Issue #2226267 by fago, xjm, Berdir: Improve default value handling of fields to be consistent.

core/lib/Drupal/Core/Field/FieldDefinition.php

@@ -7,7 +7,7 @@
 
 namespace Drupal\Core\Field;
 
-use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Entity\ContentEntityInterface;
 use Drupal\Core\Field\TypedData\FieldItemDataDefinition;
 use Drupal\Core\TypedData\ListDataDefinition;
 use Drupal\field\FieldException;
@@ -378,8 +378,56 @@ public function isDisplayConfigurable($display_context) {
   /**
    * {@inheritdoc}
    */
-  public function getDefaultValue(EntityInterface $entity) {
-    return $this->getSetting('default_value');
+  public function getDefaultValue(ContentEntityInterface $entity) {
+    // Allow custom default values function.
+    if (isset($this->definition['default_value_callback'])) {
+      $value = call_user_func($this->definition['default_value_callback'], $entity, $this);
+    }
+    else {
+      $value = isset($this->definition['default_value']) ? $this->definition['default_value'] : NULL;
+    }
+    // Allow the field type to process default values.
+    $field_item_list_class = $this->getClass();
+    return $field_item_list_class::processDefaultValue($value, $entity, $this);
+  }
+
+  /**
+   * Sets a custom default value callback.
+   *
+   * If set, the callback overrides any set default value.
+   *
+   * @param string|array $callback
+   *   The callback to invoke for getting the default value. The callback will
+   *   be invoked with the following arguments:
+   *   - \Drupal\Core\Entity\ContentEntityInterface $entity
+   *     The entity being created.
+   *   - \Drupal\Core\Field\FieldDefinitionInterface $definition
+   *     The field definition.
+   *   It should return the default value as documented by
+   *   \Drupal\Core\Field\FieldDefinitionInterface::getDefaultValue().
+   *
+   * @return $this
+   */
+  public function setDefaultValueCallback($callback) {
+    $this->definition['default_value_callback'] = $callback;
+    return $this;
+  }
+
+  /**
+   * Sets a default value.
+   *
+   * Note that if a default value callback is set, it will take precedence over
+   * any value set here.
+   *
+   * @param mixed $value
+   *   The default value in the format as returned by
+   *   \Drupal\Core\Field\FieldDefinitionInterface::getDefaultValue().
+   *
+   * @return $this
+   */
+  public function setDefaultValue($value) {
+    $this->definition['default_value'] = $value;
+    return $this;
   }
 
   /**

core/lib/Drupal/Core/Field/FieldDefinitionInterface.php

@@ -7,7 +7,7 @@
 
 namespace Drupal\Core\Field;
 
-use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Entity\ContentEntityInterface;
 use Drupal\Core\TypedData\ListDataDefinitionInterface;
 
 /**
@@ -114,19 +114,19 @@ public function isRequired();
   /**
    * Returns the default value for the field in a newly created entity.
    *
-   * @param \Drupal\Core\Entity\EntityInterface $entity
-   *   The entity being created.
+   * @param \Drupal\Core\Entity\ContentEntityInterface $entity
+   *   The entity for which the default value is generated.
    *
    * @return mixed
    *   The default value for the field, as accepted by
-   *   Drupal\field\Plugin\Core\Entity\FieldConfig::setValue(). This can be
-   *   either:
+   *   \Drupal\field\Plugin\Core\Entity\FieldItemListInterface::setValue(). This
+   *   can be either:
    *   - a literal, in which case it will be assigned to the first property of
    *     the first item.
    *   - a numerically indexed array of items, each item being a property/value
    *     array.
    *   - NULL or array() for no default value.
    */
-  public function getDefaultValue(EntityInterface $entity);
+  public function getDefaultValue(ContentEntityInterface $entity);
 
 }

core/lib/Drupal/Core/Field/FieldItemList.php

@@ -7,6 +7,7 @@
 
 namespace Drupal\Core\Field;
 
