<?php

/**

 * @file

 * Attach custom data fields to Drupal entities.

 */

/**

 * Base class for all exceptions thrown by Field API functions.

 *

 * This class has no functionality of its own other than allowing all

 * Field API exceptions to be caught by a single catch block.

 */

class FieldException extends Exception {}

/*

 * Load all public Field API functions. Drupal currently has no

 * mechanism for auto-loading core APIs, so we have to load them on

 * every page request.

 */

require_once DRUPAL_ROOT . '/modules/field/field.crud.inc';

require_once DRUPAL_ROOT . '/modules/field/field.default.inc';

require_once DRUPAL_ROOT . '/modules/field/field.info.inc';

require_once DRUPAL_ROOT . '/modules/field/field.multilingual.inc';

require_once DRUPAL_ROOT . '/modules/field/field.attach.inc';

require_once DRUPAL_ROOT . '/modules/field/field.form.inc';

/**

 * @defgroup field Field API

 * @{

 * Attach custom data fields to Drupal entities.

 *

 * The Field API allows custom data fields to be attached to Drupal

 * entities and takes care of storing, loading, editing, and rendering

 * field data. Any entity type (node, user, etc.) can use the Field

 * API to make itself "fieldable" and thus allow fields to be attached

 * to it. Other modules can provide a user interface for managing custom

 * fields via a web browser as well as a wide and flexible variety of

 * data type, form element, and display format capabilities.

 *

 * The Field API defines two primary data structures, Field and

 * Instance, and the concept of a Bundle. A Field defines a

 * particular type of data that can be attached to entities. A Field

 * Instance is a Field attached to a single Bundle. A Bundle is a set

 * of fields that are treated as a group by the Field Attach API and

 * is related to a single fieldable entity type.

 *

 * For example, suppose a site administrator wants Article nodes to

 * have a subtitle and photo. Using the Field API or Field UI module,

 * the administrator creates a field named 'subtitle' of type 'text'

 * and a field named 'photo' of type 'image'. The administrator

 * (again, via a UI) creates two Field Instances, one attaching the

 * field 'subtitle' to the 'node' bundle 'article' and one attaching

 * the field 'photo' to the 'node' bundle 'article'. When the node

 * system uses the Field Attach API to load all fields for an Article

 * node, it passes the node's entity type (which is 'node') and

 * content type (which is 'article') as the node's bundle.

 * field_attach_load() then loads the 'subtitle' and 'photo' fields

 * because they are both attached to the 'node' bundle 'article'.

 *

 * Field definitions are represented as an array of key/value pairs.

 *

 * array $field:

 * - id (integer, read-only): The primary identifier of the field. It is

 *   assigned automatically by field_create_field().

 * - field_name (string): The name of the field. Each field name is unique

 *   within Field API. When a field is attached to an entity, the field's data

 *   is stored in $entity->$field_name. Maximum length is 32 characters.

 * - type (string): The type of the field, such as 'text' or 'image'. Field

 *   types are defined by modules that implement hook_field_info().

 * - entity_types (array): The array of entity types that can hold instances

 *   of this field. If empty or not specified, the field can have instances

 *   in any entity type.

 * - cardinality (integer): The number of values the field can hold. Legal

 *   values are any positive integer or FIELD_CARDINALITY_UNLIMITED.

 * - translatable (integer): Whether the field is translatable.

 * - locked (integer): Whether or not the field is available for editing. If

 *   TRUE, users can't change field settings or create new instances of the

 *   field in the UI. Defaults to FALSE.

 * - module (string, read-only): The name of the module that implements the

 *   field type.

 * - active (integer, read-only): TRUE if the module that implements the field

 *   type is currently enabled, FALSE otherwise.

 * - deleted (integer, read-only): TRUE if this field has been deleted, FALSE

 *   otherwise. Deleted fields are ignored by the Field Attach API. This

 *   property exists because fields can be marked for deletion but only

 *   actually destroyed by a separate garbage-collection process.

 * - columns (array, read-only): An array of the Field API columns used to

 *   store each value of this field. The column list may depend on field

 *   settings; it is not constant per field type. Field API column

 *   specifications are exactly like Schema API column specifications but,

 *   depending on the field storage module in use, the name of the column may

 *   not represent an actual column in an SQL database.

