $field and $instance and set them as ad-hoc
+* $element['#custom'] properties, for later use by its element callbacks.
+*
+* Other modules may alter the form element provided by this function using
+* hook_field_widget_form_alter().
+*
+* @param $form
+*   The form structure where widgets are being attached to. This might be a
+*   full form structure, or a sub-element of a larger form.
+* @param $form_state
+*   An associative array containing the current state of the form.
+* @param $field
+*   The field structure.
+* @param $instance
+*   The field instance.
+* @param $langcode
+*   The language associated with $items.
+* @param $items
+*   Array of default values for this field.
+* @param $delta
+*   The order of this item in the array of subelements (0, 1, 2, etc).
+* @param $element
+*   A form element array containing basic properties for the widget:
+*   - #entity_type: The name of the entity the field is attached to.
+*   - #bundle: The name of the field bundle the field is contained in.
+*   - #field_name: The name of the field.
+*   - #language: The language the field is being edited in.
+*   - #field_parents: The 'parents' space for the field in the form. Most
+*       widgets can simply overlook this property. This identifies the
+*       location where the field values are placed within
+*       $form_state['values'], and is used to access processing information
+*       for the field through the field_form_get_state() and
+*       field_form_set_state() functions.
+*   - #columns: A list of field storage columns of the field.
+*   - #title: The sanitized element label for the field instance, ready for
+*     output.
+*   - #description: The sanitized element description for the field instance,
+*     ready for output.
+*   - #required: A Boolean indicating whether the element value is required;
+*     for required multiple value fields, only the first widget's values are
+*     required.
+*   - #delta: The order of this item in the array of subelements; see $delta
+*     above.
+*
+* @return
+*   The form elements for a single widget for this field.
+*
+* @see field_widget_field()
+* @see field_widget_instance()
+* @see hook_field_widget_form_alter()
+* @see hook_field_widget_WIDGET_TYPE_form_alter()
+*/
+function hook_field_widget_form(&$form, &$form_state, $field, $instance, $langcode, $items, $delta, $element) {
+$element += array(
+'#type' => $instance['widget']['type'],
+'#default_value' => isset($items[$delta]) ? $items[$delta] : '',
+);
+return array('value' => $element);
+}
+/**
+* Alter forms for field widgets provided by other modules.
+*
+* @param $element
+*   The field widget form element as constructed by hook_field_widget_form().
+* @param $form_state
+*   An associative array containing the current state of the form.
+* @param $context
+*   An associative array containing the following key-value pairs, matching the
+*   arguments received by hook_field_widget_form():
+*   - form: The form structure to which widgets are being attached. This may be
+*     a full form structure, or a sub-element of a larger form.
+*   - field: The field structure.
+*   - instance: The field instance structure.
+*   - langcode: The language associated with $items.
+*   - items: Array of default values for this field.
+*   - delta: The order of this item in the array of subelements (0, 1, 2, etc).
+*
+* @see hook_field_widget_form()
+* @see hook_field_widget_WIDGET_TYPE_form_alter()
+*/
+function hook_field_widget_form_alter(&$element, &$form_state, $context) {
+// Add a css class to widget form elements for all fields of type mytype.
+if ($context['field']['type'] == 'mytype') {
+// Be sure not to overwrite existing attributes.
+$element['#attributes']['class'][] = 'myclass';
+}
+}
+/**
+* Alter widget forms for a specific widget provided by another module.
+*
+* Modules can implement hook_field_widget_WIDGET_TYPE_form_alter() to modify a
+* specific widget form, rather than using hook_field_widget_form_alter() and
+* checking the widget type.
+*
+* @param $element
+*   The field widget form element as constructed by hook_field_widget_form().
+* @param $form_state
+*   An associative array containing the current state of the form.
+* @param $context
+*   An associative array containing the following key-value pairs, matching the
+*   arguments received by hook_field_widget_form():
+*   - "form": The form structure where widgets are being attached to. This
+*     might be a full form structure, or a sub-element of a larger form.
+*   - "field": The field structure.
+*   - "instance": The field instance structure.
+*   - "langcode": The language associated with $items.
+*   - "items": Array of default values for this field.
+*   - "delta": The order of this item in the array of subelements (0, 1, 2,
+*     etc).
+*
+* @see hook_field_widget_form()
+* @see hook_field_widget_form_alter()
+*/
+function hook_field_widget_WIDGET_TYPE_form_alter(&$element, &$form_state, $context) {
+// Code here will only act on widgets of type WIDGET_TYPE.  For example,
+// hook_field_widget_mymodule_autocomplete_form_alter() will only act on
+// widgets of type 'mymodule_autocomplete'.
+$element['#autocomplete_path'] = 'mymodule/autocomplete_path';
+}
+/**
+* Alters the widget properties of a field instance before it gets displayed.
+*
+* Note that instead of hook_field_widget_properties_alter(), which is called
+* for all fields on all entity types,
+* hook_field_widget_properties_ENTITY_TYPE_alter() may be used to alter widget
+* properties for fields on a specific entity type only.
+*
+* This hook is called once per field per added or edit entity. If the result
+* of the hook involves reading from the database, it is highly recommended to
+* statically cache the information.
+*
+* @param $widget
+*   The instance's widget properties.
+* @param $context
+*   An associative array containing:
+*   - entity_type: The entity type; e.g., 'node' or 'user'.
+*   - entity: The entity object.
+*   - field: The field that the widget belongs to.
+*   - instance: The instance of the field.
+*
+* @see hook_field_widget_properties_ENTITY_TYPE_alter()
+*/
+function hook_field_widget_properties_alter(&$widget, $context) {
+// Change a widget's type according to the time of day.
+$field = $context['field'];
+if ($context['entity_type'] == 'node' && $field['field_name'] == 'field_foo') {
+$time = date('H');
+$widget['type'] = $time < 12 ? 'widget_am' : 'widget_pm';
+}
+}
+/**
+* Flag a field-level validation error.
+*
+* @param $element
+*   An array containing the form element for the widget. The error needs to be
+*   flagged on the right sub-element, according to the widget's internal
+*   structure.
+* @param $error
+*   An associative array with the following key-value pairs, as returned by
+*   hook_field_validate():
+*   - error: the error code. Complex widgets might need to report different
+*     errors to different form elements inside the widget.
+*   - message: the human readable message to be displayed.
+* @param $form
+*   The form structure where field elements are attached to. This might be a
+*   full form structure, or a sub-element of a larger form.
+* @param $form_state
+*   An associative array containing the current state of the form.
+*/
+function hook_field_widget_error($element, $error, $form, &$form_state) {
+form_error($element, $error['message']);
+}
+/**
+* @} End of "defgroup field_widget".
+*/
+/**
+* @defgroup field_formatter Field Formatter API
+* @{
+* Define Field API formatter types.
+*
+* Field API formatters specify how fields are displayed when the entity to
+* which the field is attached is displayed. Fields of a given
+* @link field_types field type @endlink may be displayed using more than one
+* formatter. In this case, the Field UI module allows the site builder to
+* choose which formatter to use. Field formatters are defined by implementing
+* hook_field_formatter_info().
+*
+* @see field
+* @see field_types
+* @see field_widget
+*/
+/**
+* Expose Field API formatter types.
+*
+* Formatters handle the display of field values. Formatter hooks are typically
+* called by the Field Attach API field_attach_prepare_view() and
+* field_attach_view() functions.
+*
+* @return
+*   An array describing the formatter types implemented by the module.
+*   The keys are formatter type names. To avoid name clashes, formatter type
+*   names should be prefixed with the name of the module that exposes them.
+*   The values are arrays describing the formatter type, with the following
+*   key/value pairs:
+*   - label: The human-readable name of the formatter type.
+*   - description: A short description for the formatter type.
+*   - field types: An array of field types the formatter supports.
+*   - settings: An array whose keys are the names of the settings available
+*     for the formatter type, and whose values are the default values for
+*     those settings.
