field.module 50.4 KB
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<?php
/**
 * @file
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 * Attach custom data fields to Drupal entities.
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 */

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use Drupal\Core\Entity\EntityFieldQuery;
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use Drupal\Core\Template\Attribute;
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/*
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 * 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.
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 */
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require_once DRUPAL_ROOT . '/core/modules/field/field.crud.inc';
require_once DRUPAL_ROOT . '/core/modules/field/field.default.inc';
require_once DRUPAL_ROOT . '/core/modules/field/field.info.inc';
require_once DRUPAL_ROOT . '/core/modules/field/field.multilingual.inc';
require_once DRUPAL_ROOT . '/core/modules/field/field.attach.inc';
require_once DRUPAL_ROOT . '/core/modules/field/field.form.inc';
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/**
 * @defgroup field Field API
 * @{
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 * Attaches 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.
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 *
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 * 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'.
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 *
 * Field definitions are represented as an array of key/value pairs.
 *
 * array $field:
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 * - id: (integer, read-only) The primary identifier of the field. It is
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 *   assigned automatically by field_create_field().
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 * - field_name: (string) The name of the field. Each field name is unique
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 *   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.
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 * - type: (string) The type of the field, such as 'text' or 'image'. Field
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 *   types are defined by modules that implement hook_field_info().
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 * - 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
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 *   values are any positive integer or FIELD_CARDINALITY_UNLIMITED.
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 * - translatable: (integer) Whether the field is translatable.
 * - locked: (integer) Whether or not the field is available for editing. If
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 *   TRUE, users can't change field settings or create new instances of the
 *   field in the UI. Defaults to FALSE.
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 * - module: (string, read-only) The name of the module that implements the
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 *   field type.
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 * - active: (integer, read-only) TRUE if the module that implements the field
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 *   type is currently enabled, FALSE otherwise.
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 * - deleted: (integer, read-only) TRUE if this field has been deleted, FALSE
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 *   otherwise. Deleted fields are ignored by the Field Attach API. This
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 *   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 onthe 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
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 *   definition format as Schema API index specifications. Only columns that
 *   appear in the 'columns' setting are allowed. Note that field types can
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 *   specify default indexes, which can be modified or added to when creating a
 *   field.
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 * - foreign keys: (optional) An associative array of relations, using the same
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 *   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.
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 * - settings: (array) A sub-array of key/value pairs of field-type-specific
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 *   settings. Each field type module defines and documents its own field
 *   settings.
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 * - 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
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 *     are defined by modules that implement hook_field_storage_info().
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 *   - module: (string, read-only) The name of the module that implements the
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 *     storage backend.
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 *   - active: (integer, read-only) TRUE if the module that implements the
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 *     storage backend is currently enabled, FALSE otherwise.
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 *   - settings: (array) A sub-array of key/value pairs of settings. Each
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 *     storage backend defines and documents its own settings.
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 *
 * Field instance definitions are represented as an array of key/value pairs.
 *
 * array $instance:
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 * - 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
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 *   field_create_instance().
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 * - field_name: (string) The name of the field attached to the bundle by this
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 *   instance.
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 * - entity_type: (string) The name of the entity type the instance is attached
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 *   to.
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 * - 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
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 *   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().
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 * - default_value_function: (string) The name of the function, if any, that
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 *   will provide a default value.
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 * - default_value: (array) If default_value_function is not set, then fixed
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 *   values can be provided.
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 * - 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
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 *   instance settings. Each field type module defines and documents its own
 *   instance settings.
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 * - 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
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 *     types are defined by modules that implement hook_field_widget_info().
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 *   - 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
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 *     in entity edit forms.
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 *   - module: (string, read-only) The name of the module that implements the
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 *     widget type.
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 * - display: (array) A sub-array of key/value pairs identifying the way field
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 *   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
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 *   '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.
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 *     - ...
 *   - other_mode:
 *     - ...
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 *
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 * The (default) render arrays produced for field instances are documented at
 * field_attach_view().
 *
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 * Bundles are represented by two strings, an entity type and a bundle name.
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 *
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 * - @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
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 *   multilingual support for the Field API.
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 */