 * - indexes (array): An array of indexes on data columns, using the same

 *   definition format as Schema API index specifications. Only columns that

 *   appear in the 'columns' setting are allowed. Note that field types can

 *   specify default indexes, which can be modified or added to when

 *   creating a field.

 * - foreign keys: (optional) An associative array of relations, using the same

 *   structure as the 'foreign keys' definition of hook_schema(). Note,

 *   however, that the field data is not necessarily stored in SQL. Also, the

 *   possible usage is limited, as you cannot specify another field as

 *   related, only existing SQL tables, such as filter formats.

 * - settings (array): A sub-array of key/value pairs of field-type-specific

 *   settings. Each field type module defines and documents its own field

 *   settings.

 * - storage (array): A sub-array of key/value pairs identifying the storage

 *   backend to use for the for the field:

 *   - type (string): The storage backend used by the field. Storage backends

 *     are defined by modules that implement hook_field_storage_info().

 *   - module (string, read-only): The name of the module that implements the

 *     storage backend.

 *   - active (integer, read-only): TRUE if the module that implements the

 *     storage backend is currently enabled, FALSE otherwise.

 *   - settings (array): A sub-array of key/value pairs of settings. Each

 *     storage backend defines and documents its own settings.

 *

 * Field instance definitions are represented as an array of key/value pairs.

 *

 * array $instance:

 * - id (integer, read-only): The primary identifier of this field instance.

 *   It is assigned automatically by field_create_instance().

 * - field_id (integer, read-only): The foreign key of the field attached to

 *   the bundle by this instance. It is populated automatically by

 *   field_create_instance().

 * - field_name (string): The name of the field attached to the bundle by this

 *   instance.

 * - entity_type (string): The name of the entity type the instance is attached

 *   to.

 * - bundle (string): The name of the bundle that the field is attached to.

 * - label (string): A human-readable label for the field when used with this

 *   bundle. For example, the label will be the title of Form API elements

 *   for this instance.

 * - description (string): A human-readable description for the field when

 *   used with this bundle. For example, the description will be the help

 *   text of Form API elements for this instance.

 * - required (integer): TRUE if a value for this field is required when used

 *   with this bundle, FALSE otherwise. Currently, required-ness is only

 *   enforced during Form API operations, not by field_attach_load(),

 *   field_attach_insert(), or field_attach_update().

 * - default_value_function (string): The name of the function, if any, that

 *   will provide a default value.

 * - default_value (array): If default_value_function is not set, then fixed

 *   values can be provided.

 * - deleted (integer, read-only): TRUE if this instance has been deleted,

 *   FALSE otherwise. Deleted instances are ignored by the Field Attach API.

 *   This property exists because instances can be marked for deletion but

 *   only actually destroyed by a separate garbage-collection process.

 * - settings (array): A sub-array of key/value pairs of field-type-specific

 *   instance settings. Each field type module defines and documents its own

 *   instance settings.

 * - widget (array): A sub-array of key/value pairs identifying the Form API

 *   input widget for the field when used by this bundle:

 *   - type (string): The type of the widget, such as text_textfield. Widget

 *     types are defined by modules that implement hook_field_widget_info().

 *   - settings (array): A sub-array of key/value pairs of

 *     widget-type-specific settings. Each field widget type module defines

 *     and documents its own widget settings.

 *   - weight (float): The weight of the widget relative to the other elements

 *     in entity edit forms.

 *   - module (string, read-only): The name of the module that implements the

 *     widget type.

 * - display (array): A sub-array of key/value pairs identifying the way field

 *   values should be displayed in each of the entity type's view modes, plus

 *   the 'default' mode. For each view mode, Field UI lets site administrators

 *   define whether they want to use a dedicated set of display options or the

 *   'default' options to reduce the number of displays to maintain as they

 *   add new fields. For nodes, on a fresh install, only the 'teaser' view

 *   mode is configured to use custom display options, all other view modes

 *   defined use the 'default' options by default. When programmatically

 *   adding field instances on nodes, it is therefore recommended to at least

 *   specify display options for 'default' and 'teaser':

 *   - default (array): A sub-array of key/value pairs describing the display

 *     options to be used when the field is being displayed in view modes

 *     that are not configured to use dedicated display options:

 *     - label (string): Position of the label. 'inline', 'above' and

 *       'hidden' are the values recognized by the default 'field' theme

 *       implementation.

