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interface FieldDefinitionInterface in Drupal 9

Same name and namespace in other branches
  1. 8 core/lib/Drupal/Core/Field/FieldDefinitionInterface.php \Drupal\Core\Field\FieldDefinitionInterface

Defines an interface for entity field definitions.

An entity field is a data object that holds the values of a particular field for a particular entity (see \Drupal\Core\Field\FieldItemListInterface). For example, $node_1->body and $node_2->body contain different data and therefore are different field objects.

In contrast, an entity field *definition* is an object that returns information *about* a field (e.g., its type and settings) rather than its values. As such, if all the information about $node_1->body and $node_2->body is the same, then the same field definition object can be used to describe both.

It is up to the class implementing this interface to manage where the information comes from. For example, field.module provides an implementation based on two levels of configuration. It allows the site administrator to add custom fields to any entity type and bundle via the "field_storage_config" and "field_config" configuration entities. The former for storing configuration that is independent of which entity type and bundle the field is added to, and the latter for storing configuration that is specific to the entity type and bundle. The class that implements "field_config" configuration entities also implements this interface, returning information from either itself, or from the corresponding "field_storage_config" configuration, as appropriate.

However, entity base fields, such as $node->title, are not managed by field.module and its "field_storage_config"/"field_config" configuration entities. Therefore, their definitions are provided by different objects based on the class \Drupal\Core\Field\BaseFieldDefinition, which implements this interface as well.

Field definitions may fully define a concrete data object (e.g., $node_1->body), or may provide a best-guess definition for a data object that might come into existence later. For example, $node_1->body and $node_2->body may have different definitions (e.g., if the node types are different). When adding the "body" field to a View that can return nodes of different types, the View can get a field definition that represents the "body" field abstractly, and present Views configuration options to the administrator based on that abstract definition, even though that abstract definition can differ from the concrete definition of any particular node's body field.

Hierarchy

Expanded class hierarchy of FieldDefinitionInterface

All classes that implement FieldDefinitionInterface

129 files declare their use of FieldDefinitionInterface
AggregatorTitleFormatter.php in core/modules/aggregator/src/Plugin/Field/FieldFormatter/AggregatorTitleFormatter.php
AuthorFormatter.php in core/modules/user/src/Plugin/Field/FieldFormatter/AuthorFormatter.php
AuthorNameFormatter.php in core/modules/comment/src/Plugin/Field/FieldFormatter/AuthorNameFormatter.php
BaseFieldFileFormatterBase.php in core/modules/file/src/Plugin/Field/FieldFormatter/BaseFieldFileFormatterBase.php
BooleanItem.php in core/lib/Drupal/Core/Field/Plugin/Field/FieldType/BooleanItem.php

... See full list

File

core/lib/Drupal/Core/Field/FieldDefinitionInterface.php, line 51

Namespace

Drupal\Core\Field
View source 
interface FieldDefinitionInterface extends ListDataDefinitionInterface, CacheableDependencyInterface {

  /**
   * Returns the machine name of the field.
   *
   * This defines how the field data is accessed from the entity. For example,
   * if the field name is "foo", then $entity->foo returns its data.
   *
   * @return string
   *   The field name.
   */
  public function getName();

  /**
   * Returns the field type.
   *
   * @return string
   *   The field type, i.e. the id of a field type plugin. For example 'text'.
   *
   * @see \Drupal\Core\Field\FieldTypePluginManagerInterface
   */
  public function getType();

  /**
   * Returns the ID of the entity type the field is attached to.
   *
   * This method should not be confused with EntityInterface::getEntityTypeId()
   * (configurable fields are config entities, and thus implement both
   * interfaces):
   *   - FieldDefinitionInterface::getTargetEntityTypeId() answers "as a field,
   *     which entity type are you attached to?".
   *   - EntityInterface::getEntityTypeId() answers "as a (config) entity, what
   *     is your own entity type?".
   *
   * @return string
   *   The entity type ID.
   */
  public function getTargetEntityTypeId();

  /**
   * Gets the bundle the field is attached to.
   *
   * This method should not be confused with EntityInterface::bundle()
   * (configurable fields are config entities, and thus implement both
   * interfaces):
   *   - FieldDefinitionInterface::getTargetBundle() answers "as a field,
   *     which bundle are you attached to?".
   *   - EntityInterface::bundle() answers "as a (config) entity, what
   *     is your own bundle?" (not relevant in our case, the config entity types
   *     used to store the definitions of configurable fields do not have
   *     bundles).
   *
   * @return string|null
   *   The bundle the field is defined for, or NULL if it is a base field; i.e.,
   *   it is not bundle-specific.
   */
  public function getTargetBundle();

