A webform embed element for Acquia Site Studio, including dependency injection

WebformElement.php

<?php

namespace Drupal\webform_element\Plugin\CustomElement;

use Drupal\cohesion_elements\CustomElementPluginBase;
use Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException;
use Drupal\Component\Plugin\Exception\PluginNotFoundException;
use Drupal\Core\Entity\EntityTypeManagerInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * Webform element plugin for DX8.
 *
 * @package Drupal\cohesion\Plugin\CustomElement
 *
 * @CustomElement(
 *   id = "webform_element",
 *   label = @Translation("Webform element")
 * )
 */
class WebformElement extends CustomElementPluginBase {

  /**
   * An instance of the entity type manager.
   *
   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
   */
  protected EntityTypeManagerInterface $entityTypeManager;

  /**
   * {@inheritdoc}
   */
  public function __construct($configuration, $plugin_id, $plugin_definition, EntityTypeManagerInterface $entityTypeManager) {
    $this->entityTypeManager = $entityTypeManager;
    parent::__construct($configuration, $plugin_id, $plugin_definition);
  }

  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
    return new static(
      $configuration,
      $plugin_id,
      $plugin_definition,
      $container->get('entity_type.manager')
    );
  }

  /**
   * {@inheritdoc}
   */
  public function getFields() {
    return [
      'webform' => [
        'title' => 'Webform machine name',
        'type' => 'textfield',
        'required' => TRUE,
        'validationMessage' => 'This field is required.',
      ],
    ];
  }

  /**
   * {@inheritdoc}
   */
  public function render($element_settings, $element_markup, $element_class, $element_context = []) {
    try {
      $webform = $this->entityTypeManager
        ->getStorage('webform')
        ->load($element_settings['webform']);
    }
    catch (InvalidPluginDefinitionException | PluginNotFoundException) {
    }

    $view_builder = $this->entityTypeManager
      ->getViewBuilder('webform');
    $build = $view_builder->view($webform);

    // Render the element.
    return [
      '#theme' => 'webform_element',
      '#template' => 'webform-element-template',
      '#elementSettings' => $element_settings,
      '#elementMarkup' => $element_markup,
      '#elementContext' => $element_context,
      '#elementClass' => $element_class,
      '#webform' => $build,
    ];
  }

}