 *     - type (string): The type of the display formatter, or 'hidden' for

 *       no display.

 *     - settings (array): A sub-array of key/value pairs of display

 *       options specific to the formatter.

 *     - weight (float): The weight of the field relative to the other entity

 *       components displayed in this view mode.

 *     - module (string, read-only): The name of the module which implements

 *       the display formatter.

 *   - some_mode: A sub-array of key/value pairs describing the display

 *     options to be used when the field is being displayed in the 'some_mode'

 *     view mode. Those options will only be actually applied at run time if

 *     the view mode is not configured to use default settings for this bundle:

 *     - ...

 *   - other_mode:

 *     - ...

 *

 * The (default) render arrays produced for field instances are documented at

 * field_attach_view().

 *

 * Bundles are represented by two strings, an entity type and a bundle name.

 *

 * - @link field_types Field Types API @endlink. Defines field types,

 *   widget types, and display formatters. Field modules use this API

 *   to provide field types like Text and Node Reference along with the

 *   associated form elements and display formatters.

 *

 * - @link field_crud Field CRUD API @endlink. Create, updates, and

 *   deletes fields, bundles (a.k.a. "content types"), and instances.

 *   Modules use this API, often in hook_install(), to create

 *   custom data structures.

 *

 * - @link field_attach Field Attach API @endlink. Connects entity

 *   types to the Field API. Field Attach API functions load, store,

 *   generate Form API structures, display, and perform a variety of

 *   other functions for field data connected to individual entities.

 *   Fieldable entity types like node and user use this API to make

 *   themselves fieldable.

 *

 * - @link field_info Field Info API @endlink. Exposes information

 *   about all fields, instances, widgets, and related information

 *   defined by or with the Field API.

 *

 * - @link field_storage Field Storage API @endlink. Provides a

 *   pluggable back-end storage system for actual field data. The

 *   default implementation, field_sql_storage.module, stores field data

 *   in the local SQL database.

 *

 * - @link field_purge Field API bulk data deletion @endlink. Cleans

 *   up after bulk deletion operations such as field_delete_field()

 *   and field_delete_instance().

 *

 * - @link field_language Field language API @endlink. Provides native

 *   multilingual support for the Field API.

 */

/**

 * Value for field API indicating a field accepts an unlimited number of values.

 */

define('FIELD_CARDINALITY_UNLIMITED', -1);

/**

 * Value for field API indicating a widget doesn't accept default values.

 *

 * @see hook_field_widget_info()

 */

define('FIELD_BEHAVIOR_NONE', 0x0001);

/**

 * Value for field API concerning widget default and multiple value settings.

 *

 * @see hook_field_widget_info()

 *

 * When used in a widget default context, indicates the widget accepts default

 * values. When used in a multiple value context for a widget that allows the

 * input of one single field value, indicates that the widget will be repeated

 * for each value input.

 */

define('FIELD_BEHAVIOR_DEFAULT', 0x0002);

/**

 * Value for field API indicating a widget can receive several field values.

 *

 * @see hook_field_widget_info()

 */

define('FIELD_BEHAVIOR_CUSTOM', 0x0004);

/**

 * Age argument for loading the most recent version of an entity's

 * field data with field_attach_load().

 */

define('FIELD_LOAD_CURRENT', 'FIELD_LOAD_CURRENT');

/**

 * Age argument for loading the version of an entity's field data

 * specified in the entity with field_attach_load().

 */

define('FIELD_LOAD_REVISION', 'FIELD_LOAD_REVISION');

/**

 * Exception class thrown by hook_field_update_forbid().

 */

class FieldUpdateForbiddenException extends FieldException {}

/**

 * Implements hook_help().