+use Drupal\Core\Entity\ContentEntityInterface;
 use Drupal\Core\Session\AccountInterface;
 use Drupal\Core\TypedData\DataDefinitionInterface;
 use Drupal\Core\TypedData\TypedDataInterface;
@@ -202,7 +203,7 @@ public function defaultAccess($operation = 'view', AccountInterface $account = N
    * {@inheritdoc}
    */
   public function applyDefaultValue($notify = TRUE) {
-    $value = $this->getDefaultValue();
+    $value = $this->getFieldDefinition()->getDefaultValue($this->getEntity());
 
     // NULL or array() mean "no default value", but  0, '0' and the empty string
     // are valid default values.
@@ -216,16 +217,6 @@ public function applyDefaultValue($notify = TRUE) {
     return $this;
   }
 
-  /**
-   * Returns the default value for the field.
-   *
-   * @return array
-   *   The default value for the field.
-   */
-  protected function getDefaultValue() {
-    return $this->getFieldDefinition()->getDefaultValue($this->getEntity());
-  }
-
   /**
    * {@inheritdoc}
    */
@@ -347,6 +338,13 @@ public function defaultValuesFormSubmit(array $element, array &$form, array &$fo
     return $this->getValue();
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public static function processDefaultValue($default_value, ContentEntityInterface $entity, FieldDefinitionInterface $definition) {
+    return $default_value;
+  }
+
   /**
    * Returns the widget object used in default value form.
    *

core/lib/Drupal/Core/Field/FieldItemListInterface.php

@@ -7,6 +7,7 @@
 
 namespace Drupal\Core\Field;
 
+use Drupal\Core\Entity\ContentEntityInterface;
 use Drupal\Core\Session\AccountInterface;
 use Drupal\Core\Access\AccessibleInterface;
 use Drupal\Core\TypedData\ListInterface;
@@ -228,4 +229,30 @@ public function defaultValuesFormValidate(array $element, array &$form, array &$
    */
   public function defaultValuesFormSubmit(array $element, array &$form, array &$form_state);
 
+  /**
+   * Processes the default value before being applied.
+   *
+   * Defined or configured default values of a field might need some processing
+   * in order to be a valid value for the field type; e.g., a date field could
+   * process the defined value of 'NOW' to a valid date.
+   *
+   * @param mixed
+   *   The default value as defined for the field.
+   * @param \Drupal\Core\Entity\ContentEntityInterface $entity
+   *   The entity for which the default value is generated.
+   * @param \Drupal\Core\Field\FieldDefinitionInterface $definition
+   *   The definition of the field.
+   *
+   * @return mixed
+   *   The default value for the field, as accepted by
+   *   \Drupal\field\Plugin\Core\Entity\FieldItemListInterface::setValue(). This
+   *   can be either:
+   *   - a literal, in which case it will be assigned to the first property of
+   *     the first item.
+   *   - a numerically indexed array of items, each item being a property/value
+   *     array.
+   *   - NULL or array() for no default value.
+   */
+  public static function processDefaultValue($default_value, ContentEntityInterface $entity, FieldDefinitionInterface $definition);
+
 }

core/lib/Drupal/Core/Field/Plugin/Field/FieldType/StringItem.php

@@ -2,7 +2,7 @@
 
 /**
  * @file
- * Contains \Drupal\Core\Entity\Plugin\Field\FieldType\StringItem.
+ * Contains \Drupal\Core\Field\Plugin\Field\FieldType\StringItem.
  */
 
 namespace Drupal\Core\Field\Plugin\Field\FieldType;

core/modules/aggregator/src/Entity/Feed.php

@@ -176,12 +176,12 @@ public static function baseFieldDefinitions(EntityTypeInterface $entity_type) {
     $fields['checked'] = FieldDefinition::create('timestamp')
       ->setLabel(t('Checked'))
       ->setDescription(t('Last time feed was checked for new items, as Unix timestamp.'))
-      ->setSetting('default_value', 0);
+      ->setDefaultValue(0);
 