/**
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 * Value for field API indicating a field accepts an unlimited number of values.
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 */
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const FIELD_CARDINALITY_UNLIMITED = -1;
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/**
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 * Value for field API indicating a widget doesn't accept default values.
 *
 * @see hook_field_widget_info()
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 */
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const FIELD_BEHAVIOR_NONE = 0x0001;
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/**
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 * 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.
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 */
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const FIELD_BEHAVIOR_DEFAULT = 0x0002;
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/**
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 * Value for field API indicating a widget can receive several field values.
 *
 * @see hook_field_widget_info()
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 */
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const FIELD_BEHAVIOR_CUSTOM = 0x0004;
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/**
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 * Load the most recent version of an entity's field data.
 *
 * @see field_attach_load().
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 */
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const FIELD_LOAD_CURRENT = 'FIELD_LOAD_CURRENT';
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/**
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 * Load the version of an entity's field data specified in the entity.
 *
 * @see field_attach_load().
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 */
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const FIELD_LOAD_REVISION = 'FIELD_LOAD_REVISION';
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/**
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 * Implements hook_help().
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 */
function field_help($path, $arg) {
  switch ($path) {
    case 'admin/help#field':
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      $output = '';
      $output .= '<h3>' . t('About') . '</h3>';
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      $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>';
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      $output .= '<h3>' . t('Uses') . '</h3>';
      $output .= '<dl>';
      $output .= '<dt>' . t('Enabling field types') . '</dt>';
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      $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')));
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      // 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>';
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      $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/8', '@sql-store' => url('admin/help/field_sql_storage'))) . '</dd>';
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      $output .= '</dl>';
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      return $output;
  }
}

/**
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 * Implements hook_theme().
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 */
function field_theme() {
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  return array(
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    'field' => array(
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      'render element' => 'element',
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    ),
    'field_multiple_value_form' => array(
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      'render element' => 'element',
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    ),
  );
}

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/**
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 * Implements hook_cron().
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 */
function field_cron() {
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  // Refresh the 'active' status of fields.
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  field_sync_field_status();
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  // Do a pass of purging on deleted Field API data, if any exists.
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  $limit = variable_get('field_purge_batch_size', 10);
  field_purge_batch($limit);
}

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/**
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 * Implements hook_system_info_alter().
 *
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 * Goes through a list of all modules that provide a field type and makes them
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 * required if there are any active fields of that type.
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 */
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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')) {
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          $explanation = t('Field type(s) in use - see <a href="@fields-page">Field list</a>', array('@fields-page' => url('admin/reports/fields')));
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        }
        else {
          $explanation = t('Fields type(s) in use');
        }
      }
      else {
        $explanation = t('Fields pending deletion');
      }
      $info['explanation'] = $explanation;
    }
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  }
}

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/**
 * Applies language fallback rules to the fields attached to the given entity.
 *
 * Core language fallback rules simply check if fields have a field translation
 * for the requested language code. If so, the requested language is returned,
 * otherwise all the fallback candidates are inspected to see if there is a
 * field translation available in another language.
 * By default this is called by field_field_language_alter(), but this
 * behavior can be disabled by setting the 'field_language_fallback'
 * variable to FALSE.
 *
 * @param $field_langcodes
 *   A reference to an array of language codes keyed by field name.
 * @param $entity
 *   The entity to be displayed.
 * @param $langcode
 *   The language code $entity has to be displayed in.
 */
function field_language_fallback(&$field_langcodes, $entity, $langcode) {
  // Lazily init fallback candidates to avoid unnecessary calls.
  $fallback_candidates = NULL;