 */

function field_help($path, $arg) {

  switch ($path) {

    case 'admin/help#field':

      $output = '';

      $output .= '<h3>' . t('About') . '</h3>';

      $output .= '<p>' . t('The Field module allows custom data fields to be defined for <em>entity</em> types (entities include content items, comments, user accounts, and taxonomy terms). The Field module takes care of storing, loading, editing, and rendering field data. Most users will not interact with the Field module directly, but will instead use the <a href="@field-ui-help">Field UI module</a> user interface. Module developers can use the Field API to make new entity types "fieldable" and thus allow fields to be attached to them. For more information, see the online handbook entry for <a href="@field">Field module</a>.', array('@field-ui-help' => url('admin/help/field_ui'), '@field' => 'http://drupal.org/documentation/modules/field')) . '</p>';

      $output .= '<h3>' . t('Uses') . '</h3>';

      $output .= '<dl>';

      $output .= '<dt>' . t('Enabling field types') . '</dt>';

      $output .= '<dd>' . t('The Field module provides the infrastructure for fields and field attachment; the field types and input widgets themselves are provided by additional modules. Some of the modules are required; the optional modules can be enabled from the <a href="@modules">Modules administration page</a>. Drupal core includes the following field type modules: Number (required), Text (required), List (required), Taxonomy (optional), Image (optional), and File (optional); the required Options module provides input widgets for other field modules. Additional fields and widgets may be provided by contributed modules, which you can find in the <a href="@contrib">contributed module section of Drupal.org</a>. Currently enabled field and input widget modules:', array('@modules' => url('admin/modules'), '@contrib' => 'http://drupal.org/project/modules', '@options' => url('admin/help/options')));

      // Make a list of all widget and field modules currently enabled, in

      // order by displayed module name (module names are not translated).

      $items = array();

      $info = system_get_info('module');

      $modules = array_merge(module_implements('field_info'), module_implements('field_widget_info'));

      $modules = array_unique($modules);

      sort($modules);

      foreach ($modules as $module) {

        $display = $info[$module]['name'];

        if (module_hook($module, 'help')) {

          $items['items'][] = l($display, 'admin/help/' . $module);

        }

        else {

          $items['items'][] = $display;

        }

      }

      $output .= theme('item_list', $items) . '</dd>';

      $output .= '<dt>' . t('Managing field data storage') . '</dt>';

      $output .= '<dd>' . t('Developers of field modules can either use the default <a href="@sql-store">Field SQL storage module</a> to store data for their fields, or a contributed or custom module developed using the <a href="@storage-api">field storage API</a>.', array('@storage-api' => 'http://api.drupal.org/api/group/field_storage/7', '@sql-store' => url('admin/help/field_sql_storage'))) . '</dd>';

      $output .= '</dl>';

      return $output;

  }

}

/**

 * Implements hook_permission().

 */

function field_permission() {

  return array(

    'administer fields' => array(

      'title' => t('Administer fields'),

      'description' => t('Additional permissions are required based on what the fields are attached to (for example, <a href="@url">administer content types</a> to manage fields attached to content).', array(

        '@url' => '#module-node',

      )),

      'restrict access' => TRUE,

    ),

  );

}

/**

 * Implements hook_theme().

 */

function field_theme() {

  return array(

    'field' => array(

      'render element' => 'element',

    ),

    'field_multiple_value_form' => array(

      'render element' => 'element',

    ),

  );

}

/**

 * Implements hook_cron().

 */

function field_cron() {

  // Refresh the 'active' status of fields.

  field_sync_field_status();

  // Do a pass of purging on deleted Field API data, if any exists.

  $limit = variable_get('field_purge_batch_size', 10);

  field_purge_batch($limit);

}

/**

 * Implements hook_system_info_alter().

 *

 * Goes through a list of all modules that provide a field type, and makes them

 * required if there are any active fields of that type.

 */

function field_system_info_alter(&$info, $file, $type) {

  if ($type == 'module' && module_hook($file->name, 'field_info')) {

    $fields = field_read_fields(array('module' => $file->name), array('include_deleted' => TRUE));

    if ($fields) {

      $info['required'] = TRUE;

      // Provide an explanation message (only mention pending deletions if there

      // remains no actual, non-deleted fields)

      $non_deleted = FALSE;

      foreach ($fields as $field) {

        if (empty($field['deleted'])) {

          $non_deleted = TRUE;

          break;

        }

      }

      if ($non_deleted) {

        if (module_exists('field_ui')) {

          $explanation = t('Field type(s) in use - see <a href="@fields-page">Field list</a>', array('@fields-page' => url('admin/reports/fields')));

        }

        else {

          $explanation = t('Fields type(s) in use');

        }

      }

      else {

        $explanation = t('Fields pending deletion');

      }

      $info['explanation'] = $explanation;

    }

  }

}

/**

 * Implements hook_flush_caches().

