Drupal 8 EntityController

NodeEntityController.php

<?php

namespace Drupal\my_module\Controller;

use Drupal\Core\Controller\ControllerBase;
use Drupal\node\Entity\Node;
use Symfony\Component\DependencyInjection\ContainerInterface;
use Drupal\Core\Entity\EntityTypeManager;
use Drupal\Core\Entity\Query\QueryFactory;
use Drupal\Core\Render\Renderer;

/**
 * Class NodeEntityController.
 *
 * @package Drupal\my_module\Controller
 */
class NodeEntityController extends ControllerBase {

  /**
   * Drupal\Core\Entity\EntityTypeManager definition.
   *
   * @var \Drupal\Core\Entity\EntityTypeManager
   */
  protected $entityTypeManager;
  
  /**
   * Drupal\Core\Entity\Query\QueryFactory definition.
   *
   * @var Drupal\Core\Entity\Query\QueryFactory
   */
  protected $entityQuery;

  /**
   * Drupal\Core\Render\Renderer definition.
   *
   * @var \Drupal\Core\Render\Renderer
   */
  protected $renderer;

  /**
   * {@inheritdoc}
   */
  public function __construct(EntityTypeManager $entity_type_manager,
                              QueryFactory $entity_query,
                              Renderer $renderer) {
    $this->entityTypeManager = $entity_type_manager;
    $this->entityQuery = $entity_query;
    $this->renderer = $renderer;
  }

  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container) {
    return new static(
      $container->get('entity_type.manager'),
      $container->get('entity.query'),
      $container->get('renderer')
    );
  }

  /**
   * Returns node ids for a content type.
   *
   * @param $type
   * @return array|int
   */
  private function getNodeIds($content_type) {
    $query = $this->entityQuery->get('node')
      ->condition('type', $content_type);
    $ids = $query->execute();
    return $ids;
  }

  /**
   * Returns the markup for a single node
   */
  private function getNodeMarkup($node_id, $view_mode = 'full') {
    $node = $this->entityTypeManager->getStorage('node')->load($node_id);
    $currentLanguageId = $this->languageManager->getCurrentLanguage()->getId();
    if($node instanceof Node && $node->hasTranslation($currentLanguageId)) {
      $nodeTranslation = $node->getTranslation($currentLanguageId);
      $node = $nodeTranslation;
    }
    $viewBuilder = $this->entityTypeManager->getViewBuilder($node->getEntityTypeId());
    $nodeView = $viewBuilder->view($node, $view_mode, $this->languageManager->getCurrentLanguage());

    $build = [
      '#markup' => $this->renderer->render($nodeView),
    ];
    return $build;
  }
  
  
  private function getNodeList($content_type) {
    $ids = $this->getNodeIds($content_type);
    $nodes = [];
    // for example only, we should make use of loadMultiple instead
    foreach($ids as $nodeId) {
      $nodes[] = $this->getNodeMarkup($nodeId);
    }
    return $nodes;
  }

  /**
   * Default page.
   *
   * @return string
   *   Return Node list.
   */
  public function main() {
    $build = [
      '#theme' => 'item_list',
      '#items' => $this->getNodeList('my_content_type'),
      '#type' => 'ul',
    ];

    return $build;
  }

}