comparison core/modules/field/field.api.php @ 0:4c8ae668cc8c

Initial import (non-working)

+<?php
+
+/**
+ * @file
+ * Field API documentation.
+ */
+
+/**
+ * @addtogroup hooks
+ * @{
+ */
+
+/**
+ * @defgroup field_types 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
+ * @link plugin_api Plugin API topic @endlink for more information on how to
+ * define plugins.
+ *
+ * The Field Types API also defines two kinds of pluggable handlers: widgets
+ * and formatters. @link field_widget Widgets @endlink specify how the field
+ * appears in edit forms, while @link field_formatter formatters @endlink
+ * specify how the field appears in displayed entities.
+ *
+ * See @link field Field API @endlink for information about the other parts of
+ * the Field API.
+ *
+ * @see field
+ * @see field_widget
+ * @see field_formatter
+ * @see plugin_api
+ */
+
+
+/**
+ * Perform alterations on Field API field types.
+ *
+ * @param $info
+ *   Array of information on field types as collected by the "field type" plugin
+ *   manager.
+ */
+function hook_field_info_alter(&$info) {
+  // Change the default widget for fields of type 'foo'.
+  if (isset($info['foo'])) {
+    $info['foo']['default widget'] = 'mymodule_widget';
+  }
+}
+
+/**
+ * Forbid a field storage update from occurring.
+ *
+ * Any module may forbid any update for any reason. For example, the
+ * field's storage module might forbid an update if it would change
+ * the storage schema while data for the field exists. A field type
+ * module might forbid an update if it would change existing data's
+ * semantics, or if there are external dependencies on field settings
+ * that cannot be updated.
+ *
+ * To forbid the update from occurring, throw a
+ * \Drupal\Core\Entity\Exception\FieldStorageDefinitionUpdateForbiddenException.
+ *
+ * @param \Drupal\field\FieldStorageConfigInterface $field_storage
+ *   The field storage as it will be post-update.
+ * @param \Drupal\field\FieldStorageConfigInterface $prior_field_storage
+ *   The field storage as it is pre-update.
+ *
+ * @see entity_crud
+ */
+function hook_field_storage_config_update_forbid(\Drupal\field\FieldStorageConfigInterface $field_storage, \Drupal\field\FieldStorageConfigInterface $prior_field_storage) {
+  if ($field_storage->module == 'options' && $field_storage->hasData()) {
+    // Forbid any update that removes allowed values with actual data.
+    $allowed_values = $field_storage->getSetting('allowed_values');
+    $prior_allowed_values = $prior_field_storage->getSetting('allowed_values');
+    $lost_keys = array_keys(array_diff_key($prior_allowed_values, $allowed_values));
+    if (_options_values_in_use($field_storage->getTargetEntityTypeId(), $field_storage->getName(), $lost_keys)) {
+      throw new \Drupal\Core\Entity\Exception\FieldStorageDefinitionUpdateForbiddenException(t('A list field (@field_name) with existing data cannot have its keys changed.', ['@field_name' => $field_storage->getName()]));
+    }
+  }
+}
+
+/**
+ * @} End of "defgroup field_types".
+ */
+
+/**
+ * @defgroup field_widget Field Widget API
+ * @{
+ * Define Field API widget types.
+ *
+ * Field API widgets specify how fields are displayed in edit forms. Fields of a
+ * given @link field_types field type @endlink may be edited using more than one
+ * widget. In this case, the Field UI module allows the site builder to choose
+ * which widget to use.
+ *
+ * Widgets are Plugins managed by the
+ * \Drupal\Core\Field\WidgetPluginManager class. A widget is a plugin annotated
+ * with class \Drupal\Core\Field\Annotation\FieldWidget that implements
+ * \Drupal\Core\Field\WidgetInterface (in most cases, by
+ * subclassing \Drupal\Core\Field\WidgetBase). Widget plugins need to be in the
+ * namespace \Drupal\{your_module}\Plugin\Field\FieldWidget.
+ *
+ * Widgets are @link form_api Form API @endlink elements with additional
+ * processing capabilities. The methods of the WidgetInterface object are
+ * typically called by respective methods in the
+ * \Drupal\Core\Entity\Entity\EntityFormDisplay class.
+ *
+ * @see field
+ * @see field_types
+ * @see field_formatter
+ * @see plugin_api
+ */
+
+/**
+ * Perform alterations on Field API widget types.
+ *
+ * @param array $info
+ *   An array of information on existing widget types, as collected by the
+ *   annotation discovery mechanism.
+ */
+function hook_field_widget_info_alter(array &$info) {
+  // Let a new field type re-use an existing widget.
+  $info['options_select']['field_types'][] = 'my_field_type';
+}
+
+/**
+ * Alter forms for field widgets provided by other modules.
+ *
+ * @param $element
+ *   The field widget form element as constructed by hook_field_widget_form().
+ * @param $form_state
+ *   The current state of the form.
+ * @param $context
+ *   An associative array containing the following key-value pairs:
+ *   - form: The form structure to which widgets are being attached. This may be
+ *     a full form structure, or a sub-element of a larger form.
+ *   - widget: The widget plugin instance.
+ *   - items: The field values, as a
+ *     \Drupal\Core\Field\FieldItemListInterface object.
+ *   - delta: The order of this item in the array of subelements (0, 1, 2, etc).
+ *   - default: A boolean indicating whether the form is being shown as a dummy
+ *     form to set default values.
