Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\Core\Field;
Chris@0: 
Chris@0: use Drupal\Core\Form\FormStateInterface;
Chris@0: use Symfony\Component\Validator\ConstraintViolationInterface;
Chris@0: 
Chris@0: /**
Chris@0:  * Interface definition for field widget plugins.
Chris@0:  *
Chris@0:  * This interface details the methods that most plugin implementations will want
Chris@0:  * to override. See Drupal\Core\Field\WidgetBaseInterface for base
Chris@0:  * wrapping methods that should most likely be inherited directly from
Chris@0:  * Drupal\Core\Field\WidgetBase..
Chris@0:  *
Chris@0:  * @ingroup field_widget
Chris@0:  */
Chris@0: interface WidgetInterface extends WidgetBaseInterface {
Chris@0: 
Chris@0:   /**
Chris@0:    * Returns a form to configure settings for the widget.
Chris@0:    *
Chris@0:    * Invoked from \Drupal\field_ui\Form\EntityDisplayFormBase to allow
Chris@0:    * administrators to configure the widget. The field_ui module takes care of
Chris@0:    * handling submitted form values.
Chris@0:    *
Chris@0:    * @param array $form
Chris@0:    *   The form where the settings form is being included in.
Chris@0:    * @param \Drupal\Core\Form\FormStateInterface $form_state
Chris@0:    *   The current state of the form.
Chris@0:    *
Chris@0:    * @return array
Chris@0:    *   The form definition for the widget settings.
Chris@0:    */
Chris@0:   public function settingsForm(array $form, FormStateInterface $form_state);
Chris@0: 
Chris@0:   /**
Chris@0:    * Returns a short summary for the current widget settings.
Chris@0:    *
Chris@0:    * If an empty result is returned, a UI can still be provided to display
Chris@0:    * a settings form in case the widget has configurable settings.
Chris@0:    *
Chris@0:    * @return array
Chris@0:    *   A short summary of the widget settings.
Chris@0:    */
Chris@0:   public function settingsSummary();
Chris@0: 
Chris@0:   /**
Chris@0:    * Returns the form for a single field widget.
Chris@0:    *
Chris@0:    * Field widget form elements should be based on the passed-in $element, which
Chris@0:    * contains the base form element properties derived from the field
Chris@0:    * configuration.
Chris@0:    *
Chris@0:    * The BaseWidget methods will set the weight, field name and delta values for
Chris@0:    * each form element. If there are multiple values for this field, the
Chris@0:    * formElement() method will be called as many times as needed.
Chris@0:    *
Chris@0:    * Other modules may alter the form element provided by this function using
Chris@0:    * hook_field_widget_form_alter() or
Chris@0:    * hook_field_widget_WIDGET_TYPE_form_alter().
Chris@0:    *
Chris@0:    * The FAPI element callbacks (such as #process, #element_validate,
Chris@0:    * #value_callback, etc.) used by the widget do not have access to the
Chris@0:    * original $field_definition passed to the widget's constructor. Therefore,
Chris@0:    * if any information is needed from that definition by those callbacks, the
Chris@0:    * widget implementing this method, or a
Chris@0:    * hook_field_widget[_WIDGET_TYPE]_form_alter() implementation, must extract
Chris@0:    * the needed properties from the field definition and set them as ad-hoc
Chris@0:    * $element['#custom'] properties, for later use by its element callbacks.
Chris@0:    *
Chris@0:    * @param \Drupal\Core\Field\FieldItemListInterface $items
Chris@0:    *   Array of default values for this field.
Chris@0:    * @param int $delta
Chris@0:    *   The order of this item in the array of sub-elements (0, 1, 2, etc.).
Chris@0:    * @param array $element
Chris@0:    *   A form element array containing basic properties for the widget:
Chris@0:    *   - #field_parents: The 'parents' space for the field in the form. Most
Chris@0:    *       widgets can simply overlook this property. This identifies the
Chris@0:    *       location where the field values are placed within
Chris@0:    *       $form_state->getValues(), and is used to access processing
Chris@0:    *       information for the field through the getWidgetState() and
Chris@0:    *       setWidgetState() methods.