+*
+* @see hook_field_formatter_info_alter()
+* @see hook_field_formatter_view()
+* @see hook_field_formatter_prepare_view()
+*/
+function hook_field_formatter_info() {
+return array(
+'text_default' => array(
+'label' => t('Default'),
+'field types' => array('text', 'text_long', 'text_with_summary'),
+),
+'text_plain' => array(
+'label' => t('Plain text'),
+'field types' => array('text', 'text_long', 'text_with_summary'),
+),
+// The text_trimmed formatter displays the trimmed version of the
+// full element of the field. It is intended to be used with text
+// and text_long fields. It also works with text_with_summary
+// fields though the text_summary_or_trimmed formatter makes more
+// sense for that field type.
+'text_trimmed' => array(
+'label' => t('Trimmed'),
+'field types' => array('text', 'text_long', 'text_with_summary'),
+),
+// The 'summary or trimmed' field formatter for text_with_summary
+// fields displays returns the summary element of the field or, if
+// the summary is empty, the trimmed version of the full element
+// of the field.
+'text_summary_or_trimmed' => array(
+'label' => t('Summary or trimmed'),
+'field types' => array('text_with_summary'),
+),
+);
+}
+/**
+* Perform alterations on Field API formatter types.
+*
+* @param $info
+*   An array of information on formatter types exposed by
+*   hook_field_formatter_info() implementations.
+*/
+function hook_field_formatter_info_alter(&$info) {
+// Add a setting to a formatter type.
+$info['text_default']['settings'] += array(
+'mymodule_additional_setting' => 'default value',
+);
+// Let a new field type re-use an existing formatter.
+$info['text_default']['field types'][] = 'my_field_type';
+}
+/**
+* Allow formatters to load information for field values being displayed.
+*
+* This should be used when a formatter needs to load additional information
+* from the database in order to render a field, for example a reference field
+* which displays properties of the referenced entities such as name or type.
+*
+* This hook is called after the field type's own hook_field_prepare_view().
+*
+* Unlike most other field hooks, this hook operates on multiple entities. The
+* $entities, $instances and $items parameters are arrays keyed by entity ID.
+* For performance reasons, information for all available entities should be
+* loaded in a single query where possible.
+*
+* @param $entity_type
+*   The type of $entity.
+* @param $entities
+*   Array of entities being displayed, keyed by entity ID.
+* @param $field
+*   The field structure for the operation.
+* @param $instances
+*   Array of instance structures for $field for each entity, keyed by entity
+*   ID.
+* @param $langcode
+*   The language the field values are to be shown in. If no language is
+*   provided the current language is used.
+* @param $items
+*   Array of field values for the entities, keyed by entity ID.
+* @param $displays
+*   Array of display settings to use for each entity, keyed by entity ID.
+*
+* @return
+*   Changes or additions to field values are done by altering the $items
+*   parameter by reference.
+*/
+function hook_field_formatter_prepare_view($entity_type, $entities, $field, $instances, $langcode, &$items, $displays) {
+$tids = array();
+// Collect every possible term attached to any of the fieldable entities.
+foreach ($entities as $id => $entity) {
+foreach ($items[$id] as $delta => $item) {
+// Force the array key to prevent duplicates.
+$tids[$item['tid']] = $item['tid'];
+}
+}
+if ($tids) {
+$terms = taxonomy_term_load_multiple($tids);
+// Iterate through the fieldable entities again to attach the loaded term
+// data.
+foreach ($entities as $id => $entity) {
+$rekey = FALSE;
+foreach ($items[$id] as $delta => $item) {
+// Check whether the taxonomy term field instance value could be loaded.
+if (isset($terms[$item['tid']])) {
+// Replace the instance value with the term data.
+$items[$id][$delta]['taxonomy_term'] = $terms[$item['tid']];
+}
+// Otherwise, unset the instance value, since the term does not exist.
+else {
+unset($items[$id][$delta]);
+$rekey = TRUE;
+}
+}
+if ($rekey) {
+// Rekey the items array.
+$items[$id] = array_values($items[$id]);
+}
+}
+}
+}
+/**
+* Build a renderable array for a field value.
+*
+* @param $entity_type
+*   The type of $entity.
+* @param $entity
+*   The entity being displayed.
+* @param $field
+*   The field structure.
+* @param $instance
+*   The field instance.
+* @param $langcode
+*   The language associated with $items.
+* @param $items
+*   Array of values for this field.
+* @param $display
+*   The display settings to use, as found in the 'display' entry of instance
+*   definitions. The array notably contains the following keys and values;
+*   - type: The name of the formatter to use.
+*   - settings: The array of formatter settings.
+*
+* @return
+*   A renderable array for the $items, as an array of child elements keyed
+*   by numeric indexes starting from 0.
+*/
+function hook_field_formatter_view($entity_type, $entity, $field, $instance, $langcode, $items, $display) {
+$element = array();
+$settings = $display['settings'];
+switch ($display['type']) {
+case 'sample_field_formatter_simple':
+// Common case: each value is displayed individually in a sub-element
+// keyed by delta. The field.tpl.php template specifies the markup
+// wrapping each value.
+foreach ($items as $delta => $item) {
+$element[$delta] = array('#markup' => $settings['some_setting'] . $item['value']);
+}
+break;
+case 'sample_field_formatter_themeable':
+// More elaborate formatters can defer to a theme function for easier
+// customization.
+foreach ($items as $delta => $item) {
+$element[$delta] = array(
+'#theme' => 'mymodule_theme_sample_field_formatter_themeable',
+'#data' => $item['value'],
+'#some_setting' => $settings['some_setting'],
+);
+}
+break;
+case 'sample_field_formatter_combined':
+// Some formatters might need to display all values within a single piece
+// of markup.
+$rows = array();
+foreach ($items as $delta => $item) {
+$rows[] = array($delta, $item['value']);
+}
+$element[0] = array(
+'#theme' => 'table',
+'#header' => array(t('Delta'), t('Value')),
+'#rows' => $rows,
+);
+break;
+}
+return $element;
+}
+/**
+* @} End of "defgroup field_formatter".
+*/
+/**
+* @addtogroup field_attach
+* @{
+*/
+/**
+* Act on field_attach_form().
+*
+* This hook is invoked after the field module has performed the operation.
+* Implementing modules should alter the $form or $form_state parameters.
+*
+* @param $entity_type
+*   The type of $entity; for example, 'node' or 'user'.
+* @param $entity
+*   The entity for which an edit form is being built.
+* @param $form
+*   The form structure where field elements are attached to. This might be a
+*   full form structure, or a sub-element of a larger form. The
+*   $form['#parents'] property can be used to identify the corresponding part
+*   of $form_state['values']. Hook implementations that need to act on the
+*   top-level properties of the global form (like #submit, #validate...) can
+*   add a #process callback to the array received in the $form parameter, and
+*   act on the $complete_form parameter in the process callback.
+* @param $form_state
+*   An associative array containing the current state of the form.
+* @param $langcode
+*   The language the field values are going to be entered in. If no language
+*   is provided the default site language will be used.
+*/
+function hook_field_attach_form($entity_type, $entity, &$form, &$form_state, $langcode) {
+// Add a checkbox allowing a given field to be emptied.
+// See hook_field_attach_submit() for the corresponding processing code.
+$form['empty_field_foo'] = array(
+'#type' => 'checkbox',
+'#title' => t("Empty the 'field_foo' field"),
+);
+}
+/**
+* Act on field_attach_load().
+*
+* This hook is invoked after the field module has performed the operation.
+*
+* Unlike other field_attach hooks, this hook accounts for 'multiple loads'.
+* Instead of the usual $entity parameter, it accepts an array of entities,
+* indexed by entity ID. For performance reasons, information for all available
+* entities should be loaded in a single query where possible.
+*
+* The changes made to the entities' field values get cached by the field cache
+* for subsequent loads.