  foreach ($field_langcodes as $field_name => $field_langcode) {
    // If the requested language is defined for the current field use it,
    // otherwise search for a fallback value among the fallback candidates.
    if (isset($entity->{$field_name}[$langcode])) {
      $field_langcodes[$field_name] = $langcode;
    }
    elseif (!empty($entity->{$field_name})) {
      if (!isset($fallback_candidates)) {
        require_once DRUPAL_ROOT . '/core/includes/language.inc';
        $fallback_candidates = language_fallback_get_candidates();
      }
      foreach ($fallback_candidates as $fallback_langcode) {
        if (isset($entity->{$field_name}[$fallback_langcode])) {
          $field_langcodes[$field_name] = $fallback_langcode;
          break;
        }
      }
    }
  }
}

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/**
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 * Implements hook_cache_flush().
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 */
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function field_cache_flush() {
  // Request a flush of our cache table.
  return array('field');
}

/**
 * Implements hook_rebuild().
 */
function field_rebuild() {
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  // Refresh the 'active' status of fields.
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  field_sync_field_status();
}

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/**
 * 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();
}

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/**
 * 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.
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  $modules = module_list();
  foreach ($modules as $module_name) {
    field_associate_fields($module_name);
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  }
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  db_update('field_config')
    ->fields(array('active' => 0))
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    ->condition('module', $modules, 'NOT IN')
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    ->execute();
  db_update('field_config')
    ->fields(array('storage_active' => 0))
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    ->condition('storage_module', $modules, 'NOT IN')
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    ->execute();
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}

/**
 * Allows a module to update the database for fields and columns it controls.
 *
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 * @param $module
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 *   The name of the module to update on.
 */
function field_associate_fields($module) {
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  // Associate field types.
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  $field_types = (array) module_invoke($module, 'field_info');
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  if ($field_types) {
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    db_update('field_config')
      ->fields(array('module' => $module, 'active' => 1))
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      ->condition('type', array_keys($field_types))
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      ->execute();
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  }
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  // Associate storage backends.
  $storage_types = (array) module_invoke($module, 'field_storage_info');
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  if ($storage_types) {
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    db_update('field_config')
      ->fields(array('storage_module' => $module, 'storage_active' => 1))
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      ->condition('storage_type', array_keys($storage_types))
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      ->execute();
  }
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}

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/**
 * Returns the PluginManager object for a given field plugin type.
 *
 * @param string $plugin_type
 *   The plugin type. One of:
 *   - field_type
 *   - widget
 *   - formatter
 *   - storage
 *
 * @return Drupal\Component\Plugin\PluginManagerInterface
 *   The PluginManager object.
 */
function field_get_plugin_manager($plugin_type) {
  $plugin_types = &drupal_static(__FUNCTION__, array());

  $classes = array(
    'widget' => 'Drupal\field\Plugin\Type\Widget\WidgetPluginManager',
  );

  if (isset($classes[$plugin_type])) {
    if (!isset($plugin_types[$plugin_type])) {
      $plugin_types[$plugin_type] = new $classes[$plugin_type]();
    }

    return $plugin_types[$plugin_type];
  }
}

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/**
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 * Helper function to get the default value for a field on an entity.
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 *
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 * @param $entity_type
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 *   The type of $entity; e.g., 'node' or 'user'.
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 * @param $entity
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 *   The entity for the operation.
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 * @param $field
 *   The field structure.
 * @param $instance
 *   The instance structure.
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 * @param $langcode
 *   The field language to fill-in with the default value.
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 */
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function field_get_default_value($entity_type, $entity, $field, $instance, $langcode = NULL) {
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  $items = array();
  if (!empty($instance['default_value_function'])) {
    $function = $instance['default_value_function'];
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    $items = $function($entity_type, $entity, $field, $instance, $langcode);
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  }
  elseif (!empty($instance['default_value'])) {
    $items = $instance['default_value'];
  }
  return $items;
}