+ *
+ * @see \Drupal\Core\Field\WidgetBase::formSingleElement()
+ * @see hook_field_widget_WIDGET_TYPE_form_alter()
+ */
+function hook_field_widget_form_alter(&$element, \Drupal\Core\Form\FormStateInterface $form_state, $context) {
+  // Add a css class to widget form elements for all fields of type mytype.
+  $field_definition = $context['items']->getFieldDefinition();
+  if ($field_definition->getType() == 'mytype') {
+    // Be sure not to overwrite existing attributes.
+    $element['#attributes']['class'][] = 'myclass';
+  }
+}
+
+/**
+ * Alter widget forms for a specific widget provided by another module.
+ *
+ * Modules can implement hook_field_widget_WIDGET_TYPE_form_alter() to modify a
+ * specific widget form, rather than using hook_field_widget_form_alter() and
+ * checking the widget type.
+ *
+ * @param $element
+ *   The field widget form element as constructed by hook_field_widget_form().
+ * @param $form_state
+ *   The current state of the form.
+ * @param $context
+ *   An associative array. See hook_field_widget_form_alter() for the structure
+ *   and content of the array.
+ *
+ * @see \Drupal\Core\Field\WidgetBase::formSingleElement()
+ * @see hook_field_widget_form_alter()
+ */
+function hook_field_widget_WIDGET_TYPE_form_alter(&$element, \Drupal\Core\Form\FormStateInterface $form_state, $context) {
+  // Code here will only act on widgets of type WIDGET_TYPE.  For example,
+  // hook_field_widget_mymodule_autocomplete_form_alter() will only act on
+  // widgets of type 'mymodule_autocomplete'.
+  $element['#autocomplete_route_name'] = 'mymodule.autocomplete_route';
+}
+
+/**
+ * @} End of "defgroup field_widget".
+ */
+
+
+/**
+ * @defgroup field_formatter Field Formatter API
+ * @{
+ * Define Field API formatter types.
+ *
+ * Field API formatters specify how fields are displayed when the entity to
+ * which the field is attached is displayed. Fields of a given
+ * @link field_types field type @endlink may be displayed using more than one
+ * formatter. In this case, the Field UI module allows the site builder to
+ * choose which formatter to use.
+ *
+ * Formatters are Plugins managed by the
+ * \Drupal\Core\Field\FormatterPluginManager class. A formatter is a plugin
+ * annotated with class \Drupal\Core\Field\Annotation\FieldFormatter that
+ * implements \Drupal\Core\Field\FormatterInterface (in most cases, by
+ * subclassing \Drupal\Core\Field\FormatterBase). Formatter plugins need to be
+ * in the namespace \Drupal\{your_module}\Plugin\Field\FieldFormatter.
+ *
+ * @see field
+ * @see field_types
+ * @see field_widget
+ * @see plugin_api
+ */
+
+/**
+ * Perform alterations on Field API formatter types.
+ *
+ * @param array $info
+ *   An array of information on existing formatter types, as collected by the
+ *   annotation discovery mechanism.
+ */
+function hook_field_formatter_info_alter(array &$info) {
+  // Let a new field type re-use an existing formatter.
+  $info['text_default']['field_types'][] = 'my_field_type';
+}
+
+/**
+ * @} End of "defgroup field_formatter".
+ */
+
+/**
+ * Returns the maximum weight for the entity components handled by the module.
+ *
+ * Field API takes care of fields and 'extra_fields'. This hook is intended for
+ * third-party modules adding other entity components (e.g. field_group).
+ *
+ * @param string $entity_type
+ *   The type of entity; e.g. 'node' or 'user'.
+ * @param string $bundle
+ *   The bundle name.
+ * @param string $context
+ *   The context for which the maximum weight is requested. Either 'form' or
+ *   'display'.
+ * @param string $context_mode
+ *   The view or form mode name.
+ *
+ * @return int
+ *   The maximum weight of the entity's components, or NULL if no components
+ *   were found.
+ *
+ * @ingroup field_info
+ */
+function hook_field_info_max_weight($entity_type, $bundle, $context, $context_mode) {
+  $weights = [];
+
+  foreach (my_module_entity_additions($entity_type, $bundle, $context, $context_mode) as $addition) {
+    $weights[] = $addition['weight'];
+  }
+
+  return $weights ? max($weights) : NULL;
+}
+
+/**
+ * @addtogroup field_purge
+ * @{
+ */
+
+/**
+ * Acts when a field storage definition is being purged.
+ *
+ * In field_purge_field_storage(), after the storage definition has been removed
+ * from the system, the entity storage has purged stored field data, and the
+ * field definitions cache has been cleared, this hook is invoked on all modules
+ * to allow them to respond to the field storage being purged.
+ *
+ * @param $field_storage \Drupal\field\Entity\FieldStorageConfig
+ *   The field storage being purged.
+ */
+function hook_field_purge_field_storage(\Drupal\field\Entity\FieldStorageConfig $field_storage) {
+  db_delete('my_module_field_storage_info')
+    ->condition('uuid', $field_storage->uuid())
+    ->execute();
+}
+
+/**
+ * Acts when a field is being purged.
+ *
+ * In field_purge_field(), after the field definition has been removed
+ * from the system, the entity storage has purged stored field data, and the
+ * field info cache has been cleared, this hook is invoked on all modules to
+ * allow them to respond to the field being purged.
+ *
+ * @param $field
+ *   The field being purged.
+ */
+function hook_field_purge_field(\Drupal\field\Entity\FieldConfig $field) {
+  db_delete('my_module_field_info')
+    ->condition('id', $field->id())
+    ->execute();
+}
+
+/**
+ * @} End of "addtogroup field_purge".
+ */
+
+/**
+ * @} End of "addtogroup hooks".
+ */