+*
+* See field_attach_load() for details and arguments.
+*/
+function hook_field_attach_load($entity_type, $entities, $age, $options) {
+// @todo Needs function body.
+}
+/**
+* Act on field_attach_validate().
+*
+* This hook is invoked after the field module has performed the operation.
+*
+* See field_attach_validate() for details and arguments.
+*
+* @param $entity_type
+*   The type of $entity; e.g., 'node' or 'user'.
+* @param $entity
+*   The entity with fields to validate.
+* @param array $errors
+*   The array of errors (keyed by field name, language code, and delta) that
+*   have already been reported for the entity. The function should add its
+*   errors to this array. Each error is an associative array with the following
+*   keys and values:
+*   - error: An error code (should be a string prefixed with the module name).
+*   - message: The human readable message to be displayed.
+*/
+function hook_field_attach_validate($entity_type, $entity, &$errors) {
+// Make sure any images in article nodes have an alt text.
+if ($entity_type == 'node' && $entity->type == 'article' && !empty($entity->field_image)) {
+foreach ($entity->field_image as $langcode => $items) {
+foreach ($items as $delta => $item) {
+if (!empty($item['fid']) && empty($item['alt'])) {
+$errors['field_image'][$langcode][$delta][] = array(
+'error' => 'field_example_invalid',
+'message' => t('All images in articles need to have an alternative text set.'),
+);
+}
+}
+}
+}
+}
+/**
+* Act on field_attach_submit().
+*
+* This hook is invoked after the field module has performed the operation.
+*
+* @param $entity_type
+*   The type of $entity; for example, 'node' or 'user'.
+* @param $entity
+*   The entity for which an edit form is being submitted. The incoming form
+*   values have been extracted as field values of the $entity object.
+* @param $form
+*   The form structure where field elements are attached to. This might be a
+*   full form structure, or a sub-part of a larger form. The $form['#parents']
+*   property can be used to identify the corresponding part of
+*   $form_state['values'].
+* @param $form_state
+*   An associative array containing the current state of the form.
+*/
+function hook_field_attach_submit($entity_type, $entity, $form, &$form_state) {
+// Sample case of an 'Empty the field' checkbox added on the form, allowing
+// a given field to be emptied.
+$values = drupal_array_get_nested_value($form_state['values'], $form['#parents']);
+if (!empty($values['empty_field_foo'])) {
+unset($entity->field_foo);
+}
+}
+/**
+* Act on field_attach_presave().
+*
+* This hook is invoked after the field module has performed the operation.
+*
+* See field_attach_presave() for details and arguments.
+*/
+function hook_field_attach_presave($entity_type, $entity) {
+// @todo Needs function body.
+}
+/**
+* Act on field_attach_insert().
+*
+* This hook is invoked after the field module has performed the operation.
+*
+* See field_attach_insert() for details and arguments.
+*/
+function hook_field_attach_insert($entity_type, $entity) {
+// @todo Needs function body.
+}
+/**
+* Act on field_attach_update().
+*
+* This hook is invoked after the field module has performed the operation.
+*
+* See field_attach_update() for details and arguments.
+*/
+function hook_field_attach_update($entity_type, $entity) {
+// @todo Needs function body.
+}
+/**
+* Alter field_attach_preprocess() variables.
+*
+* This hook is invoked while preprocessing the field.tpl.php template file
+* in field_attach_preprocess().
+*
+* @param $variables
+*   The variables array is passed by reference and will be populated with field
+*   values.
+* @param $context
+*   An associative array containing:
+*   - entity_type: The type of $entity; for example, 'node' or 'user'.
+*   - entity: The entity with fields to render.
+*   - element: The structured array containing the values ready for rendering.
+*/
+function hook_field_attach_preprocess_alter(&$variables, $context) {
+// @todo Needs function body.
+}
+/**
+* Act on field_attach_delete().
+*
+* This hook is invoked after the field module has performed the operation.
+*
+* See field_attach_delete() for details and arguments.
+*/
+function hook_field_attach_delete($entity_type, $entity) {
+// @todo Needs function body.
+}
+/**
+* Act on field_attach_delete_revision().
+*
+* This hook is invoked after the field module has performed the operation.
+*
+* See field_attach_delete_revision() for details and arguments.
+*/
+function hook_field_attach_delete_revision($entity_type, $entity) {
+// @todo Needs function body.
+}
+/**
+* Act on field_purge_data().
+*
+* This hook is invoked in field_purge_data() and allows modules to act on
+* purging data from a single field pseudo-entity. For example, if a module
+* relates data in the field with its own data, it may purge its own data
+* during this process as well.
+*
+* @param $entity_type
+*   The type of $entity; for example, 'node' or 'user'.
+* @param $entity
+*   The pseudo-entity whose field data is being purged.
+* @param $field
+*   The (possibly deleted) field whose data is being purged.
+* @param $instance
+*   The deleted field instance whose data is being purged.
+*
+* @see @link field_purge Field API bulk data deletion @endlink
+* @see field_purge_data()
+*/
+function hook_field_attach_purge($entity_type, $entity, $field, $instance) {
+// find the corresponding data in mymodule and purge it
+if ($entity_type == 'node' && $field->field_name == 'my_field_name') {
+mymodule_remove_mydata($entity->nid);
+}
+}
+/**
+* Perform alterations on field_attach_view() or field_view_field().
+*
+* This hook is invoked after the field module has performed the operation.
+*
+* @param $output
+*   The structured content array tree for all of the entity's fields.
+* @param $context
+*   An associative array containing:
+*   - entity_type: The type of $entity; for example, 'node' or 'user'.
+*   - entity: The entity with fields to render.
+*   - view_mode: View mode; for example, 'full' or 'teaser'.
+*   - display: Either a view mode string or an array of display settings. If
+*     this hook is being invoked from field_attach_view(), the 'display'
+*     element is set to the view mode string. If this hook is being invoked
+*     from field_view_field(), this element is set to the $display argument
+*     and the view_mode element is set to '_custom'. See field_view_field()
+*     for more information on what its $display argument contains.
+*   - language: The language code used for rendering.
+*/
+function hook_field_attach_view_alter(&$output, $context) {
+// Append RDF term mappings on displayed taxonomy links.
+foreach (element_children($output) as $field_name) {
+$element = &$output[$field_name];
+if ($element['#field_type'] == 'taxonomy_term_reference' && $element['#formatter'] == 'taxonomy_term_reference_link') {
+foreach ($element['#items'] as $delta => $item) {
+$term = $item['taxonomy_term'];
+if (!empty($term->rdf_mapping['rdftype'])) {
+$element[$delta]['#options']['attributes']['typeof'] = $term->rdf_mapping['rdftype'];
+}
+if (!empty($term->rdf_mapping['name']['predicates'])) {
+$element[$delta]['#options']['attributes']['property'] = $term->rdf_mapping['name']['predicates'];
+}
+}
+}
+}
+}
+/**
+* Perform alterations on field_attach_prepare_translation().
+*
+* This hook is invoked after the field module has performed the operation.
+*
+* @param $entity
+*   The entity being prepared for translation.
+* @param $context
+*   An associative array containing:
+*   - entity_type: The type of $entity; e.g. 'node' or 'user'.
+*   - langcode: The language the entity has to be translated in.
+*   - source_entity: The entity holding the field values to be translated.
+*   - source_langcode: The source language from which translate.
+*/
+function hook_field_attach_prepare_translation_alter(&$entity, $context) {
+if ($context['entity_type'] == 'custom_entity_type') {
+$entity->custom_field = $context['source_entity']->custom_field;
+}
+}
+/**
+* Perform alterations on field_language() values.
+*
+* This hook is invoked to alter the array of display languages for the given
+* entity.
+*
+* @param $display_language
+*   A reference to an array of language codes keyed by field name.
+* @param $context
+*   An associative array containing:
+*   - entity_type: The type of the entity to be displayed.
+*   - entity: The entity with fields to render.