Chris@0:    *   - #title: The sanitized element label for the field, ready for output.
Chris@0:    *   - #description: The sanitized element description for the field, ready
Chris@0:    *     for output.
Chris@0:    *   - #required: A Boolean indicating whether the element value is required;
Chris@0:    *     for required multiple value fields, only the first widget's values are
Chris@0:    *     required.
Chris@0:    *   - #delta: The order of this item in the array of sub-elements; see $delta
Chris@0:    *     above.
Chris@0:    * @param array $form
Chris@0:    *   The form structure where widgets are being attached to. This might be a
Chris@0:    *   full form structure, or a sub-element of a larger form.
Chris@0:    * @param \Drupal\Core\Form\FormStateInterface $form_state
Chris@0:    *   The current state of the form.
Chris@0:    *
Chris@0:    * @return array
Chris@0:    *   The form elements for a single widget for this field.
Chris@0:    *
Chris@0:    * @see hook_field_widget_form_alter()
Chris@0:    * @see hook_field_widget_WIDGET_TYPE_form_alter()
Chris@0:    */
Chris@0:   public function formElement(FieldItemListInterface $items, $delta, array $element, array &$form, FormStateInterface $form_state);
Chris@0: 
Chris@0:   /**
Chris@0:    * Assigns a field-level validation error to the right widget sub-element.
Chris@0:    *
Chris@0:    * Depending on the widget's internal structure, a field-level validation
Chris@0:    * error needs to be flagged on the right sub-element.
Chris@0:    *
Chris@0:    * @param array $element
Chris@0:    *   An array containing the form element for the widget, as generated by
Chris@0:    *   formElement().
Chris@0:    * @param \Symfony\Component\Validator\ConstraintViolationInterface $violation
Chris@0:    *   A constraint violation reported during the validation phase.
Chris@0:    * @param array $form
Chris@0:    *   The form structure where field elements are attached to. This might be a
Chris@0:    *   full form structure, or a sub-element of a larger form.
Chris@0:    * @param \Drupal\Core\Form\FormStateInterface $form_state
Chris@0:    *   The current state of the form.
Chris@0:    *
Chris@0:    * @return array|bool
Chris@0:    *   The element on which the error should be flagged, or FALSE to completely
Chris@0:    *   ignore the violation (use with care!).
Chris@0:    */
Chris@0:   public function errorElement(array $element, ConstraintViolationInterface $violation, array $form, FormStateInterface $form_state);
Chris@0: 
Chris@0:   /**
Chris@0:    * Massages the form values into the format expected for field values.
Chris@0:    *
Chris@0:    * @param array $values
Chris@0:    *   The submitted form values produced by the widget.
Chris@0:    *   - If the widget does not manage multiple values itself, the array holds
Chris@0:    *     the values generated by the multiple copies of the $element generated
Chris@0:    *     by the formElement() method, keyed by delta.
Chris@0:    *   - If the widget manages multiple values, the array holds the values
Chris@0:    *     of the form element generated by the formElement() method.
Chris@0:    * @param array $form
Chris@0:    *   The form structure where field elements are attached to. This might be a
Chris@0:    *   full form structure, or a sub-element of a larger form.
Chris@0:    * @param \Drupal\Core\Form\FormStateInterface $form_state
Chris@0:    *   The form state.
Chris@0:    *
Chris@0:    * @return array
Chris@0:    *   An array of field values, keyed by delta.
Chris@0:    */
Chris@0:   public function massageFormValues(array $values, array $form, FormStateInterface $form_state);
Chris@0: 
Chris@0:   /**
Chris@0:    * Returns if the widget can be used for the provided field.
Chris@0:    *
Chris@0:    * @param \Drupal\Core\Field\FieldDefinitionInterface $field_definition
Chris@0:    *   The field definition that should be checked.
Chris@0:    *
Chris@0:    * @return bool
Chris@0:    *   TRUE if the widget can be used, FALSE otherwise.
Chris@0:    */
Chris@0:   public static function isApplicable(FieldDefinitionInterface $field_definition);
Chris@0: 
Chris@0: }