YamlFormSubmissionForm.php in YAML Form 8

Namespace

Drupal\yamlform

File

src/YamlFormSubmissionForm.php

<?php

namespace Drupal\yamlform;

use Drupal\Component\Utility\NestedArray;
use Drupal\Core\Cache\Cache;
use Drupal\Core\Entity\EntityInterface;
use Drupal\Core\Entity\EntityManagerInterface;
use Drupal\Core\Entity\ContentEntityForm;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Render\Element;
use Drupal\Core\Routing\TrustedRedirectResponse;
use Drupal\Core\Url;
use Drupal\yamlform\Controller\YamlFormController;
use Drupal\yamlform\Utility\YamlFormArrayHelper;
use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * Provides a form to collect and edit submissions.
 */
class YamlFormSubmissionForm extends ContentEntityForm {
  use YamlFormDialogTrait;

  /**
   * The form element (plugin) manager.
   *
   * @var \Drupal\yamlform\YamlFormElementManagerInterface
   */
  protected $elementManager;

  /**
   * The form submission storage.
   *
   * @var \Drupal\yamlform\YamlFormSubmissionStorageInterface
   */
  protected $storage;

  /**
   * Form request handler.
   *
   * @var \Drupal\yamlform\YamlFormRequestInterface
   */
  protected $requestHandler;

  /**
   * The form third party settings manager.
   *
   * @var \Drupal\yamlform\YamlFormThirdPartySettingsManagerInterface
   */
  protected $thirdPartySettingsManager;

  /**
   * The form message manager.
   *
   * @var \Drupal\yamlform\YamlFormMessageManagerInterface
   */
  protected $messageManager;

  /**
   * The token manager.
   *
   * @var \Drupal\yamlform\YamlFormTranslationManagerInterface
   */
  protected $tokenManager;

  /**
   * The form settings.
   *
   * @var array
   */
  protected $settings;

  /**
   * The form submission.
   *
   * @var \Drupal\yamlform\YamlFormSubmissionInterface
   */
  protected $entity;

  /**
   * The source entity.
   *
   * @var \Drupal\Core\Entity\EntityInterface
   */
  protected $sourceEntity;

  /**
   * Constructs a YamlFormSubmissionForm object.
   *
   * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
   *   The entity manager.
   * @param \Drupal\yamlform\YamlFormRequestInterface $request_handler
   *   The form request handler.
   * @param \Drupal\yamlform\YamlFormElementManagerInterface $element_manager
   *   The form element manager.
   * @param \Drupal\yamlform\YamlFormThirdPartySettingsManagerInterface $third_party_settings_manager
   *   The form third party settings manager.
   * @param \Drupal\yamlform\YamlFormMessageManagerInterface $message_manager
   *   The form message manager.
   * @param \Drupal\yamlform\YamlFormTokenManagerInterface $token_manager
   *   The token manager.
   */
  public function __construct(EntityManagerInterface $entity_manager, YamlFormRequestInterface $request_handler, YamlFormElementManagerInterface $element_manager, YamlFormThirdPartySettingsManagerInterface $third_party_settings_manager, YamlFormMessageManagerInterface $message_manager, YamlFormTokenManagerInterface $token_manager) {
    parent::__construct($entity_manager);
    $this->requestHandler = $request_handler;
    $this->elementManager = $element_manager;
    $this->storage = $this->entityManager
      ->getStorage('yamlform_submission');
    $this->thirdPartySettingsManager = $third_party_settings_manager;
    $this->messageManager = $message_manager;
    $this->tokenManager = $token_manager;
  }

  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container) {
    return new static($container
      ->get('entity.manager'), $container
      ->get('yamlform.request'), $container
      ->get('plugin.manager.yamlform.element'), $container
      ->get('yamlform.third_party_settings_manager'), $container
      ->get('yamlform.message_manager'), $container
      ->get('yamlform.token_manager'));
  }

  /**
   * {@inheritdoc}
   */
  public function setEntity(EntityInterface $entity) {

    /** @var \Drupal\yamlform\YamlFormInterface $yamlform */
    $yamlform = $entity
      ->getYamlForm();
    $this->sourceEntity = $this->requestHandler
      ->getCurrentSourceEntity([
      'yamlform',
      'yamlform_submission',
    ]);
    if ($yamlform
      ->getSetting('token_update') && ($token = $this
      ->getRequest()->query
      ->get('token'))) {
      if ($yamlform_submissions_token = $this->storage
        ->loadByProperties([
        'token' => $token,
      ])) {
        $entity = reset($yamlform_submissions_token);
      }
    }
    elseif ($yamlform_submission_draft = $this->storage
      ->loadDraft($yamlform, $this->sourceEntity, $this
      ->currentUser())) {
      $entity = $yamlform_submission_draft;
    }
    $this->messageManager
      ->setYamlFormSubmission($entity);
    $this->messageManager
      ->setSourceEntity($this->sourceEntity);
    return parent::setEntity($entity);
  }

  /**
   * {@inheritdoc}
   */
  public function buildForm(array $form, FormStateInterface $form_state) {

    /* @var $yamlform_submission \Drupal\yamlform\YamlFormSubmissionInterface */
    $yamlform_submission = $this
      ->getEntity();
    $yamlform = $this
      ->getYamlForm();

    // This submission form is based on the current URL, and hence it depends
    // on the 'url' cache context.
    $form['#cache']['contexts'][] = 'url';

    // Add this form and the form settings to the cache tags.
    $form['#cache']['tags'][] = 'config:yamlform.settings';

    // Add the form as a cacheable dependency.
    \Drupal::service('renderer')
      ->addCacheableDependency($form, $this
      ->getYamlForm());

    // Display status messages.
    $this
      ->displayMessages($form, $form_state);

    // Build the form.
    $form = parent::buildForm($form, $form_state);

    // Alter form via form handler.
    $this
      ->getYamlForm()
      ->invokeHandlers('alterForm', $form, $form_state, $yamlform_submission);

    // Call custom form alter hook.
    $form_id = $this
      ->getFormId();
    $this->thirdPartySettingsManager
      ->alter('yamlform_submission_form', $form, $form_state, $form_id);
    return $form;
  }

  /**
   * {@inheritdoc}
   */
  public function form(array $form, FormStateInterface $form_state) {