+*   - langcode: The language code $entity has to be displayed in.
+*
+* @ingroup field_language
+*/
+function hook_field_language_alter(&$display_language, $context) {
+// Do not apply core language fallback rules if they are disabled or if Locale
+// is not registered as a translation handler.
+if (variable_get('locale_field_language_fallback', TRUE) && field_has_translation_handler($context['entity_type'], 'locale')) {
+locale_field_language_fallback($display_language, $context['entity'], $context['language']);
+}
+}
+/**
+* Alter field_available_languages() values.
+*
+* This hook is invoked from field_available_languages() to allow modules to
+* alter the array of available languages for the given field.
+*
+* @param $languages
+*   A reference to an array of language codes to be made available.
+* @param $context
+*   An associative array containing:
+*   - entity_type: The type of the entity the field is attached to.
+*   - field: A field data structure.
+*
+* @ingroup field_language
+*/
+function hook_field_available_languages_alter(&$languages, $context) {
+// Add an unavailable language.
+$languages[] = 'xx';
+// Remove an available language.
+$index = array_search('yy', $languages);
+unset($languages[$index]);
+}
+/**
+* Act on field_attach_create_bundle().
+*
+* This hook is invoked after the field module has performed the operation.
+*
+* See field_attach_create_bundle() for details and arguments.
+*/
+function hook_field_attach_create_bundle($entity_type, $bundle) {
+// When a new bundle is created, the menu needs to be rebuilt to add the
+// Field UI menu item tabs.
+variable_set('menu_rebuild_needed', TRUE);
+}
+/**
+* Act on field_attach_rename_bundle().
+*
+* This hook is invoked after the field module has performed the operation.
+*
+* See field_attach_rename_bundle() for details and arguments.
+*/
+function hook_field_attach_rename_bundle($entity_type, $bundle_old, $bundle_new) {
+// Update the extra weights variable with new information.
+if ($bundle_old !== $bundle_new) {
+$extra_weights = variable_get('field_extra_weights', array());
+if (isset($info[$entity_type][$bundle_old])) {
+$extra_weights[$entity_type][$bundle_new] = $extra_weights[$entity_type][$bundle_old];
+unset($extra_weights[$entity_type][$bundle_old]);
+variable_set('field_extra_weights', $extra_weights);
+}
+}
+}
+/**
+* Act on field_attach_delete_bundle.
+*
+* This hook is invoked after the field module has performed the operation.
+*
+* @param $entity_type
+*   The type of entity; for example, 'node' or 'user'.
+* @param $bundle
+*   The name of the bundle that was just deleted.
+* @param $instances
+*   An array of all instances that existed for the bundle before it was
+*   deleted.
+*/
+function hook_field_attach_delete_bundle($entity_type, $bundle, $instances) {
+// Remove the extra weights variable information for this bundle.
+$extra_weights = variable_get('field_extra_weights', array());
+if (isset($extra_weights[$entity_type][$bundle])) {
+unset($extra_weights[$entity_type][$bundle]);
+variable_set('field_extra_weights', $extra_weights);
+}
+}
+/**
+* @} End of "addtogroup field_attach".
+*/
+/**
+* @addtogroup field_storage
+* @{
+*/
+/**
+* Expose Field API storage backends.
+*
+* @return
+*   An array describing the storage backends implemented by the module.
+*   The keys are storage backend names. To avoid name clashes, storage backend
+*   names should be prefixed with the name of the module that exposes them.
+*   The values are arrays describing the storage backend, with the following
+*   key/value pairs:
+*   - label: The human-readable name of the storage backend.
+*   - description: A short description for the storage backend.
+*   - settings: An array whose keys are the names of the settings available
+*     for the storage backend, and whose values are the default values for
+*     those settings.
+*/
+function hook_field_storage_info() {
+return array(
+'field_sql_storage' => array(
+'label' => t('Default SQL storage'),
+'description' => t('Stores fields in the local SQL database, using per-field tables.'),
+'settings' => array(),
+),
+);
+}
+/**
+* Perform alterations on Field API storage types.
+*
+* @param $info
+*   Array of informations on storage types exposed by
+*   hook_field_field_storage_info() implementations.
+*/
+function hook_field_storage_info_alter(&$info) {
+// Add a setting to a storage type.
+$info['field_sql_storage']['settings'] += array(
+'mymodule_additional_setting' => 'default value',
+);
+}
+/**
+* Reveal the internal details about the storage for a field.
+*
+* For example, an SQL storage module might return the Schema API structure for
+* the table. A key/value storage module might return the server name,
+* authentication credentials, and bin name.
+*
+* Field storage modules are not obligated to implement this hook. Modules
+* that rely on these details must only use them for read operations.
+*
+* @param $field
+*   A field structure.
+*
+* @return
+*   An array of details.
+*    - The first dimension is a store type (sql, solr, etc).
+*    - The second dimension indicates the age of the values in the store
+*      FIELD_LOAD_CURRENT or FIELD_LOAD_REVISION.
+*    - Other dimensions are specific to the field storage module.
+*
+* @see hook_field_storage_details_alter()
+*/
+function hook_field_storage_details($field) {
+$details = array();
+// Add field columns.
+foreach ((array) $field['columns'] as $column_name => $attributes) {
+$real_name = _field_sql_storage_columnname($field['field_name'], $column_name);
+$columns[$column_name] = $real_name;
+}
+return array(
+'sql' => array(
+FIELD_LOAD_CURRENT => array(
+_field_sql_storage_tablename($field) => $columns,
+),
+FIELD_LOAD_REVISION => array(
+_field_sql_storage_revision_tablename($field) => $columns,
+),
+),
+);
+}
+/**
+* Perform alterations on Field API storage details.
+*
+* @param $details
+*   An array of storage details for fields as exposed by
+*   hook_field_storage_details() implementations.
+* @param $field
+*   A field structure.
+*
+* @see hook_field_storage_details()
+*/
+function hook_field_storage_details_alter(&$details, $field) {
+if ($field['field_name'] == 'field_of_interest') {
+$columns = array();
+foreach ((array) $field['columns'] as $column_name => $attributes) {
+$columns[$column_name] = $column_name;
+}
+$details['drupal_variables'] = array(
+FIELD_LOAD_CURRENT => array(
+'moon' => $columns,
+),
+FIELD_LOAD_REVISION => array(
+'mars' => $columns,
+),
+);
+}
+}
+/**
+* Load field data for a set of entities.
+*
+* This hook is invoked from field_attach_load() to ask the field storage
+* module to load field data.
+*
+* Modules implementing this hook should load field values and add them to
+* objects in $entities. Fields with no values should be added as empty
+* arrays.
+*
+* @param $entity_type
+*   The type of entity, such as 'node' or 'user'.
+* @param $entities
+*   The array of entity objects to add fields to, keyed by entity ID.
+* @param $age
+*   FIELD_LOAD_CURRENT to load the most recent revision for all fields, or
+*   FIELD_LOAD_REVISION to load the version indicated by each entity.
+* @param $fields
+*   An array listing the fields to be loaded. The keys of the array are field
+*   IDs, and the values of the array are the entity IDs (or revision IDs,
+*   depending on the $age parameter) to add each field to.
+* @param $options
+*   An associative array of additional options, with the following keys:
+*   - deleted: If TRUE, deleted fields should be loaded as well as
+*     non-deleted fields. If unset or FALSE, only non-deleted fields should be
+*     loaded.
+*/
+function hook_field_storage_load($entity_type, $entities, $age, $fields, $options) {
+$load_current = $age == FIELD_LOAD_CURRENT;
+foreach ($fields as $field_id => $ids) {
+// By the time this hook runs, the relevant field definitions have been
+// populated and cached in FieldInfo, so calling field_info_field_by_id()
+// on each field individually is more efficient than loading all fields in
+// memory upfront with field_info_field_by_ids().