     $fields['queued'] = FieldDefinition::create('timestamp')
       ->setLabel(t('Queued'))
       ->setDescription(t('Time when this feed was queued for refresh, 0 if not queued.'))
-      ->setSetting('default_value', 0);
+      ->setDefaultValue(0);
 
     $fields['link'] = FieldDefinition::create('uri')
       ->setLabel(t('Link'))

core/modules/comment/src/Entity/Comment.php

@@ -233,18 +233,14 @@ public static function baseFieldDefinitions(EntityTypeInterface $entity_type) {
     $fields['uid'] = FieldDefinition::create('entity_reference')
       ->setLabel(t('User ID'))
       ->setDescription(t('The user ID of the comment author.'))
-      ->setSettings(array(
-        'target_type' => 'user',
-        'default_value' => 0,
-      ));
+      ->setSetting('target_type', 'user')
+      ->setDefaultValue(0);
 
     $fields['name'] = FieldDefinition::create('string')
       ->setLabel(t('Name'))
       ->setDescription(t("The comment author's name."))
-      ->setSettings(array(
-        'default_value' => '',
-        'max_length' => 60,
-      ))
+      ->setSetting('max_length', 60)
+      ->setDefaultValue('')
       ->addConstraint('CommentName', array());
 
     $fields['mail'] = FieldDefinition::create('email')
@@ -274,7 +270,7 @@ public static function baseFieldDefinitions(EntityTypeInterface $entity_type) {
     $fields['status'] = FieldDefinition::create('boolean')
       ->setLabel(t('Publishing status'))
       ->setDescription(t('A boolean indicating whether the comment is published.'))
-      ->setSetting('default_value', TRUE);
+      ->setDefaultValue(TRUE);
 
     $fields['thread'] = FieldDefinition::create('string')
       ->setLabel(t('Thread place'))

core/modules/datetime/src/Plugin/Field/FieldType/DateTimeFieldItemList.php

@@ -8,6 +8,8 @@
 namespace Drupal\datetime\Plugin\Field\FieldType;
 
 use Drupal\Core\Datetime\DrupalDateTime;
+use Drupal\Core\Entity\ContentEntityInterface;
+use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\Core\Field\FieldItemList;
 
 /**
@@ -61,14 +63,14 @@ public function defaultValuesFormSubmit(array $element, array &$form, array &$fo
   /**
    * {@inheritdoc}
    */
-  public function getDefaultValue() {
-    $default_value = parent::getDefaultValue();
+  public static function processDefaultValue($default_value, ContentEntityInterface $entity, FieldDefinitionInterface $definition) {
+    $default_value = parent::processDefaultValue($default_value, $entity, $definition);
 
     if (isset($default_value[0]['default_date']) && $default_value[0]['default_date'] == static::DEFAULT_VALUE_NOW) {
       // A default value should be in the format and timezone used for date
       // storage.
       $date = new DrupalDateTime('now', DATETIME_STORAGE_TIMEZONE);
-      $storage_format = $this->getFieldDefinition()->getSetting('datetime_type') == DateTimeItem::DATETIME_TYPE_DATE ? DATETIME_DATE_STORAGE_FORMAT: DATETIME_DATETIME_STORAGE_FORMAT;
+      $storage_format = $definition->getSetting('datetime_type') == DateTimeItem::DATETIME_TYPE_DATE ? DATETIME_DATE_STORAGE_FORMAT: DATETIME_DATETIME_STORAGE_FORMAT;
       $value = $date->format($storage_format);
       // We only provide a default value for the first item, as do all fields.
       // Otherwise, there is no way to clear out unwanted values on multiple value

core/modules/entity_reference/src/Plugin/Field/FieldType/ConfigurableEntityReferenceFieldItemList.php

