Overview of extensions and alteration methods for Drupal. Types of extensions Drupal's core behavior can be extended and altered via these three basic types of extensions: Themes: Themes alter the appearance of Drupal sites. They can include template files, which alter the HTML markup and other raw output of the site; CSS files, which alter the styling applied to the HTML; and JavaScript, Flash, images, and other files. For more information, see the Theme system and render API topic and https:

Deletes the container if default language has changed. Hierarchy class \Drupal\language\EventSubscriber\ConfigSubscriber implements EventSubscriberInterface File core/modules/language/src/EventSubscriber/ConfigSubscriber.php, line 19 Namespace Drupal\language\EventSubscriber Members Name Modifiers Type Description ConfigSubscriber::$configFactory protected property The configuration factory. ConfigSubscriber::$languageDefault protected property The default langua

public EntityDefinitionUpdateManager::getEntityType($entity_type_id) Returns an entity type definition ready to be manipulated. When needing to apply updates to existing entity type definitions, this method should always be used to retrieve a definition ready to be manipulated. Parameters string $entity_type_id: The entity type identifier. Return value \Drupal\Core\Entity\EntityTypeInterface The entity type definition. Overrides EntityDefinitionUpdateManagerInterface::getEntityType File core/

public FieldStorageDefinitionInterface::isRevisionable() Returns whether the field is revisionable. Return value bool TRUE if the field is revisionable. File core/lib/Drupal/Core/Field/FieldStorageDefinitionInterface.php, line 105 Class FieldStorageDefinitionInterface Defines an interface for entity field storage definitions. Namespace Drupal\Core\Field Code public function isRevisionable();

public FieldStorageDefinitionInterface::getConstraint($constraint_name) Returns a validation constraint. See \Drupal\Core\TypedData\DataDefinitionInterface::getConstraints() for details. Parameters string $constraint_name: The name of the constraint, i.e. its plugin id. Return value array A validation constraint definition which can be used for instantiating a \Symfony\Component\Validator\Constraint object. See also \Symfony\Component\Validator\Constraint File core/lib/Drupal/Core/Field/Fiel

Defines a item list class for entity reference fields. Hierarchy class \Drupal\Core\TypedData\TypedData implements PluginInspectionInterface, TypedDataInterface uses StringTranslationTrait, TypedDataTraitclass \Drupal\Core\TypedData\Plugin\DataType\ItemList implements \IteratorAggregate, ListInterfaceclass \Drupal\Core\Field\FieldItemList implements FieldItemListInterfaceclass \Drupal\Core\Field\EntityReferenceFieldItemList implements EntityReferenceFieldItemListInterface File core/lib/Dr

The data to pass on to the client side. Type: string File core/lib/Drupal/Core/Ajax/BaseCommand.php, line 22 Class BaseCommand Base command that only exists to simplify AJAX commands. Namespace Drupal\Core\Ajax Code protected $data;

Contains data for serialization before sending the response. We do not want to abuse the $content property on the Response class to store our response data. $content implies that the provided data must either be a string or an object with a __toString() method, which is not a requirement for data used here. Hierarchy class \Symfony\Component\HttpFoundation\Responseclass \Drupal\rest\ResourceResponse implements CacheableResponseInterface, ResourceResponseInterface uses CacheableResponseTrait, Re

The language to be reverted. Type: string File core/modules/node/src/Form/NodeRevisionRevertTranslationForm.php, line 22 Class NodeRevisionRevertTranslationForm Provides a form for reverting a node revision for a single translation. Namespace Drupal\node\Form Code protected $langcode;

public static NestedArray::setValue(array &$array, array $parents, $value, $force = FALSE) Sets a value in a nested array with variable depth. This helper function should be used when the depth of the array element you are changing may vary (that is, the number of parent keys is variable). It is primarily used for form structures and renderable arrays. Example: // Assume you have a 'signature' element somewhere in a form. It might be: $form['signature_settings']['signature'] = array( '#ty