+$field = field_info_field_by_id($field_id);
+$field_name = $field['field_name'];
+$table = $load_current ? _field_sql_storage_tablename($field) : _field_sql_storage_revision_tablename($field);
+$query = db_select($table, 't')
+->fields('t')
+->condition('entity_type', $entity_type)
+->condition($load_current ? 'entity_id' : 'revision_id', $ids, 'IN')
+->condition('language', field_available_languages($entity_type, $field), 'IN')
+->orderBy('delta');
+if (empty($options['deleted'])) {
+$query->condition('deleted', 0);
+}
+$results = $query->execute();
+$delta_count = array();
+foreach ($results as $row) {
+if (!isset($delta_count[$row->entity_id][$row->language])) {
+$delta_count[$row->entity_id][$row->language] = 0;
+}
+if ($field['cardinality'] == FIELD_CARDINALITY_UNLIMITED || $delta_count[$row->entity_id][$row->language] < $field['cardinality']) {
+$item = array();
+// For each column declared by the field, populate the item
+// from the prefixed database column.
+foreach ($field['columns'] as $column => $attributes) {
+$column_name = _field_sql_storage_columnname($field_name, $column);
+$item[$column] = $row->$column_name;
+}
+// Add the item to the field values for the entity.
+$entities[$row->entity_id]->{$field_name}[$row->language][] = $item;
+$delta_count[$row->entity_id][$row->language]++;
+}
+}
+}
+}
+/**
+* Write field data for an entity.
+*
+* This hook is invoked from field_attach_insert() and field_attach_update(),
+* to ask the field storage module to save field data.
+*
+* @param $entity_type
+*   The entity type of entity, such as 'node' or 'user'.
+* @param $entity
+*   The entity on which to operate.
+* @param $op
+*   FIELD_STORAGE_UPDATE when updating an existing entity,
+*   FIELD_STORAGE_INSERT when inserting a new entity.
+* @param $fields
+*   An array listing the fields to be written. The keys and values of the
+*   array are field IDs.
+*/
+function hook_field_storage_write($entity_type, $entity, $op, $fields) {
+list($id, $vid, $bundle) = entity_extract_ids($entity_type, $entity);
+if (!isset($vid)) {
+$vid = $id;
+}
+foreach ($fields as $field_id) {
+$field = field_info_field_by_id($field_id);
+$field_name = $field['field_name'];
+$table_name = _field_sql_storage_tablename($field);
+$revision_name = _field_sql_storage_revision_tablename($field);
+$all_languages = field_available_languages($entity_type, $field);
+$field_languages = array_intersect($all_languages, array_keys((array) $entity->$field_name));
+// Delete and insert, rather than update, in case a value was added.
+if ($op == FIELD_STORAGE_UPDATE) {
+// Delete languages present in the incoming $entity->$field_name.
+// Delete all languages if $entity->$field_name is empty.
+$languages = !empty($entity->$field_name) ? $field_languages : $all_languages;
+if ($languages) {
+db_delete($table_name)
+->condition('entity_type', $entity_type)
+->condition('entity_id', $id)
+->condition('language', $languages, 'IN')
+->execute();
+db_delete($revision_name)
+->condition('entity_type', $entity_type)
+->condition('entity_id', $id)
+->condition('revision_id', $vid)
+->condition('language', $languages, 'IN')
+->execute();
+}
+}
+// Prepare the multi-insert query.
+$do_insert = FALSE;
+$columns = array('entity_type', 'entity_id', 'revision_id', 'bundle', 'delta', 'language');
+foreach ($field['columns'] as $column => $attributes) {
+$columns[] = _field_sql_storage_columnname($field_name, $column);
+}
+$query = db_insert($table_name)->fields($columns);
+$revision_query = db_insert($revision_name)->fields($columns);
+foreach ($field_languages as $langcode) {
+$items = (array) $entity->{$field_name}[$langcode];
+$delta_count = 0;
+foreach ($items as $delta => $item) {
+// We now know we have something to insert.
+$do_insert = TRUE;
+$record = array(
+'entity_type' => $entity_type,
+'entity_id' => $id,
+'revision_id' => $vid,
+'bundle' => $bundle,
+'delta' => $delta,
+'language' => $langcode,
+);
+foreach ($field['columns'] as $column => $attributes) {
+$record[_field_sql_storage_columnname($field_name, $column)] = isset($item[$column]) ? $item[$column] : NULL;
+}
+$query->values($record);
+if (isset($vid)) {
+$revision_query->values($record);
+}
+if ($field['cardinality'] != FIELD_CARDINALITY_UNLIMITED && ++$delta_count == $field['cardinality']) {
+break;
+}
+}
+}
+// Execute the query if we have values to insert.
+if ($do_insert) {
+$query->execute();
+$revision_query->execute();
+}
+}
+}
+/**
+* Delete all field data for an entity.
+*
+* This hook is invoked from field_attach_delete() to ask the field storage
+* module to delete field data.
+*
+* @param $entity_type
+*   The entity type of entity, such as 'node' or 'user'.
+* @param $entity
+*   The entity on which to operate.
+* @param $fields
+*   An array listing the fields to delete. The keys and values of the
+*   array are field IDs.
+*/
+function hook_field_storage_delete($entity_type, $entity, $fields) {
+list($id, $vid, $bundle) = entity_extract_ids($entity_type, $entity);
+foreach (field_info_instances($entity_type, $bundle) as $instance) {
+if (isset($fields[$instance['field_id']])) {
+$field = field_info_field_by_id($instance['field_id']);
+field_sql_storage_field_storage_purge($entity_type, $entity, $field, $instance);
+}
+}
+}
+/**
+* Delete a single revision of field data for an entity.
+*
+* This hook is invoked from field_attach_delete_revision() to ask the field
+* storage module to delete field revision data.
+*
+* Deleting the current (most recently written) revision is not
+* allowed as has undefined results.
+*
+* @param $entity_type
+*   The entity type of entity, such as 'node' or 'user'.
+* @param $entity
+*   The entity on which to operate. The revision to delete is
+*   indicated by the entity's revision ID property, as identified by
+*   hook_fieldable_info() for $entity_type.
+* @param $fields
+*   An array listing the fields to delete. The keys and values of the
+*   array are field IDs.
+*/
+function hook_field_storage_delete_revision($entity_type, $entity, $fields) {
+list($id, $vid, $bundle) = entity_extract_ids($entity_type, $entity);
+if (isset($vid)) {
+foreach ($fields as $field_id) {
+$field = field_info_field_by_id($field_id);
+$revision_name = _field_sql_storage_revision_tablename($field);
+db_delete($revision_name)
+->condition('entity_type', $entity_type)
+->condition('entity_id', $id)
+->condition('revision_id', $vid)
+->execute();
+}
+}
+}
+/**
+* Execute an EntityFieldQuery.
+*
+* This hook is called to find the entities having certain entity and field
+* conditions and sort them in the given field order. If the field storage
+* engine also handles property sorts and orders, it should unset those
+* properties in the called object to signal that those have been handled.
+*
+* @param EntityFieldQuery $query
+*   An EntityFieldQuery.
+*
+* @return
+*   See EntityFieldQuery::execute() for the return values.
+*/
+function hook_field_storage_query($query) {
+$groups = array();
+if ($query->age == FIELD_LOAD_CURRENT) {
+$tablename_function = '_field_sql_storage_tablename';
+$id_key = 'entity_id';
+}
+else {
+$tablename_function = '_field_sql_storage_revision_tablename';
+$id_key = 'revision_id';
+}
+$table_aliases = array();
+// Add tables for the fields used.
+foreach ($query->fields as $key => $field) {
+$tablename = $tablename_function($field);
+// Every field needs a new table.