    // Check for a custom form, track it, and return it.
    if ($custom_form = $this
      ->getCustomForm($form, $form_state)) {
      $custom_form['#custom_form'] = TRUE;
      return $custom_form;
    }

    /* @var $yamlform_submission \Drupal\yamlform\YamlFormSubmissionInterface */
    $yamlform_submission = $this
      ->getEntity();
    $yamlform = $this
      ->getYamlForm();
    $form = parent::form($form, $form_state);

    /* Information */

    // Prepend form submission data using the default view without the data.
    if (!$yamlform_submission
      ->isNew() && !$yamlform_submission
      ->isDraft()) {
      $form['navigation'] = [
        '#theme' => 'yamlform_submission_navigation',
        '#yamlform_submission' => $yamlform_submission,
        '#weight' => -20,
      ];
      $form['information'] = [
        '#theme' => 'yamlform_submission_information',
        '#yamlform_submission' => $yamlform_submission,
        '#source_entity' => $this->sourceEntity,
        '#weight' => -19,
      ];
    }

    /* Data */

    // Get and prepopulate (via query string) submission data.
    $data = $yamlform_submission
      ->getData();
    $this
      ->prepopulateData($data);

    /* Elements */

    // Get form elements.
    $elements = $yamlform_submission
      ->getYamlForm()
      ->getElementsInitialized();

    // Populate form elements with form submission data.
    $this
      ->populateElements($elements, $data);

    // Prepare form elements.
    $this
      ->prepareElements($elements, $form, $form_state);

    // Add wizard progress tracker to the form.
    $current_page = $this
      ->getCurrentPage($form, $form_state);
    if ($current_page && $this
      ->getYamlFormSetting('wizard_progress_bar') || $this
      ->getYamlFormSetting('wizard_progress_pages') || $this
      ->getYamlFormSetting('wizard_progress_percentage')) {
      $form['progress'] = [
        '#theme' => 'yamlform_progress',
        '#yamlform' => $this
          ->getYamlForm(),
        '#current_page' => $current_page,
      ];
    }

    // Append elements to the form.
    $form['elements'] = $elements;

    // Pages: Set current wizard or preview page.
    $this
      ->displayCurrentPage($form, $form_state);

    /* Form  */

    // Move all $elements properties to the $form.
    $this
      ->setFormPropertiesFromElements($form, $elements);

    // Default: Add CSS and JS.
    // @see https://www.drupal.org/node/2274843#inline
    $form['#attached']['library'][] = 'yamlform/yamlform.form';

    // Assets: Add custom CSS and JS.
    // @see yamlform_css_alter()
    // @see yamlform_js_alter()
    $assets = [
      'css' => $yamlform
        ->getCss(),
      'javascript' => $yamlform
        ->getJavaScript(),
    ];
    foreach ($assets as $type => $value) {
      if ($value) {
        $form['#attached']['library'][] = "yamlform/yamlform.assets.{$type}";
        $form['#attached']['drupalSettings']['yamlform']['assets'][$type][$yamlform
          ->id()] = md5($value);
      }
    }

    // Attach disable back button.
    if ($this
      ->getYamlFormSetting('form_disable_back')) {
      $form['#attached']['library'][] = 'yamlform/yamlform.form.disable_back';
    }

    // Unsaved: Add unsaved message.
    if ($this
      ->getYamlFormSetting('form_unsaved')) {
      $form['#attributes']['class'][] = 'js-yamlform-unsaved';
      $form['#attached']['library'][] = 'yamlform/yamlform.form.unsaved';
      $current_page = $this
        ->getCurrentPage($form, $form_state);
      if ($current_page && $current_page != $this
        ->getFirstPage($form, $form_state)) {
        $form['#attributes']['data-yamlform-unsaved'] = TRUE;
      }
    }

    // Novalidate: Add novalidate attribute to form if client side validation disabled.
    if ($this
      ->getYamlFormSetting('form_novalidate')) {
      $form['#attributes']['novalidate'] = 'novalidate';
    }

    // Details toggle: Display collapse/expand all details link.
    if ($this
      ->getYamlFormSetting('form_details_toggle')) {
      $form['#attributes']['class'][] = 'yamlform-details-toggle';
      $form['#attached']['library'][] = 'yamlform/yamlform.element.details.toggle';
    }

    // Autofocus: Add autofocus class to form.
    if ($this->entity
      ->isNew() && $this
      ->getYamlFormSetting('form_autofocus')) {
      $form['#attributes']['class'][] = 'js-yamlform-autofocus';
    }

    // Details save: Attach details element save open/close library.
    // This ensures that the library will be loaded even if the form is
    // used as a block or a node.
    if ($this
      ->config('yamlform.settings')
      ->get('ui.details_save')) {
      $form['#attached']['library'][] = 'yamlform/yamlform.element.details.save';
    }

    // Pages: Disable form auto submit on enter for wizard form pages only.
    if ($this
      ->getPages($form, $form_state)) {
      $form['#attributes']['class'][] = 'js-yamlform-disable-autosubmit';
    }

    // Add #after_build callbacks.
    $form['#after_build'][] = '::afterBuild';
    return $form;
  }

  /**
   * Get custom form which is displayed instead of the form's elements.
   *
   * @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.
   *
   * @return array|bool
   *   A custom form or FALSE if the default form containing the form's
   *   elements should be built.
   */
  protected function getCustomForm(array $form, FormStateInterface $form_state) {

    /* @var $yamlform_submission \Drupal\yamlform\YamlFormSubmissionInterface */
    $yamlform_submission = $this
      ->getEntity();
    $yamlform = $this
      ->getYamlForm();

    // Exit if elements are broken, usually occurs when elements YAML is edited
    // directly in the export config file.
    if (!$yamlform_submission
      ->getYamlForm()
      ->getElementsInitialized()) {
      $this->messageManager
        ->display(YamlFormMessageManagerInterface::FORM_EXCEPTION, 'warning');
      return $form;
    }

    // Handle form with managed file upload but saving of submission is disabled.
    if ($yamlform
      ->hasManagedFile() && !empty($this
      ->getYamlFormSetting('results_disabled'))) {
      $this->messageManager
        ->log(YamlFormMessageManagerInterface::FORM_FILE_UPLOAD_EXCEPTION, 'notice');
      $this->messageManager
        ->display(YamlFormMessageManagerInterface::FORM_EXCEPTION, 'warning');
      return $form;
    }