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/**
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 * Filters out empty field values.
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 *
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 * @param $field
 *   The field definition.
 * @param $items
 *   The field values to filter.
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 *
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 * @return
 *   The array of items without empty field values. The function also renumbers
 *   the array keys to ensure sequential deltas.
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 */
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function _field_filter_items($field, $items) {
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  $function = $field['module'] . '_field_is_empty';
  foreach ((array) $items as $delta => $item) {
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    // Explicitly break if the function is undefined.
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    if ($function($item, $field)) {
      unset($items[$delta]);
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    }
  }
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  return array_values($items);
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}

/**
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 * Sorts items in a field according to user drag-and-drop reordering.
 *
 * @param $field
 *   The field definition.
 * @param $items
 *   The field values to sort.
 *
 * @return
 *   The sorted array of field items.
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 */
function _field_sort_items($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']);
      }
    }
  }
  return $items;
}

/**
589 590 591
 * Callback for usort() within _field_sort_items().
 *
 * Copied form element_sort(), which acts on #weight keys.
592 593
 */
function _field_sort_items_helper($a, $b) {
594 595 596
  $a_weight = (is_array($a) ? $a['_weight'] : 0);
  $b_weight = (is_array($b) ? $b['_weight'] : 0);
  return $a_weight - $b_weight;
597 598 599
}

/**
600 601 602
 * Callback for usort() within theme_field_multiple_value_form().
 *
 * Sorts using ['_weight']['#value']
603 604
 */
function _field_sort_items_value_helper($a, $b) {
605 606 607
  $a_weight = (is_array($a) && isset($a['_weight']['#value']) ? $a['_weight']['#value'] : 0);
  $b_weight = (is_array($b) && isset($b['_weight']['#value']) ? $b['_weight']['#value'] : 0);
  return $a_weight - $b_weight;
608 609
}

610
/**
611 612
 * Gets or sets administratively defined bundle settings.
 *
613
 * @param string $entity_type
614
 *   The type of $entity; e.g., 'node' or 'user'.
615
 * @param string $bundle
616
 *   The bundle name.
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 * @param array|null $settings
 *   (optional) The settings to store, an associative array with the following
 *   elements:
 *   - view_modes: An associative array keyed by view mode, with the following
 *     key/value pairs:
 *     - custom_settings: Boolean specifying whether the view mode uses a
 *       dedicated set of display options (TRUE), or the 'default' options
 *       (FALSE). Defaults to FALSE.
 *   - extra_fields: An associative array containing the form and display
 *     settings for extra fields (also known as pseudo-fields):
 *     - form: An associative array whose keys are the names of extra fields,
 *       and whose values are associative arrays with the following elements:
 *       - weight: The weight of the extra field, determining its position on an
 *         entity form.
 *     - display: An associative array whose keys are the names of extra fields,
 *       and whose values are associative arrays keyed by the name of view
 *       modes. This array must include an item for the 'default' view mode.
 *       Each view mode sub-array contains the following elements:
 *       - weight: The weight of the extra field, determining its position when
 *         an entity is viewed.
 *       - visible: TRUE if the extra field is visible, FALSE otherwise.
638
 *
639
 * @return array|null
640 641 642 643
 *   If no $settings are passed, the current settings are returned.
 */
function field_bundle_settings($entity_type, $bundle, $settings = NULL) {
  if (isset($settings)) {
644
    variable_set('field_bundle_settings_' . $entity_type . '__' . $bundle, $settings);
645
    field_info_cache_clear();
646 647
  }
  else {
648
    $settings = variable_get('field_bundle_settings_' . $entity_type . '__' . $bundle, array());
649 650 651 652
    $settings += array(
      'view_modes' => array(),
      'extra_fields' => array(),
    );
653 654 655 656
    $settings['extra_fields'] += array(
      'form' => array(),
      'display' => array(),
    );
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    return $settings;
  }
}

