TimeZoneCacheContext.php

<?php

namespace Drupal\Core\Cache\Context;

use Drupal\Core\Cache\CacheableMetadata;

/**
 * Defines the TimeZoneCacheContext service, for "per time zone" caching.
 *
 * Cache context ID: 'timezone'.
 *
 * @see \Drupal\Core\Session\AccountProxy::setAccount()
 */
class TimeZoneCacheContext implements CacheContextInterface {
    
    /**
     * {@inheritdoc}
     */
    public static function getLabel() {
        return t("Time zone");
    }
    
    /**
     * {@inheritdoc}
     */
    public function getContext() {
        // date_default_timezone_set() is called in AccountProxy::setAccount(), so
        // we can safely retrieve the timezone.
        return date_default_timezone_get();
    }
    
    /**
     * {@inheritdoc}
     */
    public function getCacheableMetadata() {
        return new CacheableMetadata();
    }

}