Documentation & API reference
Field API
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.
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 Types API: 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.
- Field CRUD API: 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.
- Field Attach API: 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.
- Field Info API: Exposes information about all fields, instances, widgets, and related information defined by or with the Field API.
- Field Storage API: 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.
- Field API bulk data deletion: Cleans up after bulk deletion operations such as field_delete_field() and field_delete_instance().
- Field language API: Provides native multilingual support for the Field API.
File
- drupal/
core/ modules/ field/ field.module, line 23 - Attach custom data fields to Drupal entities.
Functions
Name |
Location | Description |
|---|---|---|
| field_access |
drupal/ |
Determines whether the user has access to a given field. |
| field_bundle_settings |
drupal/ |
Gets or sets administratively defined bundle settings. |
| field_cache_clear |
drupal/ |
Clears the field info and field data caches. |
| field_cron |
drupal/ |
Implements hook_cron(). |
| field_data_type_info |
drupal/ |
Implements hook_data_type_info() to register data types for all field types. |
| field_entity_create |
drupal/ |
Implements hook_entity_create(). |
| field_entity_field_info |
drupal/ |
Implements hook_entity_field_info() to define all configured fields. |
| field_extract_bundle |
drupal/ |
Extracts the bundle name from a bundle object. |
| field_field_widget_info_alter |
drupal/ |
Implements hook_field_widget_info_alter(). |
| field_filter_xss |
drupal/ |
Filters an HTML string to prevent cross-site-scripting (XSS) vulnerabilities. |
| field_get_default_value |
drupal/ |
Helper function to get the default value for a field on an entity. |
| field_get_items |
drupal/ |
Returns the field items in the language they currently would be displayed. |
| field_has_data |
drupal/ |
Determines whether a field has any data. |
| field_help |
drupal/ |
Implements hook_help(). |
| field_language_fallback |
drupal/ |
Applies language fallback rules to the fields attached to the given entity. |
| field_modules_disabled |
drupal/ |
Implements hook_modules_disabled(). |
| field_modules_enabled |
drupal/ |
Implements hook_modules_enabled(). |
| field_page_build |
drupal/ |
Implements hook_page_build(). |
| field_populate_default_values |
drupal/ |
Inserts a default value for each entity field not having one. |
| field_rebuild |
drupal/ |
Implements hook_rebuild(). |
| field_sync_field_status |
drupal/ |
Refreshes the 'active' and 'storage[active]' values for fields. |
| field_system_info_alter |
drupal/ |
Implements hook_system_info_alter(). |
| field_theme |
drupal/ |
Implements hook_theme(). |
| field_ui_instance_load |
drupal/ |
Menu loader callback: Loads a field instance based on field and bundle name. |
| field_view_field |
drupal/ |
Returns a renderable array for the value of a single field in an entity. |
| field_view_mode_settings |
drupal/ |
Returns view mode settings in a given bundle. |
| field_view_value |
drupal/ |
Returns a renderable array for a single field value. |
| template_preprocess_field |
drupal/ |
Prepares variables for field templates. |
| template_process_field |
drupal/ |
Theme process function for theme_field() and field.html.twig. |
| _field_filter_items |
drupal/ |
Filters out empty field values. |
| _field_filter_xss_allowed_tags |
drupal/ |
Returns a list of tags allowed by field_filter_xss(). |
| _field_filter_xss_display_allowed_tags |
drupal/ |
Returns a human-readable list of allowed tags for display in help texts. |
| _field_sort_items |
drupal/ |
Sorts items in a field according to user drag-and-drop reordering. |
| _field_sort_items_helper |
drupal/ |
Callback for usort() within _field_sort_items(). |
| _field_sort_items_value_helper |
drupal/ |
Callback for usort() within theme_field_multiple_value_form(). |
Constants
|
Name |
Location | Description |
|---|---|---|
| FIELD_BEHAVIOR_CUSTOM |
drupal/ |
Value for field API indicating a widget can receive several field values. |
| FIELD_BEHAVIOR_DEFAULT |
drupal/ |
Value for field API concerning widget default and multiple value settings. |
| FIELD_BEHAVIOR_NONE |
drupal/ |
Value for field API indicating a widget doesn't accept default values. |
| FIELD_CARDINALITY_UNLIMITED |
drupal/ |
Value for field API indicating a field accepts an unlimited number of values. |
| FIELD_LOAD_CURRENT |
drupal/ |
Load the most recent version of an entity's field data. |
| FIELD_LOAD_REVISION |
drupal/ |
Load the version of an entity's field data specified in the entity. |