    // Display inline confirmation message with back to link which is rendered
    // via the controller.
    if ($this
      ->getYamlFormSetting('confirmation_type') == 'inline' && $this
      ->getRequest()->query
      ->get('yamlform_id') == $yamlform
      ->id()) {
      $yamlform_controller = new YamlFormController($this->requestHandler, $this->messageManager);
      $form['confirmation'] = $yamlform_controller
        ->confirmation($this
        ->getRequest(), $yamlform);
      return $form;
    }

    // Don't display form if it is closed.
    if ($yamlform_submission
      ->isNew() && $yamlform
      ->isClosed()) {

      // If the current user can update any submission just display the closed
      // message and still allow them to create new submissions.
      if ($yamlform
        ->isTemplate() && $yamlform
        ->access('duplicate')) {
        if (!$this
          ->isModalDialog()) {
          $this->messageManager
            ->display(YamlFormMessageManagerInterface::TEMPLATE_PREVIEW, 'warning');
        }
      }
      elseif ($yamlform
        ->access('submission_update_any')) {
        $this->messageManager
          ->display(YamlFormMessageManagerInterface::ADMIN_ACCESS, 'warning');
      }
      else {
        $form['closed'] = $this->messageManager
          ->build(YamlFormMessageManagerInterface::FORM_CLOSED_MESSAGE);
        return $form;
      }
    }

    // Disable this form if confidential and user is logged in.
    if ($this
      ->isConfidential() && $this
      ->currentUser()
      ->isAuthenticated() && $this->entity
      ->isNew()) {
      $this->messageManager
        ->display(YamlFormMessageManagerInterface::FORM_CONFIDENTIAL_MESSAGE, 'warning');
      return $form;
    }

    // Disable this form if submissions are not being saved to the database or
    // passed to a YamlFormHandler.
    if ($this
      ->getYamlFormSetting('results_disabled') && !$this
      ->getYamlFormSetting('results_disabled_ignore') && !$yamlform
      ->getHandlers(NULL, TRUE, YamlFormHandlerInterface::RESULTS_PROCESSED)
      ->count()) {
      $this->messageManager
        ->log(YamlFormMessageManagerInterface::FORM_SAVE_EXCEPTION, 'error');
      if ($this
        ->currentUser()
        ->hasPermission('administer yamlform')) {

        // Display error to admin but allow them to submit the broken form.
        $this->messageManager
          ->display(YamlFormMessageManagerInterface::FORM_SAVE_EXCEPTION, 'error');
        $this->messageManager
          ->display(YamlFormMessageManagerInterface::ADMIN_ACCESS, 'warning');
      }
      else {

        // Display exception message to users.
        $this->messageManager
          ->display(YamlFormMessageManagerInterface::FORM_EXCEPTION, 'warning');
        return $form;
      }
    }

    // Check total limit.
    if ($this
      ->checkTotalLimit()) {
      $this->messageManager
        ->display(YamlFormMessageManagerInterface::LIMIT_TOTAL_MESSAGE);
      if ($yamlform
        ->access('submission_update_any')) {
        $this->messageManager
          ->display(YamlFormMessageManagerInterface::ADMIN_ACCESS, 'warning');
      }
      else {
        return $form;
      }
    }

    // Check user limit.
    if ($this
      ->checkUserLimit()) {
      $this->messageManager
        ->display(YamlFormMessageManagerInterface::LIMIT_USER_MESSAGE, 'warning');
      if ($yamlform
        ->access('submission_update_any')) {
        $this->messageManager
          ->display(YamlFormMessageManagerInterface::ADMIN_ACCESS, 'warning');
      }
      else {
        return $form;
      }
    }
    return FALSE;
  }

  /**
   * Display draft and previous submission status messages for this form submission.
   *
   * @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 displayMessages(array $form, FormStateInterface $form_state) {

    /* @var $yamlform_submission \Drupal\yamlform\YamlFormSubmissionInterface */
    $yamlform_submission = $this
      ->getEntity();
    $yamlform = $this
      ->getYamlForm();

    // Display test message.
    if ($this
      ->isGet() && $this
      ->isRoute('entity.yamlform.test')) {
      $this->messageManager
        ->display(YamlFormMessageManagerInterface::SUBMISSION_TEST, 'warning');
    }

    // Display loaded or saved draft message.
    if ($yamlform_submission
      ->isDraft()) {
      if ($form_state
        ->get('draft_saved')) {
        $this->messageManager
          ->display(YamlFormMessageManagerInterface::SUBMISSION_DRAFT_SAVED);
        $form_state
          ->set('draft_saved', FALSE);
      }
      elseif ($this
        ->isGet()) {
        $this->messageManager
          ->display(YamlFormMessageManagerInterface::SUBMISSION_DRAFT_LOADED);
      }
    }

    // Display link to previous submissions message when user is adding a new
    // submission.
    if ($this
      ->isGet() && ($this
      ->isRoute('entity.yamlform.canonical') || $this
      ->isYamlFormEntityReferenceFromSourceEntity()) && $yamlform
      ->access('submission_view_own') && ($previous_total = $this->storage
      ->getTotal($yamlform, $this->sourceEntity, $this
      ->currentUser()))) {
      if ($previous_total > 1) {
        $this->messageManager
          ->display(YamlFormMessageManagerInterface::SUBMISSIONS_PREVIOUS);
      }
      elseif ($yamlform_submission
        ->id() != $this->storage
        ->getLastSubmission($yamlform, $this->sourceEntity, $this
        ->currentUser())
        ->id()) {
        $this->messageManager
          ->display(YamlFormMessageManagerInterface::SUBMISSION_PREVIOUS);
      }
    }
  }

  /****************************************************************************/

  // Form actions

  /****************************************************************************/

  /**
   * {@inheritdoc}
   */
  public function afterBuild(array $form, FormStateInterface $form_state) {

    // If form has a custom #action remove Form API fields.
    // @see \Drupal\Core\Form\FormBuilder::prepareForm
    if (strpos($form['#action'], 'form_action_') === FALSE) {

      // Remove 'op' #name from all action buttons.
      foreach (Element::children($form['actions']) as $child_key) {
        unset($form['actions'][$child_key]['#name']);
      }
      unset($form['form_build_id'], $form['form_token'], $form['form_id']);
    }
    return $form;
  }

