Support checkboxes in GraphQL 4.

Closes #3424602

d10/src/Plugin/GraphQL/DataProducer/WebformItems.php

-<?php
-
-namespace Drupal\graphql_webform\Plugin\GraphQL\DataProducer;
-
-use Drupal\Core\Render\Element;
-use Drupal\graphql\GraphQL\Execution\FieldContext;
-use Drupal\graphql\Plugin\GraphQL\DataProducer\DataProducerPluginBase;
-use Drupal\webform\WebformInterface;
-
-/**
- * Return the webform items.
- *
- * @DataProducer(
- *   id = "webform_items",
- *   name = @Translation("Webform Items"),
- *   description = @Translation("Returns the webforms items (elements)."),
- *   produces = @ContextDefinition("any",
- *     label = @Translation("Webform Items"),
- *     required = FALSE
- *   ),
- *   consumes = {
- *     "webform" = @ContextDefinition("entity:webform",
- *       label = @Translation("Webform")
- *     ),
- *     "form" = @ContextDefinition("any",
- *       label = @Translation("Webform Submission Form")
- *     )
- *   }
- * )
- */
-class WebformItems extends DataProducerPluginBase {
-
-  /**
-   * Resolver.
-   */
-  public function resolve(WebformInterface $webform, array $form, FieldContext $field) {
-    $elements = empty($form['elements']) ? $form : $form['elements'];
-    $childKeys = Element::children($elements, TRUE);
-    $data = $webform->getElementsDecodedAndFlattened('view');
-    $items = [];
-    foreach ($childKeys as $key) {
-      $element = $elements[$key] ?? NULL;
-      if ($element) {
-        $element['#graphql_element_decoded'] = $data[$key] ?? NULL;
-        $items[] = $element;
-      }
-    }
-    return $items;
-  }
-
-}