  /**
   * Returns whether the display for the field can be configured.
   *
   * @param string $display_context
   *   The display context. Either 'view' or 'form'.
   *
   * @return bool
   *   TRUE if the display for this field is configurable in the given context.
   *   If TRUE, the display options returned by getDisplayOptions() may be
   *   overridden via the respective entity display.
   *
   * @see \Drupal\Core\Entity\Display\EntityDisplayInterface
   */
  public function isDisplayConfigurable($display_context);

  /**
   * Returns the default display options for the field.
   *
   * If the field's display is configurable, the returned display options act
   * as default values and may be overridden via the respective entity display.
   * Otherwise, the display options will be applied to entity displays as is.
   *
   * @param string $display_context
   *   The display context. Either 'view' or 'form'.
   *
   * @return array|null
   *   The array of display options for the field, or NULL if the field is not
   *   displayed. The following key/value pairs may be present:
   *   - label: (string) Position of the field label. The default 'field' theme
   *     implementation supports the values 'inline', 'above' and 'hidden'.
   *     Defaults to 'above'. Only applies to 'view' context.
   *   - region: (string) The region the field is in, or 'hidden'. If not
   *     specified, the default region will be used.
   *   - type: (string) The plugin (widget or formatter depending on
   *     $display_context) to use. If not specified or if the requested plugin
   *     is unknown, the 'default_widget' / 'default_formatter' for the field
   *     type will be used. Previously 'hidden' was a valid value, it is now
   *     deprecated in favor of specifying 'region' => 'hidden'.
   *   - settings: (array) Settings for the plugin specified above. The default
   *     settings for the plugin will be used for settings left unspecified.
   *   - third_party_settings: (array) Settings provided by other extensions
   *     through hook_field_formatter_third_party_settings_form().
   *   - weight: (float) The weight of the element. Not needed if 'type' is
   *     'hidden'.
   *   The defaults of the various display options above get applied by the used
   *   entity display.
   *
   * @see \Drupal\Core\Entity\Display\EntityDisplayInterface
   */
  public function getDisplayOptions($display_context);

  /**
   * Returns whether the field can be empty.
   *
   * If a field is required, an entity needs to have at least a valid,
   * non-empty item in that field's FieldItemList in order to pass validation.
   *
   * An item is considered empty if its isEmpty() method returns TRUE.
   * Typically, that is if at least one of its required properties is empty.
   *
   * @return bool
   *   TRUE if the field is required.
   *
   * @see \Drupal\Core\TypedData\Plugin\DataType\ItemList::isEmpty()
   * @see \Drupal\Core\Field\FieldItemInterface::isEmpty()
   * @see \Drupal\Core\TypedData\DataDefinitionInterface:isRequired()
   * @see \Drupal\Core\TypedData\TypedDataManager::getDefaultConstraints()
   */
  public function isRequired();

  /**
   * Returns the default value literal for the field.
   *
   * This method retrieves the raw property assigned to the field definition.
   * When computing the runtime default value for a field in a given entity,
   * ::getDefaultValue() should be used instead.
   *
   * @return array
   *   The default value for the field, as a numerically indexed array of items,
   *   each item being a property/value array (array() for no default value).
   *
   * @see FieldDefinitionInterface::getDefaultValue()
   * @see FieldDefinitionInterface::getDefaultValueCallback()
   */
  public function getDefaultValueLiteral();

  /**
   * Returns the default value callback for the field.
   *
   * This method retrieves the raw property assigned to the field definition.
   * When computing the runtime default value for a field in a given entity,
   * ::getDefaultValue() should be used instead.
   *
   * @return string|null
   *   The default value callback for the field.
   *
   * @see FieldDefinitionInterface::getDefaultValue()
   * @see FieldDefinitionInterface::getDefaultValueLiteral()
   */
  public function getDefaultValueCallback();