  /**
   * {@inheritdoc}
   */
  protected function actionsElement(array $form, FormStateInterface $form_state) {

    // Custom forms, which completely override the ContentEntityForm, should
    // not return the actions element (aka submit buttons).
    if (!empty($form['#custom_form'])) {
      return NULL;
    }
    $element = parent::actionsElement($form, $form_state);
    if (!empty($element)) {
      $element['#theme'] = 'yamlform_actions';
    }
    return $element;
  }

  /**
   * {@inheritdoc}
   */
  protected function actions(array $form, FormStateInterface $form_state) {

    /* @var $yamlform_submission \Drupal\yamlform\YamlFormSubmissionInterface */
    $yamlform_submission = $this->entity;
    $yamlform = $this
      ->getYamlForm();
    $element = parent::actions($form, $form_state);

    /* @var \Drupal\yamlform\YamlFormSubmissionInterface $yamlform_submission */
    $preview_mode = $this
      ->getYamlFormSetting('preview');

    // Remove the delete button from the form submission form.
    unset($element['delete']);

    // Mark the submit action as the primary action, when it appears.
    $element['submit']['#button_type'] = 'primary';
    $element['submit']['#attributes'] = $this
      ->getYamlFormSetting('form_submit_attributes');
    $element['submit']['#attributes']['class'][] = 'yamlform-button--submit';

    // Customize the submit button's label for new submissions only.
    if ($yamlform_submission
      ->isNew() || $yamlform_submission
      ->isDraft()) {
      $element['submit']['#value'] = $this
        ->getYamlFormSetting('form_submit_label');
    }

    // Add validate and complete handler to submit.
    $element['submit']['#validate'][] = '::validateForm';
    $element['submit']['#validate'][] = '::autosave';
    $element['submit']['#validate'][] = '::complete';

    // Add confirm(ation) handler to submit button.
    $element['submit']['#submit'][] = '::confirmForm';
    $pages = $this
      ->getPages($form, $form_state);
    $current_page = $this
      ->getCurrentPage($form, $form_state);
    if ($pages) {

      // Get current page element which can contain custom prev(ious) and next button
      // labels.
      $current_page_element = $this
        ->getYamlForm()
        ->getPage($current_page);
      $is_first_page = $current_page == $this
        ->getFirstPage($form, $form_state) ? TRUE : FALSE;
      $is_last_page = in_array($current_page, [
        'preview',
        'complete',
        $this
          ->getLastPage($form, $form_state),
      ]) ? TRUE : FALSE;
      $is_preview_page = $current_page == 'preview';
      $is_next_page_preview = $this
        ->getNextPage($form, $form_state) == 'preview' ? TRUE : FALSE;
      $is_next_page_optional_preview = $is_next_page_preview && $preview_mode != DRUPAL_REQUIRED;

      // Only show that save button if this is the last page of the wizard or
      // on preview page or right before the optional preview.
      $element['submit']['#access'] = $is_last_page || $is_preview_page || $is_next_page_optional_preview;
      if (!$is_first_page) {
        if ($is_preview_page) {
          $previous_attributes = $this
            ->getYamlFormSetting('preview_prev_button_attributes');
          $previous_label = $this
            ->getYamlFormSetting('preview_prev_button_label');
        }
        else {
          $previous_attributes = $this
            ->getYamlFormSetting('wizard_prev_button_attributes');
          $previous_label = isset($current_page_element['#prev_button_label']) ? $current_page_element['#prev_button_label'] : $this
            ->getYamlFormSetting('wizard_prev_button_label');
        }
        $previous_attributes['class'][] = 'js-yamlform-novalidate';
        $previous_attributes['class'][] = 'yamlform-button--previous';
        $element['previous'] = [
          '#type' => 'submit',
          '#value' => $previous_label,
          '#validate' => [
            '::noValidate',
          ],
          '#submit' => [
            '::previous',
          ],
          '#attributes' => $previous_attributes,
        ];
      }
      if (!$is_last_page) {
        if ($is_next_page_preview) {
          $next_attributes = $this
            ->getYamlFormSetting('preview_next_button_attributes');
          $next_label = $this
            ->getYamlFormSetting('preview_next_button_label');
          $next_attributes['class'][] = 'yamlform-button--preview';
        }
        else {
          $next_attributes = $this
            ->getYamlFormSetting('wizard_next_button_attributes');
          $next_label = isset($current_page_element['#next_button_label']) ? $current_page_element['#next_button_label'] : $this
            ->getYamlFormSetting('wizard_next_button_label');
          $next_attributes['class'][] = 'yamlform-button--next';
        }
        $element['next'] = [
          '#type' => 'submit',
          '#value' => $next_label,
          '#validate' => [
            '::validateForm',
          ],
          '#submit' => [
            '::next',
          ],
          '#attributes' => $next_attributes,
        ];
      }
    }

    // Draft.
    if ($this
      ->draftEnabled()) {
      $draft_attributes = $this
        ->getYamlFormSetting('draft_button_attributes');
      $draft_attributes['class'][] = 'yamlform-button--draft';
      $element['draft'] = [
        '#type' => 'submit',
        '#value' => $this
          ->getYamlFormSetting('draft_button_label'),
        '#validate' => [
          '::draft',
        ],
        '#submit' => [
          '::submitForm',
          '::save',
          '::rebuild',
        ],
        '#attributes' => $draft_attributes,
      ];
    }
    return $element;
  }

  /**
   * Form submission handler for the 'next' action.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   */
  public function next(array &$form, FormStateInterface $form_state) {
    if ($form_state
      ->getErrors()) {
      return;
    }
    $form_state
      ->set('current_page', $this
      ->getNextPage($form, $form_state));
    $this
      ->wizardSubmit($form, $form_state);
  }

  /**
   * Form submission handler for the 'previous' action.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   */
  public function previous(array &$form, FormStateInterface $form_state) {
    $form_state
      ->set('current_page', $this
      ->getPreviousPage($form, $form_state));
    $this
      ->wizardSubmit($form, $form_state);
  }