@@ -8,6 +8,8 @@
 namespace Drupal\entity_reference\Plugin\Field\FieldType;
 
 use Drupal\Core\Field\EntityReferenceFieldItemList;
+use Drupal\Core\Entity\ContentEntityInterface;
+use Drupal\Core\Field\FieldDefinitionInterface;
 
 /**
  * Represents a configurable entity_reference entity field.
@@ -17,8 +19,8 @@ class ConfigurableEntityReferenceFieldItemList extends EntityReferenceFieldItemL
   /**
    * {@inheritdoc}
    */
-  protected function getDefaultValue() {
-    $default_value = parent::getDefaultValue();
+  public static function processDefaultValue($default_value, ContentEntityInterface $entity, FieldDefinitionInterface $definition) {
+    $default_value = parent::processDefaultValue($default_value, $entity, $definition);
 
     if ($default_value) {
       // Convert UUIDs to numeric IDs.
@@ -33,7 +35,7 @@ protected function getDefaultValue() {
         }
       }
       if ($uuids) {
-        $target_type = $this->getSetting('target_type');
+        $target_type = $definition->getSetting('target_type');
         $entity_ids = \Drupal::entityQuery($target_type)
           ->condition('uuid', $uuids, 'IN')
           ->execute();

core/modules/field/src/Entity/FieldInstanceConfig.php

@@ -9,7 +9,7 @@
 
 use Drupal\Component\Utility\String;
 use Drupal\Core\Config\Entity\ConfigEntityBase;
-use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Entity\ContentEntityInterface;
 use Drupal\Core\Entity\EntityStorageInterface;
 use Drupal\Core\Field\FieldDefinition;
 use Drupal\Core\Field\TypedData\FieldItemDataDefinition;
@@ -154,14 +154,10 @@ class FieldInstanceConfig extends ConfigEntityBase implements FieldInstanceConfi
    * The name of a callback function that returns default values.
    *
    * The function will be called with the following arguments:
-   * - \Drupal\Core\Entity\EntityInterface $entity
+   * - \Drupal\Core\Entity\ContentEntityInterface $entity
    *   The entity being created.
-   * - \Drupal\field\Entity\FieldConfig $field
-   *   The field object.
-   * - \Drupal\field\Entity\FieldInstanceConfig $instance
-   *   The field instance object.
-   * - string $langcode
-   *   The language of the entity being created.
+   * - \Drupal\Core\Field\FieldDefinitionInterface $definition
+   *   The field definition.
    * It should return an array of default values, in the same format as the
    * $default_value property.
    *
@@ -588,14 +584,17 @@ public function isMultiple() {
   /**
    * {@inheritdoc}
    */
-  public function getDefaultValue(EntityInterface $entity) {
-    if (!empty($this->default_value_function)) {
-      $function = $this->default_value_function;
-      return $function($entity, $this->getField(), $this, $entity->language()->id);
+  public function getDefaultValue(ContentEntityInterface $entity) {
+    // Allow custom default values function.
+    if ($function = $this->default_value_function) {
+      $value = call_user_func($function, $entity, $this);
     }
-    elseif (!empty($this->default_value)) {
-      return $this->default_value;
+    else {
+      $value = $this->default_value;
     }
+    // Allow the field type to process default values.
+    $field_item_list_class = $this->getClass();
+    return $field_item_list_class::processDefaultValue($value, $entity, $this);
   }
 
   /**

core/modules/field/src/Tests/FieldAttachStorageTest.php

@@ -220,7 +220,7 @@ function testFieldAttachSaveEmptyDataDefaultValue() {
 
     // Verify that fields are populated with default values.
     $entity_init = entity_create($entity_type, array('id' => 1, 'revision_id' => 1));
-    $default = field_test_default_value($entity_init, $this->field, $this->instance);
+    $default = field_test_default_value($entity_init, $this->instance);
     $this->assertEqual($entity_init->{$this->field_name}->getValue(), $default, 'Default field value correctly populated.');
 