/**
 * Returns view mode settings in a given bundle.
 *
 * @param $entity_type
 *   The type of entity; e.g. 'node' or 'user'.
 * @param $bundle
 *   The bundle name to return view mode settings for.
 *
 * @return
 *   An array keyed by view mode, with the following key/value pairs:
 *   - custom_settings: Boolean specifying whether the view mode uses a
 *     dedicated set of display options (TRUE), or the 'default' options
 *     (FALSE). Defaults to FALSE.
 */
function field_view_mode_settings($entity_type, $bundle) {
  $cache = &drupal_static(__FUNCTION__, array());

  if (!isset($cache[$entity_type][$bundle])) {
    $bundle_settings = field_bundle_settings($entity_type, $bundle);
    $settings = $bundle_settings['view_modes'];
    // Include view modes for which nothing has been stored yet, but whose
    // definition in hook_entity_info() specify they should use custom settings
    // by default.
    $entity_info = entity_get_info($entity_type);
    foreach ($entity_info['view modes'] as $view_mode => $view_mode_info) {
      if (!isset($settings[$view_mode]['custom_settings']) && $view_mode_info['custom settings']) {
        $settings[$view_mode]['custom_settings'] = TRUE;
      }
    }
    $cache[$entity_type][$bundle] = $settings;
  }

  return $cache[$entity_type][$bundle];
}

/**
 * Returns the display settings to use for an instance in a given view mode.
 *
 * @param $instance
 *   The field instance being displayed.
 * @param $view_mode
 *   The view mode.
704 705
 * @param $entity
 *   The entity being displayed.
706 707 708 709
 *
 * @return
 *   The display settings to be used when displaying the field values.
 */
710
function field_get_display($instance, $view_mode, $entity) {
711 712 713 714 715 716 717 718 719 720 721
  // Check whether the view mode uses custom display settings or the 'default'
  // mode.
  $view_mode_settings = field_view_mode_settings($instance['entity_type'], $instance['bundle']);
  $actual_mode = (!empty($view_mode_settings[$view_mode]['custom_settings']) ? $view_mode : 'default');
  $display = $instance['display'][$actual_mode];

  // Let modules alter the display settings.
  $context = array(
    'entity_type' => $instance['entity_type'],
    'field' => field_info_field($instance['field_name']),
    'instance' => $instance,
722
    'entity' => $entity,
723 724 725 726 727
    'view_mode' => $view_mode,
  );
  drupal_alter(array('field_display', 'field_display_' . $instance['entity_type']), $display, $context);

  return $display;
728 729 730
}

/**
731
 * Returns the display settings to use for pseudo-fields in a given view mode.
732
 *
733
 * @param $entity_type
734
 *   The type of $entity; e.g., 'node' or 'user'.
735 736
 * @param $bundle
 *   The bundle name.
737 738 739
 * @param $view_mode
 *   The view mode.
 *
740
 * @return
741 742 743 744 745 746 747
 *   The display settings to be used when viewing the bundle's pseudo-fields.
 */
function field_extra_fields_get_display($entity_type, $bundle, $view_mode) {
  // Check whether the view mode uses custom display settings or the 'default'
  // mode.
  $view_mode_settings = field_view_mode_settings($entity_type, $bundle);
  $actual_mode = (!empty($view_mode_settings[$view_mode]['custom_settings'])) ? $view_mode : 'default';
748
  $extra_fields = field_info_extra_fields($entity_type, $bundle, 'display');
749 750 751 752

  $displays = array();
  foreach ($extra_fields as $name => $value) {
    $displays[$name] = $extra_fields[$name]['display'][$actual_mode];
753
  }
754 755 756 757 758 759 760 761 762 763