  /**
   * Form submission handler for the wizard submit action.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   */
  protected function wizardSubmit(array &$form, FormStateInterface $form_state) {
    if ($this
      ->draftEnabled() && $this
      ->getYamlFormSetting('draft_auto_save') && !$this->entity
      ->isCompleted()) {
      $form_state
        ->setValue('in_draft', TRUE);
      $this
        ->submitForm($form, $form_state);
      $this
        ->save($form, $form_state);
    }
    else {
      $this
        ->submitForm($form, $form_state);
    }
    $this
      ->rebuild($form, $form_state);
  }

  /**
   * Form submission handler to autosave when there are validation errors.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   */
  public function autosave(array &$form, FormStateInterface $form_state) {
    if ($form_state
      ->hasAnyErrors()) {
      if ($this
        ->draftEnabled() && $this
        ->getYamlFormSetting('draft_auto_save') && !$this->entity
        ->isCompleted()) {
        $form_state
          ->setValue('in_draft', TRUE);
        $this
          ->submitForm($form, $form_state);
        $this
          ->save($form, $form_state);
        $this
          ->rebuild($form, $form_state);
      }
    }
  }

  /**
   * Form submission handler for the 'draft' action.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   */
  public function draft(array &$form, FormStateInterface $form_state) {
    $form_state
      ->clearErrors();
    $form_state
      ->setValue('in_draft', TRUE);
    $form_state
      ->set('draft_saved', TRUE);
    $this->entity
      ->validate();
  }

  /**
   * Form submission handler for the 'complete' action.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   */
  public function complete(array &$form, FormStateInterface $form_state) {
    $form_state
      ->setValue('in_draft', FALSE);
  }

  /**
   * Form submission validation that does nothing but clear validation errors.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   */
  public function noValidate(array &$form, FormStateInterface $form_state) {
    $form_state
      ->clearErrors();
    $this->entity
      ->validate();
  }

  /**
   * Form submission handler for the 'rebuild' action.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   */
  public function rebuild(array &$form, FormStateInterface $form_state) {
    $form_state
      ->setRebuild();
  }

  /**
   * {@inheritdoc}
   */
  public function validateForm(array &$form, FormStateInterface $form_state) {
    parent::validateForm($form, $form_state);

    // Validate form via form handler.
    $this
      ->getYamlForm()
      ->invokeHandlers('validateForm', $form, $form_state, $this->entity);

    // Form validate handlers (via form['#validate']) are not called when
    // #validate handlers are attached to the trigger element
    // (ie submit button), so we need to manually call $form['validate']
    // handlers to support the modules that use form['#validate'] like the
    // validators.module.
    // @see \Drupal\yamlform\YamlFormSubmissionForm::actions
    // @see \Drupal\Core\Form\FormBuilder::doBuildForm
    $trigger_element = $form_state
      ->getTriggeringElement();
    if (isset($trigger_element['#validate'])) {
      $handlers = array_filter($form['#validate'], function ($callback) {

        // Remove ::validateForm to prevent a recursion.
        return is_array($callback) || $callback != '::validateForm';
      });

      // @see \Drupal\Core\Form\FormValidator::executeValidateHandlers
      foreach ($handlers as $callback) {
        call_user_func_array($form_state
          ->prepareCallback($callback), [
          &$form,
          &$form_state,
        ]);
      }
    }
  }

  /**
   * {@inheritdoc}
   */
  public function submitForm(array &$form, FormStateInterface $form_state) {

    /* @var $yamlform_submission \Drupal\yamlform\YamlFormSubmissionInterface */
    $yamlform_submission = $this->entity;
    $yamlform = $yamlform_submission
      ->getYamlForm();

    // Get elements values from form submission.
    $values = array_intersect_key($form_state
      ->getValues(), $yamlform
      ->getElementsFlattenedAndHasValue());

    // Serialize the values as YAML and merge existing data.
    $yamlform_submission
      ->setData($values + $yamlform_submission
      ->getData());
    parent::submitForm($form, $form_state);

    // Submit form via form handler.
    $this
      ->getYamlForm()
      ->invokeHandlers('submitForm', $form, $form_state, $yamlform_submission);
  }

  /**
   * Form confirm(ation) handler.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   */
  public function confirmForm(array &$form, FormStateInterface $form_state) {
    $this
      ->setConfirmation($form_state);

    /** @var \Drupal\yamlform\YamlFormSubmissionInterface $yamlform_submission */
    $yamlform_submission = $this
      ->getEntity();

    // Confirm form via form handler.
    $this
      ->getYamlForm()
      ->invokeHandlers('confirmForm', $form, $form_state, $yamlform_submission);
  }

  /**
   * {@inheritdoc}
   */
  public function save(array $form, FormStateInterface $form_state) {
    $yamlform = $this
      ->getYamlForm();

    /** @var \Drupal\yamlform\YamlFormSubmissionInterface $yamlform_submission */
    $yamlform_submission = $this
      ->getEntity();

    // Set current page.
    if ($current_page = $this
      ->getCurrentPage($form, $form_state)) {
      $yamlform_submission
        ->setCurrentPage($current_page);
    }

    // Make sure the uri and remote addr are set correctly because
    // AJAX requests via 'managed_file' uploads can cause these values to be
    // reset.
    if ($yamlform_submission
      ->isNew()) {
      $yamlform_submission
        ->set('uri', preg_replace('#^' . base_path() . '#', '/', $this
        ->getRequest()
        ->getRequestUri()));
      $yamlform_submission
        ->set('remote_addr', $this
        ->isConfidential() ? '' : $this
        ->getRequest()
        ->getClientIp());
    }

    // Block users from submitting templates that they can't update.
    if ($yamlform
      ->isTemplate() && !$yamlform
      ->access('update')) {
      return;
    }

    // Save and log form submission.
    $yamlform_submission
      ->save();

    // Check limits and invalidate cached and rebuild.
    if ($this
      ->checkTotalLimit() || $this
      ->checkUserLimit()) {
      Cache::invalidateTags([
        'yamlform:' . $this
          ->getYamlForm()
          ->id(),
      ]);
      $form_state
        ->setRebuild();
    }
  }

