Field Types API

Defines field, widget, display formatter, and storage 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().

Field types are plugins annotated with class \Drupal\Core\Field\Annotation\FieldType, and implement plugin interface \Drupal\Core\Field\FieldItemInterface. Field Type plugins are managed by the \Drupal\Core\Field\FieldTypePluginManager class. Field type classes usually extend base class \Drupal\Core\Field\FieldItemBase. Field-type plugins need to be in the namespace \Drupal\{your_module}\Plugin\Field\FieldType. See the Plugin API topic for more information on how to define plugins.

The Field Types API also defines two kinds of pluggable handlers: widgets and formatters. Widgets specify how the field appears in edit forms, while formatters specify how the field appears in displayed entities.

See Field API for information about the other parts of the Field API.

See also

Field API

Field Widget API

Field Formatter API

Plugin API

Parent topics

Hooks

Define functions that alter the behavior of Drupal core.

File

core/modules/field/field.api.php, line 13

Field API documentation.

Functions

Name	Location	Description
hook_field_formatter_settings_summary_alter	core/modules/field_ui/field_ui.api.php	Alters the field formatter settings summary.
hook_field_formatter_third_party_settings_form	core/modules/field_ui/field_ui.api.php	Allow modules to add settings to field formatters provided by other modules.
hook_field_info_alter	core/modules/field/field.api.php	Perform alterations on Field API field types.
hook_field_storage_config_update_forbid	core/modules/field/field.api.php	Forbid a field storage update from occurring.
hook_field_widget_settings_summary_alter	core/modules/field_ui/field_ui.api.php	Alters the field widget settings summary.
hook_field_widget_third_party_settings_form	core/modules/field_ui/field_ui.api.php	Allow modules to add settings to field widgets provided by other modules.

Classes

Name	Location	Description
FieldItemBase	core/lib/Drupal/Core/Field/FieldItemBase.php	An entity field item.
FieldType	core/lib/Drupal/Core/Field/Annotation/FieldType.php	Defines a FieldType annotation object.
FieldTypePluginManager	core/lib/Drupal/Core/Field/FieldTypePluginManager.php	Plugin manager for 'field type' plugins.

Interfaces

Name	Location	Description
FieldItemInterface	core/lib/Drupal/Core/Field/FieldItemInterface.php	Interface for entity field items.
FieldTypePluginManagerInterface	core/lib/Drupal/Core/Field/FieldTypePluginManagerInterface.php	Defines an interface for the field type plugin manager.