component_library-1.0.x-dev/src/VariationTemplateLoader.php

<?php

declare(strict_types=1);

namespace Drupal\component_library;

use Drupal\Core\Cache\CacheBackendInterface;
use Drupal\Core\Entity\EntityTypeManagerInterface;
use Twig\Error\LoaderError;
use Twig\Loader\LoaderInterface;
use Twig\Source;

/**
 * Loads templates from the component variation storage.
 */
final class VariationTemplateLoader implements LoaderInterface {

  /**
   * The entity_type.manager service.
   */
  private EntityTypeManagerInterface $entityTypeManager;

  /**
   * The instantiated Cache backend.
   */
  private CacheBackendInterface $configCache;

  /**
   * Constructs a new template loader instance.
   */
  public function __construct(EntityTypeManagerInterface $entity_type_manager, CacheBackendInterface $config_cache) {
    $this->entityTypeManager = $entity_type_manager;
    $this->configCache = $config_cache;
  }

  /**
   * {@inheritdoc}
   */
  public function exists($name): bool {
    if (\str_starts_with($name, '@component_variation/')) {
      $variation_id = \explode('/', $name, 2)[1];
      $variation = $this->entityTypeManager
        ->getStorage('component_library_variant')
        ->load($variation_id);
      return (bool) $variation;
    }
    return FALSE;
  }

  /**
   * {@inheritdoc}
   */
  public function getSourceContext($name): Source {
    $variation_id = \explode('/', $name)[1];

    $variation = $this->entityTypeManager->getStorage('component_library_variant')->load($variation_id);
    if (!$variation) {
      throw new LoaderError(\sprintf('Could not load variation "%s".', $variation_id));
    }
    return new Source($variation->get('template'), $name);
  }

  /**
   * {@inheritdoc}
   */
  public function getCacheKey($name): string {
    return $name;
  }

  /**
   * {@inheritdoc}
   */
  public function isFresh($name, $time): bool {
    // Variation entity does not have "changed" property. So we check freshness
    // using config cache.
    $variation_id = \explode('/', $name, 2)[1];
    $cache = $this->configCache->get('component_library.variant.' . $variation_id);
    return $cache && ($time > $cache->created);
  }

}