  /****************************************************************************/

  // Form functions

  /****************************************************************************/

  /**
   * Set the form properties from the elements.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param array $elements
   *   An associative array containing the elements.
   */
  protected function setFormPropertiesFromElements(array &$form, array &$elements) {
    foreach ($elements as $key => $value) {
      if (is_string($key) && $key[0] == '#') {
        if (isset($form[$key]) && is_array($form[$key]) && is_array($value)) {
          $form[$key] = NestedArray::mergeDeep($form[$key], $value);
        }
        else {
          $form[$key] = $value;
        }
        unset($elements[$key]);
      }
    }
  }

  /****************************************************************************/

  // Wizard page functions

  /****************************************************************************/

  /**
   * Get visible wizard pages.
   *
   * Note: The array of pages is stored in the form's state so that it can be
   * altered using hook_form_alter() and #validate callbacks.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   *
   * @return array
   *   Array of visible wizard pages.
   */
  protected function getPages(array &$form, FormStateInterface $form_state) {
    if ($form_state
      ->get('pages') === NULL) {
      $pages = $this
        ->getYamlForm()
        ->getPages();
      foreach ($pages as &$page) {
        $page['#access'] = TRUE;
      }
      $form_state
        ->set('pages', $pages);
    }

    // Get pages and check #access.
    $pages = $form_state
      ->get('pages');
    foreach ($pages as $page_key => $page) {
      if ($page['#access'] === FALSE) {
        unset($pages[$page_key]);
      }
    }
    return $pages;
  }

  /**
   * Get the current page's key.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   *
   * @return string
   *   The current page's key.
   */
  protected function getCurrentPage(array &$form, FormStateInterface $form_state) {
    if ($form_state
      ->get('current_page') === NULL) {
      $pages = $this
        ->getPages($form, $form_state);
      if (empty($pages)) {
        $form_state
          ->set('current_page', '');
      }
      else {
        $current_page = $this->entity
          ->getCurrentPage();
        if ($current_page && isset($pages[$current_page]) && $this
          ->draftEnabled()) {
          $form_state
            ->set('current_page', $current_page);
        }
        else {
          $form_state
            ->set('current_page', YamlFormArrayHelper::getFirstKey($pages));
        }
      }
    }
    return $form_state
      ->get('current_page');
  }

  /**
   * Get first page's key.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   *
   * @return null|string
   *   The first page's key.
   */
  protected function getFirstPage(array &$form, FormStateInterface $form_state) {
    $pages = $this
      ->getPages($form, $form_state);
    return YamlFormArrayHelper::getFirstKey($pages);
  }

  /**
   * Get last page's key.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   *
   * @return null|string
   *   The last page's key.
   */
  protected function getLastPage(array &$form, FormStateInterface $form_state) {
    $pages = $this
      ->getPages($form, $form_state);
    return YamlFormArrayHelper::getLastKey($pages);
  }

  /**
   * Get next page's key.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   *
   * @return null|string
   *   The next page's key. NULL if there is no next page.
   */
  protected function getNextPage(array &$form, FormStateInterface $form_state) {
    $pages = $this
      ->getPages($form, $form_state);
    $current_page = $this
      ->getCurrentPage($form, $form_state);
    return YamlFormArrayHelper::getNextKey($pages, $current_page);
  }

  /**
   * Get previous page's key.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   *
   * @return null|string
   *   The previous page's key. NULL if there is no previous page.
   */
  protected function getPreviousPage(array &$form, FormStateInterface $form_state) {
    $pages = $this
      ->getPages($form, $form_state);
    $current_page = $this
      ->getCurrentPage($form, $form_state);
    return YamlFormArrayHelper::getPreviousKey($pages, $current_page);
  }

  /**
   * Set form wizard current page.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   */
  protected function displayCurrentPage(array &$form, FormStateInterface $form_state) {
    $current_page = $this
      ->getCurrentPage($form, $form_state);
    if ($current_page == 'preview') {

      // Hide elements.
      $form['elements']['#access'] = FALSE;

      // Display preview message.
      $this->messageManager
        ->display(YamlFormMessageManagerInterface::FORM_PREVIEW_MESSAGE, 'warning');

      // Build preview.
      $form['preview'] = [
        '#theme' => 'yamlform_submission_html',
        '#yamlform_submission' => $this->entity,
      ];
    }
    else {

      // Get all pages so that we can also hide skipped pages.
      $pages = $this
        ->getYamlForm()
        ->getPages();
      foreach ($pages as $page_key => $page) {
        if (isset($form['elements'][$page_key])) {
          if ($page_key != $current_page) {
            $form['elements'][$page_key]['#access'] = FALSE;
            $this
              ->hideElements($form['elements'][$page_key]);
          }
          else {
            $form['elements'][$page_key]['#type'] = 'container';
          }
        }
      }
    }
  }

  /****************************************************************************/

  // Form state functions

  /****************************************************************************/

  /**
   * Set form state to redirect to a trusted redirect response.
   *
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   * @param \Drupal\Core\Url $url
   *   A URL object.
   */
  protected function setTrustedRedirectUrl(FormStateInterface $form_state, Url $url) {
    $form_state
      ->setResponse(new TrustedRedirectResponse($url
      ->setAbsolute()
      ->toString()));
  }

  /**
   * Set form state confirmation redirect and message.
   *
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   */
  protected function setConfirmation(FormStateInterface $form_state) {

    /** @var \Drupal\yamlform\YamlFormSubmissionInterface $yamlform_submission */
    $yamlform_submission = $this
      ->getEntity();
    $yamlform = $yamlform_submission
      ->getYamlForm();

    // Get current route name, parameters, and options.
    $route_name = $this
      ->getRouteMatch()
      ->getRouteName();
    $route_parameters = $this
      ->getRouteMatch()
      ->getRawParameters()
      ->all();
    $route_options = [];
    if ($query = $this
      ->getRequest()->query
      ->all()) {
      $route_options['query'] = $query;
    }

    // Default to displaying a confirmation message on this page.
    $state = $yamlform_submission
      ->getState();
    if ($state == YamlFormSubmissionInterface::STATE_UPDATED) {
      $this->messageManager
        ->display(YamlFormMessageManagerInterface::SUBMISSION_UPDATED);
      $form_state
        ->setRedirect($route_name, $route_parameters, $route_options);
      return;
    }

    // Add token route query options.
    if ($state == YamlFormSubmissionInterface::STATE_COMPLETED) {
      $route_options['query']['token'] = $yamlform_submission
        ->getToken();
    }

    // Handle 'page', 'url', and 'inline' confirmation types.
    $confirmation_type = $this
      ->getYamlFormSetting('confirmation_type');
    switch ($confirmation_type) {
      case 'page':
        $redirect_route_name = $this->requestHandler
          ->getRouteName($yamlform, $this->sourceEntity, 'yamlform.confirmation');
        $redirect_route_parameters = $this->requestHandler
          ->getRouteParameters($yamlform, $this->sourceEntity);
        $form_state
          ->setRedirect($redirect_route_name, $redirect_route_parameters, $route_options);
        return;
      case 'url':
      case 'url_message':
        $confirmation_url = trim($this
          ->getYamlFormSetting('confirmation_url', ''));

        // Remove base path from root-relative URL.
        // Only applies for Drupa; sites within a sub directory.
        $confirmation_url = preg_replace('/^' . preg_quote(base_path(), '/') . '/', '/', $confirmation_url);

        // Get system path.

