og-8.x-1.x-dev/src/Cache/Context/OgMembershipStateCacheContext.php

<?php

declare(strict_types=1);

namespace Drupal\og\Cache\Context;

use Drupal\Core\Cache\CacheableMetadata;
use Drupal\Core\Cache\Context\CacheContextInterface;
use Drupal\Core\Session\AccountInterface;
use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\og\MembershipManagerInterface;
use Drupal\og\OgContextInterface;
use Drupal\og\OgMembershipInterface;

/**
 * Defines a cache context service, for "membership state" caching.
 *
 * Cache context ID: 'og_membership_state'
 */
class OgMembershipStateCacheContext implements CacheContextInterface {

  /**
   * The string to return when no context is found.
   */
  const NO_CONTEXT = 'none';

  public function __construct(
    protected readonly AccountInterface $user,
    protected readonly OgContextInterface $ogContext,
    protected readonly MembershipManagerInterface $membershipManager,
  ) {}

  /**
   * {@inheritdoc}
   */
  public static function getLabel() {
    return new TranslatableMarkup('OG membership state');
  }

  /**
   * {@inheritdoc}
   */
  public function getContext() {
    // Do not provide a cache context if there is no group in the current
    // context.
    $group = $this->ogContext->getGroup();
    if (empty($group)) {
      return self::NO_CONTEXT;
    }

    /** @var \Drupal\og\OgMembershipInterface $membership */
    $membership = $this->membershipManager->getMembership($group, $this->user->id(), OgMembershipInterface::ALL_STATES);
    return $membership ? $membership->getState() : self::NO_CONTEXT;
  }

  /**
   * {@inheritdoc}
   */
  public function getCacheableMetadata() {
    return new CacheableMetadata();
  }

}