  /**
   * Returns the default value for the field in a newly created entity.
   *
   * This method computes the runtime default value for a field in a given
   * entity. To access the raw properties assigned to the field definition,
   * ::getDefaultValueLiteral() or ::getDefaultValueCallback() should be used
   * instead.
   *
   * @param \Drupal\Core\Entity\FieldableEntityInterface $entity
   *   The entity for which the default value is generated.
   *
   * @return array
   *   The default value for the field, as a numerically indexed array of items,
   *   each item being a property/value array (array() for no default value).
   *
   * @see FieldDefinitionInterface::getDefaultValueLiteral()
   * @see FieldDefinitionInterface::getDefaultValueCallback()
   */
  public function getDefaultValue(FieldableEntityInterface $entity);

  /**
   * Returns whether the field is translatable.
   *
   * @return bool
   *   TRUE if the field is translatable.
   */
  public function isTranslatable();

  /**
   * Returns the field storage definition.
   *
   * @return \Drupal\Core\Field\FieldStorageDefinitionInterface
   *   The field storage definition.
   */
  public function getFieldStorageDefinition();

  /**
   * Gets an object that can be saved in configuration.
   *
   * Base fields are defined in code. In order to configure field definition
   * properties per bundle use this method to create an override that can be
   * saved in configuration.
   *
   * @see \Drupal\Core\Field\Entity\BaseFieldBundleOverride
   *
   * @param string $bundle
   *   The bundle to get the configurable field for.
   *
   * @return \Drupal\Core\Field\FieldConfigInterface
   */
  public function getConfig($bundle);

  /**
   * Returns a unique identifier for the field.
   *
   * @return string
   */
  public function getUniqueIdentifier();

}

Members

Namesort descending Modifiers Type Description Overrides
CacheableDependencyInterface::getCacheContexts public function The cache contexts associated with this object. 34
CacheableDependencyInterface::getCacheMaxAge public function The maximum age for which this object may be cached. 34
CacheableDependencyInterface::getCacheTags public function The cache tags associated with this object. 27
DataDefinitionInterface::addConstraint public function Adds a validation constraint. 2
DataDefinitionInterface::createFromDataType public static function Creates a new data definition object. 2
DataDefinitionInterface::getClass public function Returns the class used for creating the typed data object. 2
DataDefinitionInterface::getConstraint public function Returns a validation constraint. 2
DataDefinitionInterface::getConstraints public function Returns an array of validation constraints. 2
DataDefinitionInterface::getDataType public function Returns the data type of the data. 2
DataDefinitionInterface::getDescription public function Returns a human readable description. 2
DataDefinitionInterface::getLabel public function Returns a human readable label. 2
DataDefinitionInterface::getSetting public function Returns the value of a given setting. 2
DataDefinitionInterface::getSettings public function Returns the array of settings, as required by the used class. 2
DataDefinitionInterface::isComputed public function Determines whether the data value is computed. 3
DataDefinitionInterface::isInternal public function Determines whether the data value is internal. 2
DataDefinitionInterface::isList public function Returns whether the data is multi-valued, i.e. a list of data items. 2
DataDefinitionInterface::isReadOnly public function Determines whether the data is read-only. 3
FieldDefinitionInterface::getConfig public function Gets an object that can be saved in configuration. 3
FieldDefinitionInterface::getDefaultValue public function Returns the default value for the field in a newly created entity. 3
FieldDefinitionInterface::getDefaultValueCallback public function Returns the default value callback for the field. 3
FieldDefinitionInterface::getDefaultValueLiteral public function Returns the default value literal for the field. 3
FieldDefinitionInterface::getDisplayOptions public function Returns the default display options for the field. 4
FieldDefinitionInterface::getFieldStorageDefinition public function Returns the field storage definition. 4
FieldDefinitionInterface::getName public function Returns the machine name of the field. 3
FieldDefinitionInterface::getTargetBundle public function Gets the bundle the field is attached to. 3
FieldDefinitionInterface::getTargetEntityTypeId public function Returns the ID of the entity type the field is attached to. 3
FieldDefinitionInterface::getType public function Returns the field type. 3
FieldDefinitionInterface::getUniqueIdentifier public function Returns a unique identifier for the field. 4
FieldDefinitionInterface::isDisplayConfigurable public function Returns whether the display for the field can be configured. 4
FieldDefinitionInterface::isRequired public function Returns whether the field can be empty. Overrides DataDefinitionInterface::isRequired 1
FieldDefinitionInterface::isTranslatable public function Returns whether the field is translatable. 3
ListDataDefinitionInterface::createFromItemType public static function Creates a new list data definition for items of the given data type. 2
ListDataDefinitionInterface::getItemDefinition public function Gets the data definition of an item of the list. 2