        /** @var \Drupal\Core\Path\AliasManagerInterface $path_alias_manager */
        $path_alias_manager = \Drupal::service('path.alias_manager');
        $confirmation_url = $path_alias_manager
          ->getPathByAlias($confirmation_url);
        if ($redirect_url = \Drupal::pathValidator()
          ->getUrlIfValid($confirmation_url)) {
          if ($confirmation_type == 'url_message') {
            $this->messageManager
              ->display(YamlFormMessageManagerInterface::SUBMISSION_CONFIRMATION);
          }
          $this
            ->setTrustedRedirectUrl($form_state, $redirect_url);
          return;
        }

        // If confirmation URL is invalid display message.
        $this->messageManager
          ->display(YamlFormMessageManagerInterface::SUBMISSION_CONFIRMATION);
        $route_options['query']['yamlform_id'] = $yamlform
          ->id();
        break;
      case 'inline':
        $route_options['query']['yamlform_id'] = $yamlform
          ->id();
        break;
      case 'message':
      default:
        if (!$this->messageManager
          ->display(YamlFormMessageManagerInterface::SUBMISSION_CONFIRMATION)) {
          $this->messageManager
            ->display(YamlFormMessageManagerInterface::SUBMISSION_DEFAULT_CONFIRMATION);
        }
        break;
    }
    $form_state
      ->setRedirect($route_name, $route_parameters, $route_options);
  }

  /****************************************************************************/

  // Elements functions

  /****************************************************************************/

  /**
   * Hide form elements by settings their #access to FALSE.
   *
   * @param array $elements
   *   An render array representing elements.
   */
  protected function hideElements(&$elements) {
    foreach ($elements as $key => &$element) {
      if (Element::property($key) || !is_array($element)) {
        continue;
      }

      // Set #access to FALSE which will suppresses form #required validation.
      $element['#access'] = FALSE;

      // ISSUE: Hidden elements still need to call #element_validate because
      // certain elements, including managed_file, checkboxes, password_confirm,
      // etc..., will also massage the submitted values via #element_validate.
      //
      // SOLUTION: Call #element_validate for all hidden elements but suppresses
      // #element_validate errors.
      //
      // Set hidden element #after_build handler.
      $element['#after_build'][] = [
        get_class($this),
        'hiddenElementAfterBuild',
      ];
      $this
        ->hideElements($element);
    }
  }

  /**
   * Form element #after_build callback: Wrap #element_validate so that we suppress element validation errors.
   */
  public static function hiddenElementAfterBuild(array $element, FormStateInterface $form_state) {
    if (!empty($element['#element_validate'])) {
      $element['#_element_validate'] = $element['#element_validate'];
      $element['#element_validate'] = [
        [
          get_called_class(),
          'hiddenElementValidate',
        ],
      ];
    }
    return $element;
  }

  /**
   * Form element #element_validate callback: Execute #element_validate and suppress errors.
   */
  public static function hiddenElementValidate(array $element, FormStateInterface $form_state) {

    // Create a temp form state that will capture and suppress all element
    // validation errors.
    $temp_form_state = clone $form_state;
    $temp_form_state
      ->setLimitValidationErrors([]);

    // @see \Drupal\Core\Form\FormValidator::doValidateForm
    foreach ($element['#_element_validate'] as $callback) {
      $complete_form =& $form_state
        ->getCompleteForm();
      call_user_func_array($form_state
        ->prepareCallback($callback), [
        &$element,
        &$temp_form_state,
        &$complete_form,
      ]);
    }

    // Get the temp form state's values.
    $form_state
      ->setValues($temp_form_state
      ->getValues());
  }

  /**
   * Prepare form elements.
   *
   * @param array $elements
   *   An render array representing elements.
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   */
  protected function prepareElements(array &$elements, array &$form, FormStateInterface $form_state) {
    foreach ($elements as $key => &$element) {
      if (Element::property($key) || !is_array($element)) {
        continue;
      }

      // Replace default_value tokens
      // Invoke YamlFormElement::prepare.
      $this->elementManager
        ->invokeMethod('prepare', $element, $this->entity);

      // Initialize default values.
      // Invoke YamlFormElement::setDefaultValue.
      $this->elementManager
        ->invokeMethod('setDefaultValue', $element);

      // Allow modules to alter the form element.
      // @see \Drupal\Core\Field\WidgetBase::formSingleElement()
      $hooks = [
        'yamlform_element',
      ];
      if (!empty($element['#type'])) {
        $hooks[] = 'yamlform_element_' . $element['#type'];
      }
      $context = [
        'form' => $form,
      ];
      $this->moduleHandler
        ->alter($hooks, $element, $form_state, $context);

      // Recurse and prepare nested elements.
      $this
        ->prepareElements($element, $form, $form_state);
    }
  }

  /**
   * Prepopulate element data.
   *
   * @param array $data
   *   An array of default.
   */
  protected function prepopulateData(array &$data) {
    if ($this
      ->getYamlFormSetting('form_prepopulate')) {
      $data += $this
        ->getRequest()->query
        ->all();
    }
  }

  /**
   * Populate form elements.
   *
   * @param array $elements
   *   An render array representing elements.
   * @param array $values
   *   An array of values used to populate the elements.
   */
  protected function populateElements(array &$elements, array $values) {
    foreach ($elements as $key => &$element) {
      if (Element::property($key) || !is_array($element)) {
        continue;
      }