     // Insert: Field is NULL.

core/modules/field/tests/modules/field_test/field_test.field.inc

@@ -5,7 +5,7 @@
  * Defines a field type and its formatters and widgets.
  */
 
-use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Entity\ContentEntityInterface;
 use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\Core\Field\FieldItemListInterface;
 use Drupal\Core\Session\AccountInterface;
@@ -31,7 +31,7 @@ function field_test_field_config_update_forbid(FieldConfigInterface $field, Fiel
 /**
  * Sample 'default value' callback.
  */
-function field_test_default_value(EntityInterface $entity, $field, $instance) {
+function field_test_default_value(ContentEntityInterface $entity, FieldDefinitionInterface $definition) {
   return array(array('value' => 99));
 }
 

core/modules/node/src/Entity/Node.php

@@ -357,7 +357,7 @@ public static function baseFieldDefinitions(EntityTypeInterface $entity_type) {
       ->setRequired(TRUE)
       ->setTranslatable(TRUE)
       ->setRevisionable(TRUE)
-      ->setSetting('default_value', '')
+      ->setDefaultValue('')
       ->setSetting('max_length', 255)
       ->setDisplayOptions('view', array(
         'label' => 'hidden',
@@ -453,11 +453,11 @@ public static function bundleFieldDefinitions(EntityTypeInterface $entity_type,
 
     $options = $node_type->getModuleSettings('node')['options'];
     $fields['status'] = clone $base_field_definitions['status'];
-    $fields['status']->setSetting('default_value', !empty($options['status']) ? NODE_PUBLISHED : NODE_NOT_PUBLISHED);
+    $fields['status']->setDefaultValue(!empty($options['status']) ? NODE_PUBLISHED : NODE_NOT_PUBLISHED);
     $fields['promote'] = clone $base_field_definitions['promote'];
-    $fields['promote']->setSetting('default_value', !empty($options['promote']) ? NODE_PROMOTED : NODE_NOT_PROMOTED);
+    $fields['promote']->setDefaultValue(!empty($options['promote']) ? NODE_PROMOTED : NODE_NOT_PROMOTED);
     $fields['sticky'] = clone $base_field_definitions['sticky'];
-    $fields['sticky']->setSetting('default_value', !empty($options['sticky']) ? NODE_STICKY : NODE_NOT_STICKY);
+    $fields['sticky']->setDefaultValue(!empty($options['sticky']) ? NODE_STICKY : NODE_NOT_STICKY);
 
     return $fields;
   }

core/modules/serialization/src/Tests/EntitySerializationTest.php

@@ -8,7 +8,6 @@
 namespace Drupal\serialization\Tests;
 
 use Drupal\Core\Language\LanguageInterface;
-use Symfony\Component\Serializer\Serializer;
 use Drupal\Component\Utility\String;
 
 /**

core/modules/shortcut/src/Entity/Shortcut.php

@@ -174,7 +174,7 @@ public static function baseFieldDefinitions(EntityTypeInterface $entity_type) {
       ->setDescription(t('The name of the shortcut.'))
       ->setRequired(TRUE)
       ->setTranslatable(TRUE)
-      ->setSetting('default_value', '')
+      ->setDefaultValue('')
       ->setSetting('max_length', 255)
       ->setDisplayOptions('form', array(
         'type' => 'string',

core/modules/system/src/Tests/Entity/EntityFieldDefaultValueTest.php

@@ -59,4 +59,15 @@ protected function assertDefaultValues($entity_type) {
     $this->assertTrue(Uuid::isValid($entity->uuid->value), String::format('%entity_type: Default UUID', array('%entity_type' => $entity_type)));
     $this->assertEqual($entity->name->getValue(), array(0 => array('value' => NULL)), 'Field has one empty value by default.');
   }
+
+  /**