+$table_alias = $tablename . $key;
+$table_aliases[$key] = $table_alias;
+if ($key) {
+$select_query->join($tablename, $table_alias, "$table_alias.entity_type = $field_base_table.entity_type AND $table_alias.$id_key = $field_base_table.$id_key");
+}
+else {
+$select_query = db_select($tablename, $table_alias);
+$select_query->addTag('entity_field_access');
+$select_query->addMetaData('base_table', $tablename);
+$select_query->fields($table_alias, array('entity_type', 'entity_id', 'revision_id', 'bundle'));
+$field_base_table = $table_alias;
+}
+if ($field['cardinality'] != 1) {
+$select_query->distinct();
+}
+}
+// Add field conditions.
+foreach ($query->fieldConditions as $key => $condition) {
+$table_alias = $table_aliases[$key];
+$field = $condition['field'];
+// Add the specified condition.
+$sql_field = "$table_alias." . _field_sql_storage_columnname($field['field_name'], $condition['column']);
+$query->addCondition($select_query, $sql_field, $condition);
+// Add delta / language group conditions.
+foreach (array('delta', 'language') as $column) {
+if (isset($condition[$column . '_group'])) {
+$group_name = $condition[$column . '_group'];
+if (!isset($groups[$column][$group_name])) {
+$groups[$column][$group_name] = $table_alias;
+}
+else {
+$select_query->where("$table_alias.$column = " . $groups[$column][$group_name] . ".$column");
+}
+}
+}
+}
+if (isset($query->deleted)) {
+$select_query->condition("$field_base_table.deleted", (int) $query->deleted);
+}
+// Is there a need to sort the query by property?
+$has_property_order = FALSE;
+foreach ($query->order as $order) {
+if ($order['type'] == 'property') {
+$has_property_order = TRUE;
+}
+}
+if ($query->propertyConditions || $has_property_order) {
+if (empty($query->entityConditions['entity_type']['value'])) {
+throw new EntityFieldQueryException('Property conditions and orders must have an entity type defined.');
+}
+$entity_type = $query->entityConditions['entity_type']['value'];
+$entity_base_table = _field_sql_storage_query_join_entity($select_query, $entity_type, $field_base_table);
+$query->entityConditions['entity_type']['operator'] = '=';
+foreach ($query->propertyConditions as $property_condition) {
+$query->addCondition($select_query, "$entity_base_table." . $property_condition['column'], $property_condition);
+}
+}
+foreach ($query->entityConditions as $key => $condition) {
+$query->addCondition($select_query, "$field_base_table.$key", $condition);
+}
+// Order the query.
+foreach ($query->order as $order) {
+if ($order['type'] == 'entity') {
+$key = $order['specifier'];
+$select_query->orderBy("$field_base_table.$key", $order['direction']);
+}
+elseif ($order['type'] == 'field') {
+$specifier = $order['specifier'];
+$field = $specifier['field'];
+$table_alias = $table_aliases[$specifier['index']];
+$sql_field = "$table_alias." . _field_sql_storage_columnname($field['field_name'], $specifier['column']);
+$select_query->orderBy($sql_field, $order['direction']);
+}
+elseif ($order['type'] == 'property') {
+$select_query->orderBy("$entity_base_table." . $order['specifier'], $order['direction']);
+}
+}
+return $query->finishQuery($select_query, $id_key);
+}
+/**
+* Act on creation of a new field.
+*
+* This hook is invoked from field_create_field() to ask the field storage
+* module to save field information and prepare for storing field instances.
+* If there is a problem, the field storage module should throw an exception.
+*
+* @param $field
+*   The field structure being created.
+*/
+function hook_field_storage_create_field($field) {
+$schema = _field_sql_storage_schema($field);
+foreach ($schema as $name => $table) {
+db_create_table($name, $table);
+}
+drupal_get_schema(NULL, TRUE);
+}
+/**
+* Act on deletion of a field.
+*
+* This hook is invoked from field_delete_field() to ask the field storage
+* module to mark all information stored in the field for deletion.
+*
+* @param $field
+*   The field being deleted.
+*/
+function hook_field_storage_delete_field($field) {
+// Mark all data associated with the field for deletion.
+$field['deleted'] = 0;
+$table = _field_sql_storage_tablename($field);
+$revision_table = _field_sql_storage_revision_tablename($field);
+db_update($table)
+->fields(array('deleted' => 1))
+->execute();
+// Move the table to a unique name while the table contents are being deleted.
+$field['deleted'] = 1;
+$new_table = _field_sql_storage_tablename($field);
+$revision_new_table = _field_sql_storage_revision_tablename($field);
+db_rename_table($table, $new_table);
+db_rename_table($revision_table, $revision_new_table);
+drupal_get_schema(NULL, TRUE);
+}
+/**
+* Act on deletion of a field instance.
+*
+* This hook is invoked from field_delete_instance() to ask the field storage
+* module to mark all information stored for the field instance for deletion.
+*
+* @param $instance
+*   The instance being deleted.
+*/
+function hook_field_storage_delete_instance($instance) {
+$field = field_info_field($instance['field_name']);
+$table_name = _field_sql_storage_tablename($field);
+$revision_name = _field_sql_storage_revision_tablename($field);
+db_update($table_name)
+->fields(array('deleted' => 1))
+->condition('entity_type', $instance['entity_type'])
+->condition('bundle', $instance['bundle'])
+->execute();
+db_update($revision_name)
+->fields(array('deleted' => 1))
+->condition('entity_type', $instance['entity_type'])
+->condition('bundle', $instance['bundle'])
+->execute();
+}
+/**
+* Act before the storage backends load field data.
+*
+* This hook allows modules to load data before the Field Storage API,
+* optionally preventing the field storage module from doing so.
+*
+* This lets 3rd party modules override, mirror, shard, or otherwise store a
+* subset of fields in a different way than the current storage engine.
+* Possible use cases include per-bundle storage, per-combo-field storage, etc.
+*
+* Modules implementing this hook should load field values and add them to
+* objects in $entities. Fields with no values should be added as empty
+* arrays. In addition, fields loaded should be added as keys to $skip_fields.
+*
+* @param $entity_type
+*   The type of entity, such as 'node' or 'user'.
+* @param $entities
+*   The array of entity objects to add fields to, keyed by entity ID.
+* @param $age
+*   FIELD_LOAD_CURRENT to load the most recent revision for all fields, or
+*   FIELD_LOAD_REVISION to load the version indicated by each entity.
+* @param $skip_fields
+*   An array keyed by field IDs whose data has already been loaded and
+*   therefore should not be loaded again. Add a key to this array to indicate
+*   that your module has already loaded a field.
+* @param $options
+*   An associative array of additional options, with the following keys:
+*   - field_id: The field ID that should be loaded. If unset, all fields
+*     should be loaded.
+*   - deleted: If TRUE, deleted fields should be loaded as well as
+*     non-deleted fields. If unset or FALSE, only non-deleted fields should be
+*     loaded.
+*/
+function hook_field_storage_pre_load($entity_type, $entities, $age, &$skip_fields, $options) {
+// @todo Needs function body.
+}
+/**
+* Act before the storage backends insert field data.
+*
+* This hook allows modules to store data before the Field Storage API,
+* optionally preventing the field storage module from doing so.
+*
+* @param $entity_type
+*   The type of $entity; for example, 'node' or 'user'.
+* @param $entity
+*   The entity with fields to save.
+* @param $skip_fields
+*   An array keyed by field IDs whose data has already been written and
+*   therefore should not be written again. The values associated with these
+*   keys are not specified.
+* @return
+*   Saved field IDs are set set as keys in $skip_fields.
+*/
+function hook_field_storage_pre_insert($entity_type, $entity, &$skip_fields) {
+if ($entity_type == 'node' && $entity->status && _forum_node_check_node_type($entity)) {
+$query = db_insert('forum_index')->fields(array('nid', 'title', 'tid', 'sticky', 'created', 'comment_count', 'last_comment_timestamp'));
+foreach ($entity->taxonomy_forums as $language) {
+foreach ($language as $delta) {
+$query->values(array(
+'nid' => $entity->nid,
+'title' => $entity->title,
+'tid' => $delta['value'],
+'sticky' => $entity->sticky,
+'created' => $entity->created,
+'comment_count' => 0,
+'last_comment_timestamp' => $entity->created,
+));
+}
+}
+$query->execute();
+}
+}
+/**
+* Act before the storage backends update field data.