 */

function field_flush_caches() {

  // Refresh the 'active' status of fields.

  field_sync_field_status();

  // Request a flush of our cache table.

  return array('cache_field');

}

/**

 * Implements hook_modules_enabled().

 */

function field_modules_enabled($modules) {

  // Refresh the 'active' status of fields.

  field_sync_field_status();

}

/**

 * Implements hook_modules_disabled().

 */

function field_modules_disabled($modules) {

  // Refresh the 'active' status of fields.

  field_sync_field_status();

}

/**

 * Refreshes the 'active' and 'storage_active' columns for fields.

 */

function field_sync_field_status() {

  // Refresh the 'active' and 'storage_active' columns according to the current

  // set of enabled modules.

  $modules = module_list();

  foreach ($modules as $module_name) {

    field_associate_fields($module_name);

  }

  db_update('field_config')

    ->fields(array('active' => 0))

    ->condition('module', $modules, 'NOT IN')

    ->execute();

  db_update('field_config')

    ->fields(array('storage_active' => 0))

    ->condition('storage_module', $modules, 'NOT IN')

    ->execute();

}

/**

 * Allows a module to update the database for fields and columns it controls.

 *

 * @param $module

 *   The name of the module to update on.

 */

function field_associate_fields($module) {

  // Associate field types.

  $field_types = (array) module_invoke($module, 'field_info');

  if ($field_types) {

    db_update('field_config')

      ->fields(array('module' => $module, 'active' => 1))

      ->condition('type', array_keys($field_types))

      ->execute();

  }

  // Associate storage backends.

  $storage_types = (array) module_invoke($module, 'field_storage_info');

  if ($storage_types) {

    db_update('field_config')

      ->fields(array('storage_module' => $module, 'storage_active' => 1))

      ->condition('storage_type', array_keys($storage_types))

      ->execute();

  }

}

/**

 * Helper function to get the default value for a field on an entity.

 *

 * @param $entity_type

 *   The type of $entity; e.g., 'node' or 'user'.

 * @param $entity

 *   The entity for the operation.

 * @param $field

 *   The field structure.

 * @param $instance

 *   The instance structure.

 * @param $langcode

 *   The field language to fill-in with the default value.

 */

function field_get_default_value($entity_type, $entity, $field, $instance, $langcode = NULL) {

  $items = array();

  if (!empty($instance['default_value_function'])) {

    $function = $instance['default_value_function'];

    if (function_exists($function)) {

      $items = $function($entity_type, $entity, $field, $instance, $langcode);

    }

  }

  elseif (!empty($instance['default_value'])) {

    $items = $instance['default_value'];

  }

  return $items;

}

/**

 * Helper function to filter out empty field values.

 *

 * @param $field

 *   The field definition.

 * @param $items

 *   The field values to filter.

 *

 * @return

 *   The array of items without empty field values. The function also renumbers

 *   the array keys to ensure sequential deltas.

 */

function _field_filter_items($field, $items) {

  $function = $field['module'] . '_field_is_empty';

  foreach ((array) $items as $delta => $item) {

    // Explicitly break if the function is undefined.

    if ($function($item, $field)) {

      unset($items[$delta]);

    }

  }

  return array_values($items);

}

/**

 * Helper function to sort items in a field according to

 * user drag-n-drop reordering.

 */

function _field_sort_items($field, $items) {

  if (($field['cardinality'] > 1 || $field['cardinality'] == FIELD_CARDINALITY_UNLIMITED) && isset($items[0]['_weight'])) {

    usort($items, '_field_sort_items_helper');

    foreach ($items as $delta => $item) {

      if (is_array($items[$delta])) {

        unset($items[$delta]['_weight']);