  // Let modules alter the display settings.
  $context = array(
    'entity_type' => $entity_type,
    'bundle' => $bundle,
    'view_mode' => $view_mode,
  );
  drupal_alter('field_extra_fields_display', $displays, $context);

  return $displays;
764 765 766
}

/**
767
 * Pre-render callback: Adjusts weights and visibility of non-field elements.
768
 */
769 770 771 772 773
function _field_extra_fields_pre_render($elements) {
  $entity_type = $elements['#entity_type'];
  $bundle = $elements['#bundle'];

  if (isset($elements['#type']) && $elements['#type'] == 'form') {
774
    $extra_fields = field_info_extra_fields($entity_type, $bundle, 'form');
775 776 777
    foreach ($extra_fields as $name => $settings) {
      if (isset($elements[$name])) {
        $elements[$name]['#weight'] = $settings['weight'];
778
      }
779 780 781 782 783 784 785 786 787 788
    }
  }
  elseif (isset($elements['#view_mode'])) {
    $view_mode = $elements['#view_mode'];
    $extra_fields = field_extra_fields_get_display($entity_type, $bundle, $view_mode);
    foreach ($extra_fields as $name => $settings) {
      if (isset($elements[$name])) {
        $elements[$name]['#weight'] = $settings['weight'];
        // Visibility: make sure we do not accidentally show a hidden element.
        $elements[$name]['#access'] = isset($elements[$name]['#access']) ? ($elements[$name]['#access'] && $settings['visible']) : $settings['visible'];
789 790 791
      }
    }
  }
792

793 794 795
  return $elements;
}

796
/**
797
 * Clears the field info and field data caches.
798
 */
799
function field_cache_clear() {
800
  cache('field')->flush();
801
  field_info_cache_clear();
802 803 804
}

/**
805 806
 * Filters an HTML string to prevent cross-site-scripting (XSS) vulnerabilities.
 *
807 808
 * Like filter_xss_admin(), but with a shorter list of allowed tags.
 *
809 810 811 812 813 814 815 816 817 818
 * Used for items entered by administrators, like field descriptions, allowed
 * values, where some (mainly inline) mark-up may be desired (so
 * drupal_htmlspecialchars() is not acceptable).
 *
 * @param $string
 *   The string with raw HTML in it.
 *
 * @return
 *   An XSS safe version of $string, or an empty string if $string is not valid
 *   UTF-8.
819 820 821 822 823 824
 */
function field_filter_xss($string) {
  return filter_xss($string, _field_filter_xss_allowed_tags());
}

/**
825
 * Returns a list of tags allowed by field_filter_xss().
826 827 828 829 830 831
 */
function _field_filter_xss_allowed_tags() {
  return array('a', 'b', 'big',  'code', 'del', 'em', 'i', 'ins',  'pre', 'q', 'small', 'span', 'strong', 'sub', 'sup', 'tt', 'ol', 'ul', 'li', 'p', 'br', 'img');
}

/**
832
 * Returns a human-readable list of allowed tags for display in help texts.
833 834 835 836 837 838
 */
function _field_filter_xss_display_allowed_tags() {
  return '<' . implode('> <', _field_filter_xss_allowed_tags()) . '>';
}

/**
839
 * Returns a renderable array for a single field value.
840
 *
841
 * @param $entity_type
842
 *   The type of $entity; e.g., 'node' or 'user'.
843
 * @param $entity
844
 *   The entity containing the field to display. Must at least contain the ID
845 846 847
 *   key and the field data to display.
 * @param $field_name
 *   The name of the field to display.
848
 * @param $item
849 850 851
 *   The field value to display, as found in
 *   $entity->field_name[$langcode][$delta].
 * @param $display
852 853
 *   Can be either the name of a view mode, or an array of display settings. See
 *   field_view_field() for more information.
854
 * @param $langcode
855 856 857
 *   (Optional) The language of the value in $item. If not provided, the current
 *   language will be assumed.
 *
858
 * @return
859
 *   A renderable array for the field value.
860
 */
861 862
function field_view_value($entity_type, $entity, $field_name, $item, $display = array(), $langcode = NULL) {
  $output = array();
863