+*
+* This hook allows modules to store data before the Field Storage API,
+* optionally preventing the field storage module from doing so.
+*
+* @param $entity_type
+*   The type of $entity; for example, 'node' or 'user'.
+* @param $entity
+*   The entity with fields to save.
+* @param $skip_fields
+*   An array keyed by field IDs whose data has already been written and
+*   therefore should not be written again. The values associated with these
+*   keys are not specified.
+* @return
+*   Saved field IDs are set set as keys in $skip_fields.
+*/
+function hook_field_storage_pre_update($entity_type, $entity, &$skip_fields) {
+$first_call = &drupal_static(__FUNCTION__, array());
+if ($entity_type == 'node' && $entity->status && _forum_node_check_node_type($entity)) {
+// We don't maintain data for old revisions, so clear all previous values
+// from the table. Since this hook runs once per field, per entity, make
+// sure we only wipe values once.
+if (!isset($first_call[$entity->nid])) {
+$first_call[$entity->nid] = FALSE;
+db_delete('forum_index')->condition('nid', $entity->nid)->execute();
+}
+// Only save data to the table if the node is published.
+if ($entity->status) {
+$query = db_insert('forum_index')->fields(array('nid', 'title', 'tid', 'sticky', 'created', 'comment_count', 'last_comment_timestamp'));
+foreach ($entity->taxonomy_forums as $language) {
+foreach ($language as $delta) {
+$query->values(array(
+'nid' => $entity->nid,
+'title' => $entity->title,
+'tid' => $delta['value'],
+'sticky' => $entity->sticky,
+'created' => $entity->created,
+'comment_count' => 0,
+'last_comment_timestamp' => $entity->created,
+));
+}
+}
+$query->execute();
+// The logic for determining last_comment_count is fairly complex, so
+// call _forum_update_forum_index() too.
+_forum_update_forum_index($entity->nid);
+}
+}
+}
+/**
+* @} End of "addtogroup field_storage
+*/
+/**
+* Returns the maximum weight for the entity components handled by the module.
+*
+* Field API takes care of fields and 'extra_fields'. This hook is intended for
+* third-party modules adding other entity components (e.g. field_group).
+*
+* @param $entity_type
+*   The type of entity; e.g. 'node' or 'user'.
+* @param $bundle
+*   The bundle name.
+* @param $context
+*   The context for which the maximum weight is requested. Either 'form', or
+*   the name of a view mode.
+*
+* @return
+*   The maximum weight of the entity's components, or NULL if no components
+*   were found.
+*
+* @ingroup field_info
+*/
+function hook_field_info_max_weight($entity_type, $bundle, $context) {
+$weights = array();
+foreach (my_module_entity_additions($entity_type, $bundle, $context) as $addition) {
+$weights[] = $addition['weight'];
+}
+return $weights ? max($weights) : NULL;
+}
+/**
+* @addtogroup field_types
+* @{
+*/
+/**
+* Alters the display settings of a field before it gets displayed.
+*
+* Note that instead of hook_field_display_alter(), which is called for all
+* fields on all entity types, hook_field_display_ENTITY_TYPE_alter() may be
+* used to alter display settings for fields on a specific entity type only.
+*
+* This hook is called once per field per displayed entity. If the result of the
+* hook involves reading from the database, it is highly recommended to
+* statically cache the information.
+*
+* @param $display
+*   The display settings that will be used to display the field values, as
+*   found in the 'display' key of $instance definitions.
+* @param $context
+*   An associative array containing:
+*   - entity_type: The entity type; e.g., 'node' or 'user'.
+*   - field: The field being rendered.
+*   - instance: The instance being rendered.
+*   - entity: The entity being rendered.
+*   - view_mode: The view mode, e.g. 'full', 'teaser'...
+*
+* @see hook_field_display_ENTITY_TYPE_alter()
+*/
+function hook_field_display_alter(&$display, $context) {
+// Leave field labels out of the search index.
+// Note: The check against $context['entity_type'] == 'node' could be avoided
+// by using hook_field_display_node_alter() instead of
+// hook_field_display_alter(), resulting in less function calls when
+// rendering non-node entities.
+if ($context['entity_type'] == 'node' && $context['view_mode'] == 'search_index') {
+$display['label'] = 'hidden';
+}
+}
+/**
+* Alters the display settings of a field on a given entity type before it gets displayed.
+*
+* Modules can implement hook_field_display_ENTITY_TYPE_alter() to alter display
+* settings for fields on a specific entity type, rather than implementing
+* hook_field_display_alter().
+*
+* This hook is called once per field per displayed entity. If the result of the
+* hook involves reading from the database, it is highly recommended to
+* statically cache the information.
+*
+* @param $display
+*   The display settings that will be used to display the field values, as
+*   found in the 'display' key of $instance definitions.
+* @param $context
+*   An associative array containing:
+*   - entity_type: The entity type; e.g., 'node' or 'user'.
+*   - field: The field being rendered.
+*   - instance: The instance being rendered.
+*   - entity: The entity being rendered.
+*   - view_mode: The view mode, e.g. 'full', 'teaser'...
+*
+* @see hook_field_display_alter()
+*/
+function hook_field_display_ENTITY_TYPE_alter(&$display, $context) {
+// Leave field labels out of the search index.
+if ($context['view_mode'] == 'search_index') {
+$display['label'] = 'hidden';
+}
+}
+/**
+* @} End of "addtogroup field_types
+*/
+/**
+* Alters the display settings of pseudo-fields before an entity is displayed.
+*
+* This hook is called once per displayed entity. If the result of the hook
+* involves reading from the database, it is highly recommended to statically
+* cache the information.
+*
+* @param $displays
+*   An array of display settings for the pseudo-fields in the entity, keyed
+*   by pseudo-field names.
+* @param $context
+*   An associative array containing:
+*   - entity_type: The entity type; e.g., 'node' or 'user'.
+*   - bundle: The bundle name.
+*   - view_mode: The view mode, e.g. 'full', 'teaser'...
+*
+* @ingroup field_types
+*/
+function hook_field_extra_fields_display_alter(&$displays, $context) {
+if ($context['entity_type'] == 'taxonomy_term' && $context['view_mode'] == 'full') {
+$displays['description']['visible'] = FALSE;
+}
+}
+/**
+* Alters the widget properties of a field instance on a given entity type
+* before it gets displayed.
+*
+* Modules can implement hook_field_widget_properties_ENTITY_TYPE_alter() to
+* alter the widget properties for fields on a specific entity type, rather than
+* implementing hook_field_widget_properties_alter().
+*
+* This hook is called once per field per displayed widget entity. If the result
+* of the hook involves reading from the database, it is highly recommended to
+* statically cache the information.
+*
+* @param $widget
+*   The instance's widget properties.
+* @param $context
+*   An associative array containing:
+*   - entity_type: The entity type; e.g., 'node' or 'user'.
+*   - entity: The entity object.
+*   - field: The field that the widget belongs to.
+*   - instance: The instance of the field.
+*
+* @see hook_field_widget_properties_alter()
+*
+* @ingroup field_widget
+*/
+function hook_field_widget_properties_ENTITY_TYPE_alter(&$widget, $context) {
+// Change a widget's type according to the time of day.
+$field = $context['field'];
+if ($field['field_name'] == 'field_foo') {
+$time = date('H');
+$widget['type'] = $time < 12 ? 'widget_am' : 'widget_pm';
+}
+}
+/**
+* @addtogroup field_crud
+* @{
+*/
+/**
+* Act on a field being created.
+*
+* This hook is invoked from field_create_field() after the field is created, to
+* allow modules to act on field creation.
