class FormErrorHandler in Drupal 8

Produces inline form errors.

Hierarchy

• class \Drupal\Core\Form\FormErrorHandler implements FormErrorHandlerInterface uses MessengerTrait
  • class \Drupal\inline_form_errors\FormErrorHandler uses StringTranslationTrait

1 file declares its use of FormErrorHandler

FormErrorHandlerTest.php in core/modules/inline_form_errors/tests/src/Unit/FormErrorHandlerTest.php

File

core/modules/inline_form_errors/src/FormErrorHandler.php, line 19

Namespace

Drupal\inline_form_errors

class FormErrorHandler extends CoreFormErrorHandler {
  use StringTranslationTrait;

  /**
   * The renderer service.
   *
   * @var \Drupal\Core\Render\RendererInterface
   */
  protected $renderer;

  /**
   * The messenger.
   *
   * @var \Drupal\Core\Messenger\MessengerInterface
   */
  protected $messenger;

  /**
   * Constructs a new FormErrorHandler.
   *
   * @param \Drupal\Core\StringTranslation\TranslationInterface $string_translation
   *   The string translation service.
   * @param \Drupal\Core\Render\RendererInterface $renderer
   *   The renderer service.
   * @param \Drupal\Core\Messenger\MessengerInterface $messenger
   *   The messenger.
   */
  public function __construct(TranslationInterface $string_translation, RendererInterface $renderer, MessengerInterface $messenger) {
    $this->stringTranslation = $string_translation;
    $this->renderer = $renderer;
    $this->messenger = $messenger;
  }

  /**
   * Loops through and displays all form errors.
   *
   * To disable inline form errors for an entire form set the
   * #disable_inline_form_errors property to TRUE on the top level of the $form
   * array:
   * @code
   * $form['#disable_inline_form_errors'] = TRUE;
   * @endcode
   * This should only be done when another appropriate accessibility strategy is
   * in place.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   */
  protected function displayErrorMessages(array $form, FormStateInterface $form_state) {

    // Skip generating inline form errors when opted out.
    if (!empty($form['#disable_inline_form_errors'])) {
      parent::displayErrorMessages($form, $form_state);
      return;
    }
    $error_links = [];
    $errors = $form_state
      ->getErrors();

    // Loop through all form errors and check if we need to display a link.
    foreach ($errors as $name => $error) {
      $form_element = FormElementHelper::getElementByName($name, $form);
      $title = FormElementHelper::getElementTitle($form_element);

      // Only show links to erroneous elements that are visible.
      $is_visible_element = Element::isVisibleElement($form_element);

      // Only show links for elements that have a title themselves or have
      // children with a title.
      $has_title = !empty($title);

      // Only show links for elements with an ID.
      $has_id = !empty($form_element['#id']);

      // Do not show links to elements with suppressed messages. Most often
      // their parent element is used for inline errors.
      if (!empty($form_element['#error_no_message'])) {
        unset($errors[$name]);
      }
      elseif ($is_visible_element && $has_title && $has_id) {
        $error_links[] = Link::fromTextAndUrl($title, Url::fromRoute('<none>', [], [
          'fragment' => $form_element['#id'],
          'external' => TRUE,
        ]))
          ->toRenderable();
        unset($errors[$name]);
      }
    }

    // Set normal error messages for all remaining errors.
    foreach ($errors as $error) {
      $this->messenger
        ->addError($error);
    }
    if (!empty($error_links)) {
      $render_array = [
        [
          '#markup' => $this
            ->formatPlural(count($error_links), '1 error has been found: ', '@count errors have been found: '),
        ],
        [
          '#theme' => 'item_list',
          '#items' => $error_links,
          '#context' => [
            'list_style' => 'comma-list',
          ],
        ],
      ];
      $message = $this->renderer
        ->renderPlain($render_array);
      $this->messenger
        ->addError($message);
    }
  }

}

Members

Name	Modifiers	Type	Description	Overrides
FormErrorHandler::$messenger	protected	property	The messenger. Overrides MessengerTrait::$messenger
FormErrorHandler::$renderer	protected	property	The renderer service.
FormErrorHandler::displayErrorMessages	protected	function	Loops through and displays all form errors. Overrides FormErrorHandler::displayErrorMessages
FormErrorHandler::handleFormErrors	public	function	Handles form errors after form validation. Overrides FormErrorHandlerInterface::handleFormErrors
FormErrorHandler::setElementErrorsFromFormState	protected	function	Stores errors and a list of child element errors directly on each element.
FormErrorHandler::__construct	public	function	Constructs a new FormErrorHandler.
MessengerTrait::messenger	public	function	Gets the messenger.	29
MessengerTrait::setMessenger	public	function	Sets the messenger.
StringTranslationTrait::$stringTranslation	protected	property	The string translation service.	1
StringTranslationTrait::formatPlural	protected	function	Formats a string containing a count of items.
StringTranslationTrait::getNumberOfPlurals	protected	function	Returns the number of plurals supported by a given language.
StringTranslationTrait::getStringTranslation	protected	function	Gets the string translation service.
StringTranslationTrait::setStringTranslation	public	function	Sets the string translation service to use.	2
StringTranslationTrait::t	protected	function	Translates a string to the current language or to a given language.