864 865
  if ($field = field_info_field($field_name)) {
    // Determine the langcode that will be used by language fallback.
866
    $langcode = field_language($entity_type, $entity, $field_name, $langcode);
867

868 869 870 871 872
    // Push the item as the single value for the field, and defer to
    // field_view_field() to build the render array for the whole field.
    $clone = clone $entity;
    $clone->{$field_name}[$langcode] = array($item);
    $elements = field_view_field($entity_type, $clone, $field_name, $display, $langcode);
873

874 875 876 877
    // Extract the part of the render array we need.
    $output = isset($elements[0]) ? $elements[0] : array();
    if (isset($elements['#access'])) {
      $output['#access'] = $elements['#access'];
878 879
    }
  }
880 881

  return $output;
882 883 884
}

/**
885
 * Returns a renderable array for the value of a single field in an entity.
886
 *
887
 * The resulting output is a fully themed field with label and multiple values.
888
 *
889 890 891 892
 * This function can be used by third-party modules that need to output an
 * isolated field.
 * - Do not use inside node (or other entities) templates, use
 *   render($content[FIELD_NAME]) instead.
893
 * - Do not use to display all fields in an entity, use
894
 *   field_attach_prepare_view() and field_attach_view() instead.
895 896
 * - The field_view_value() function can be used to output a single formatted
 *   field value, without label or wrapping field markup.
897
 *
898 899 900
 * The function takes care of invoking the prepare_view steps. It also respects
 * field access permissions.
 *
901
 * @param $entity_type
902
 *   The type of $entity; e.g., 'node' or 'user'.
903
 * @param $entity
904
 *   The entity containing the field to display. Must at least contain the ID
905 906 907 908 909
 *   key and the field data to display.
 * @param $field_name
 *   The name of the field to display.
 * @param $display
 *   Can be either:
910 911
 *   - The name of a view mode. The field will be displayed according to the
 *     display settings specified for this view mode in the $instance
912 913 914
 *     definition for the field in the entity's bundle. If no display settings
 *     are found for the view mode, the settings for the 'default' view mode
 *     will be used.
915
 *   - An array of display settings, as found in the 'display' entry of
916
 *     $instance definitions. The following key/value pairs are allowed:
917 918 919 920
 *     - label: (string) Position of the label. The default 'field' theme
 *       implementation supports the values 'inline', 'above' and 'hidden'.
 *       Defaults to 'above'.
 *     - type: (string) The formatter to use. Defaults to the
921 922 923
 *       'default_formatter' for the field type, specified in hook_field_info().
 *       The default formatter will also be used if the requested formatter is
 *       not available.
924
 *     - settings: (array) Settings specific to the formatter. Defaults to the
925
 *       formatter's default settings, specified in hook_field_formatter_info().
926 927 928
 *     - weight: (float) The weight to assign to the renderable element.
 *       Defaults to 0.
 * @param $langcode
929 930
 *   (Optional) The language code the field values are to be shown in. The
 *   site's current language fallback logic will be applied when no values are
931
 *   available for the given language code. If no language code is provided the
932
 *   current language will be used.
933
 *
934
 * @return
935
 *   A renderable array for the field value.
936 937
 *
 * @see field_view_value()
938
 */
939
function field_view_field($entity_type, $entity, $field_name, $display = array(), $langcode = NULL) {
940
  $output = array();
941

942 943 944 945 946
  if ($field = field_info_field($field_name)) {
    if (is_array($display)) {
      // When using custom display settings, fill in default values.
      $display = _field_info_prepare_instance_display($field, $display);
    }
947

948 949
    // Hook invocations are done through the _field_invoke() functions in
    // 'single field' mode, to reuse the language fallback logic.
950 951 952 953
    // Determine the actual language code to display for the field, given the
    // language codes available in the field data.
    $display_langcode = field_language($entity_type, $entity, $field_name, $langcode);
    $options = array('field_name' => $field_name, 'langcode' => $display_langcode);
954 955
    $null = NULL;