+*
+* @param $field
+*   The field just created.
+*/
+function hook_field_create_field($field) {
+// @todo Needs function body.
+}
+/**
+* Act on a field instance being created.
+*
+* This hook is invoked from field_create_instance() after the instance record
+* is saved, so it cannot be used to modify the instance itself.
+*
+* @param $instance
+*   The instance just created.
+*/
+function hook_field_create_instance($instance) {
+// @todo Needs function body.
+}
+/**
+* Forbid a field update from occurring.
+*
+* Any module may forbid any update for any reason. For example, the
+* field's storage module might forbid an update if it would change
+* the storage schema while data for the field exists. A field type
+* module might forbid an update if it would change existing data's
+* semantics, or if there are external dependencies on field settings
+* that cannot be updated.
+*
+* To forbid the update from occurring, throw a FieldUpdateForbiddenException.
+*
+* @param $field
+*   The field as it will be post-update.
+* @param $prior_field
+*   The field as it is pre-update.
+* @param $has_data
+*   Whether any data already exists for this field.
+*/
+function hook_field_update_forbid($field, $prior_field, $has_data) {
+// A 'list' field stores integer keys mapped to display values. If
+// the new field will have fewer values, and any data exists for the
+// abandoned keys, the field will have no way to display them. So,
+// forbid such an update.
+if ($has_data && count($field['settings']['allowed_values']) < count($prior_field['settings']['allowed_values'])) {
+// Identify the keys that will be lost.
+$lost_keys = array_diff(array_keys($field['settings']['allowed_values']), array_keys($prior_field['settings']['allowed_values']));
+// If any data exist for those keys, forbid the update.
+$query = new EntityFieldQuery();
+$found = $query
+->fieldCondition($prior_field['field_name'], 'value', $lost_keys)
+->range(0, 1)
+->execute();
+if ($found) {
+throw new FieldUpdateForbiddenException("Cannot update a list field not to include keys with existing data");
+}
+}
+}
+/**
+* Act on a field being updated.
+*
+* This hook is invoked just after field is updated in field_update_field().
+*
+* @param $field
+*   The field as it is post-update.
+* @param $prior_field
+*   The field as it was pre-update.
+* @param $has_data
+*   Whether any data already exists for this field.
+*/
+function hook_field_update_field($field, $prior_field, $has_data) {
+// Reset the static value that keeps track of allowed values for list fields.
+drupal_static_reset('list_allowed_values');
+}
+/**
+* Act on a field being deleted.
+*
+* This hook is invoked just after a field is deleted by field_delete_field().
+*
+* @param $field
+*   The field just deleted.
+*/
+function hook_field_delete_field($field) {
+// @todo Needs function body.
+}
+/**
+* Act on a field instance being updated.
+*
+* This hook is invoked from field_update_instance() after the instance record
+* is saved, so it cannot be used by a module to modify the instance itself.
+*
+* @param $instance
+*   The instance as it is post-update.
+* @param $prior_instance
+*   The instance as it was pre-update.
+*/
+function hook_field_update_instance($instance, $prior_instance) {
+// @todo Needs function body.
+}
+/**
+* Act on a field instance being deleted.
+*
+* This hook is invoked from field_delete_instance() after the instance is
+* deleted.
+*
+* @param $instance
+*   The instance just deleted.
+*/
+function hook_field_delete_instance($instance) {
+// @todo Needs function body.
+}
+/**
+* Act on field records being read from the database.
+*
+* This hook is invoked from field_read_fields() on each field being read.
+*
+* @param $field
+*   The field record just read from the database.
+*/
+function hook_field_read_field($field) {
+// @todo Needs function body.
+}
+/**
+* Act on a field record being read from the database.
+*
+* This hook is invoked from field_read_instances() on each instance being read.
+*
+* @param $instance
+*   The instance record just read from the database.
+*/
+function hook_field_read_instance($instance) {
+// @todo Needs function body.
+}
+/**
+* Acts when a field record is being purged.
+*
+* In field_purge_field(), after the field configuration has been
+* removed from the database, the field storage module has had a chance to
+* run its hook_field_storage_purge_field(), and the field info cache
+* has been cleared, this hook is invoked on all modules to allow them to
+* respond to the field being purged.
+*
+* @param $field
+*   The field being purged.
+*/
+function hook_field_purge_field($field) {
+db_delete('my_module_field_info')
+->condition('id', $field['id'])
+->execute();
+}
+/**
+* Acts when a field instance is being purged.
+*
+* In field_purge_instance(), after the field instance has been
+* removed from the database, the field storage module has had a chance to
+* run its hook_field_storage_purge_instance(), and the field info cache
+* has been cleared, this hook is invoked on all modules to allow them to
+* respond to the field instance being purged.
+*
+* @param $instance
+*   The instance being purged.
+*/
+function hook_field_purge_instance($instance) {
+db_delete('my_module_field_instance_info')
+->condition('id', $instance['id'])
+->execute();
+}
+/**
+* Remove field storage information when a field record is purged.
+*
+* Called from field_purge_field() to allow the field storage module
+* to remove field information when a field is being purged.
+*
+* @param $field
+*   The field being purged.
+*
+* @ingroup field_storage
+*/
+function hook_field_storage_purge_field($field) {
+$table_name = _field_sql_storage_tablename($field);
+$revision_name = _field_sql_storage_revision_tablename($field);
+db_drop_table($table_name);
+db_drop_table($revision_name);
+}
+/**
+* Remove field storage information when a field instance is purged.
+*
+* Called from field_purge_instance() to allow the field storage module
+* to remove field instance information when a field instance is being
+* purged.
+*
+* @param $instance
+*   The instance being purged.
+*
+* @ingroup field_storage
+*/
+function hook_field_storage_purge_field_instance($instance) {
+db_delete('my_module_field_instance_info')
+->condition('id', $instance['id'])
+->execute();
+}
+/**
+* Remove field storage information when field data is purged.
+*
+* Called from field_purge_data() to allow the field storage
+* module to delete field data information.
+*
+* @param $entity_type
+*   The type of $entity; for example, 'node' or 'user'.
+* @param $entity
+*   The pseudo-entity whose field data to delete.
+* @param $field
+*   The (possibly deleted) field whose data is being purged.
+* @param $instance
+*   The deleted field instance whose data is being purged.
+*
+* @ingroup field_storage
+*/
+function hook_field_storage_purge($entity_type, $entity, $field, $instance) {
+list($id, $vid, $bundle) = entity_extract_ids($entity_type, $entity);
+$table_name = _field_sql_storage_tablename($field);
+$revision_name = _field_sql_storage_revision_tablename($field);
+db_delete($table_name)
+->condition('entity_type', $entity_type)
+->condition('entity_id', $id)
+->execute();
+db_delete($revision_name)
+->condition('entity_type', $entity_type)
+->condition('entity_id', $id)
+->execute();
+}
+/**
+* @} End of "addtogroup field_crud".
+*/
+/**
+* Determine whether the user has access to a given field.
+*
+* This hook is invoked from field_access() to let modules block access to
+* operations on fields. If no module returns FALSE, the operation is allowed.
+*
+* @param $op
+*   The operation to be performed. Possible values: 'edit', 'view'.
+* @param $field
+*   The field on which the operation is to be performed.
+* @param $entity_type
+*   The type of $entity; for example, 'node' or 'user'.
+* @param $entity
+*   (optional) The entity for the operation.
+* @param $account
+*   (optional) The account to check; if not given use currently logged in user.
+*
+* @return
+*   TRUE if the operation is allowed, and FALSE if the operation is denied.
+*
+* @ingroup field_types
+*/
+function hook_field_access($op, $field, $entity_type, $entity, $account) {
+if ($field['field_name'] == 'field_of_interest' && $op == 'edit') {
+return user_access('edit field of interest', $account);
+}
+return TRUE;
+}
+/**
+* @} End of "addtogroup hooks".
+*/