      // Populate element if value exists.
      if (isset($element['#type']) && isset($values[$key])) {
        $element['#default_value'] = $values[$key];
      }
      $this
        ->populateElements($element, $values);
    }
  }

  /****************************************************************************/

  // Account related functions

  /****************************************************************************/

  /**
   * Check form submission total limits.
   *
   * @return bool
   *   TRUE if form submission total limit have been met.
   */
  protected function checkTotalLimit() {
    $yamlform = $this
      ->getYamlForm();

    // Check per entity total limit.
    $entity_limit_total = $this
      ->getYamlFormSetting('entity_limit_total');
    if ($entity_limit_total && ($source_entity = $this
      ->getLimitSourceEntity())) {
      if ($this->storage
        ->getTotal($yamlform, $source_entity) >= $entity_limit_total) {
        return TRUE;
      }
    }

    // Check total limit.
    $limit_total = $this
      ->getYamlFormSetting('limit_total');
    if ($limit_total && $this->storage
      ->getTotal($yamlform) >= $limit_total) {
      return TRUE;
    }
    return FALSE;
  }

  /**
   * Check form submission user limit.
   *
   * @return bool
   *   TRUE if form submission user limit have been met.
   */
  protected function checkUserLimit() {
    $account = $this
      ->currentUser();
    $yamlform = $this
      ->getYamlForm();

    // Anonymous users can't have limits.
    if ($account
      ->isAnonymous()) {
      return FALSE;
    }

    // Check per entity user limit.
    $entity_limit_user = $this
      ->getYamlFormSetting('entity_limit_user');
    if ($entity_limit_user && ($source_entity = $this
      ->getLimitSourceEntity())) {
      if ($this->storage
        ->getTotal($yamlform, $source_entity, $account) >= $entity_limit_user) {
        return TRUE;
      }
    }

    // Check user limit.
    $limit_user = $this
      ->getYamlFormSetting('limit_user');
    if ($limit_user && $this->storage
      ->getTotal($yamlform, NULL, $account) >= $limit_user) {
      return TRUE;
    }
    return FALSE;
  }

  /**
   * Determine if drafts are enabled.
   *
   * @return bool
   *   TRUE if drafts are enabled.
   */
  protected function draftEnabled() {
    $account = $this
      ->currentUser();
    return $account
      ->isAuthenticated() && $this
      ->getYamlFormSetting('draft') && !$this
      ->getYamlFormSetting('results_disabled') ? TRUE : FALSE;
  }

  /**
   * Returns the form confidential indicator.
   *
   * @return bool
   *   TRUE if the form is confidential .
   */
  protected function isConfidential() {
    return $this
      ->getYamlFormSetting('form_confidential', FALSE);
  }

  /**
   * Is client side validation disabled (using the form novalidate attribute).
   *
   * @return bool
   *   TRUE if the client side validation disabled.
   */
  protected function isFormNoValidate() {
    return $this
      ->getYamlFormSetting('form_novalidate', FALSE);
  }

  /**
   * Is the form being initially loaded via GET method.
   *
   * @return bool
   *   TRUE if the form is being initially loaded via GET method.
   */
  protected function isGet() {
    return $this
      ->getRequest()
      ->getMethod() == 'GET' ? TRUE : FALSE;
  }

  /**
   * Determine if the current request is a specific route (name).
   *
   * @param string $route_name
   *   A route name.
   *
   * @return bool
   *   TRUE if the current request is a specific route (name).
   */
  protected function isRoute($route_name) {
    return $route_name == $this
      ->getRouteMatch()
      ->getRouteName() ? TRUE : FALSE;
  }

  /**
   * Is the current form an entity reference from the source entity.
   *
   * @return bool
   *   TRUE is the current form an entity reference from the source entity.
   */
  protected function isYamlFormEntityReferenceFromSourceEntity() {
    return $this->sourceEntity && method_exists($this->sourceEntity, 'hasField') && $this->sourceEntity
      ->hasField('yamlform') && $this->sourceEntity->yamlform->target_id == $this
      ->getYamlForm()
      ->id();
  }

  /****************************************************************************/

  // Helper functions

  /****************************************************************************/

  /**
   * Get the form submission's form.
   *
   * @return \Drupal\yamlform\YamlFormInterface
   *   A form.
   */
  protected function getYamlForm() {

    /** @var \Drupal\yamlform\YamlFormSubmissionInterface $yamlform_submission */
    $yamlform_submission = $this
      ->getEntity();
    return $yamlform_submission
      ->getYamlForm();
  }

  /**
   * Get the form submission's source entity.
   *
   * @return \Drupal\Core\Entity\EntityInterface
   *   The form submission's source entity.
   */
  protected function getSourceEntity() {
    return $this->sourceEntity;
  }

  /**
   * Get source entity for use with entity limit total and user submissions.
   *
   * @return \Drupal\Core\Entity\EntityInterface|null
   *   The form submission's source entity.
   */
  protected function getLimitSourceEntity() {

    /** @var \Drupal\yamlform\YamlFormSubmissionInterface $yamlform_submission */
    $yamlform_submission = $this
      ->getEntity();
    $source_entity = $yamlform_submission
      ->getSourceEntity();
    if ($source_entity && $source_entity
      ->getEntityTypeId() != 'yamlform') {
      return $source_entity;
    }
    return NULL;
  }

  /**
   * Get a form submission's form setting.
   *
   * @param string $name
   *   Setting name.
   * @param null|mixed $default_value
   *   Default value.
   *
   * @return mixed
   *   A form setting.
   */
  protected function getYamlFormSetting($name, $default_value = NULL) {

    // Get form settings with default values.
    if (empty($this->settings)) {
      $this->settings = $this
        ->getYamlForm()
        ->getSettings();
      $default_settings = $this
        ->config('yamlform.settings')
        ->get('settings');
      foreach ($default_settings as $key => $value) {
        $key = str_replace('default_', '', $key);
        if (empty($this->settings[$key])) {
          $this->settings[$key] = $value;
        }
      }
    }
    if (isset($this->settings[$name])) {
      return $this->tokenManager
        ->replace($this->settings[$name], $this
        ->getEntity());
    }
    else {
      return $default_value;
    }
  }

}

Classes

Name	Description
YamlFormSubmissionForm	Provides a form to collect and edit submissions.