956 957
    // Invoke prepare_view steps if needed.
    if (empty($entity->_field_view_prepared)) {
958
      $id = $entity->id();
959 960 961 962 963 964 965

      // First let the field types do their preparation.
      _field_invoke_multiple('prepare_view', $entity_type, array($id => $entity), $display, $null, $options);
      // Then let the formatters do their own specific massaging.
      _field_invoke_multiple_default('prepare_view', $entity_type, array($id => $entity), $display, $null, $options);
    }

966
    // Build the renderable array.
967
    $result = _field_invoke_default('view', $entity_type, $entity, $display, $null, $options);
968

969
    // Invoke hook_field_attach_view_alter() to let other modules alter the
970 971
    // renderable array, as in a full field_attach_view() execution.
    $context = array(
972 973
      'entity_type' => $entity_type,
      'entity' => $entity,
974
      'view_mode' => '_custom',
975
      'display' => $display,
976 977
    );
    drupal_alter('field_attach_view', $result, $context);
978

979 980 981
    if (isset($result[$field_name])) {
      $output = $result[$field_name];
    }
982
  }
983

984 985 986
  return $output;
}

987 988 989 990
/**
 * Returns the field items in the language they currently would be displayed.
 *
 * @param $entity_type
991
 *   The type of $entity; e.g., 'node' or 'user'.
992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007
 * @param $entity
 *   The entity containing the data to be displayed.
 * @param $field_name
 *   The field to be displayed.
 * @param $langcode
 *   (optional) The language code $entity->{$field_name} has to be displayed in.
 *   Defaults to the current language.
 *
 * @return
 *   An array of field items keyed by delta if available, FALSE otherwise.
 */
function field_get_items($entity_type, $entity, $field_name, $langcode = NULL) {
  $langcode = field_language($entity_type, $entity, $field_name, $langcode);
  return isset($entity->{$field_name}[$langcode]) ? $entity->{$field_name}[$langcode] : FALSE;
}

1008
/**
1009
 * Determines whether a field has any data.
1010 1011 1012
 *
 * @param $field
 *   A field structure.
1013
 *
1014
 * @return
1015
 *   TRUE if the field has data for any entity; FALSE otherwise.
1016 1017
 */
function field_has_data($field) {
1018 1019 1020 1021 1022
  $query = new EntityFieldQuery();
  return (bool) $query
    ->fieldCondition($field)
    ->range(0, 1)
    ->count()
1023 1024 1025 1026
    // Neutralize the 'entity_field_access' query tag added by
    // field_sql_storage_field_storage_query(). The result cannot depend on the
    // access grants of the current user.
    ->addTag('DANGEROUS_ACCESS_CHECK_OPT_OUT')
1027
    ->execute();
1028 1029
}

1030
/**
1031
 * Determines whether the user has access to a given field.
1032
 *
1033
 * @param string $op
1034
 *   The operation to be performed. Possible values:
1035 1036
 *   - edit
 *   - view
1037 1038 1039 1040
 * @param array $field
 *   The full field structure array for the field on which the operation is to
 *   be performed. See field_info_field().
 * @param string $entity_type
1041
 *   The type of $entity; e.g., 'node' or 'user'.
1042
 * @param $entity
1043
 *   (optional) The entity for the operation.
1044 1045
 * @param $account
 *   (optional) The account to check, if not given use currently logged in user.
1046
 *
1047
 * @return
1048
 *   TRUE if the operation is allowed; FALSE if the operation is denied.
1049
 */
1050
function field_access($op, $field, $entity_type, $entity = NULL, $account = NULL) {
1051 1052
  global $user;

1053
  if (!isset($account)) {
1054 1055 1056
    $account = $user;
  }

1057 1058
  foreach (module_implements('field_access') as $module) {
    $function = $module . '_field_acc