Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\Core\PageCache;
Chris@0: 
Chris@0: use Symfony\Component\HttpFoundation\Request;
Chris@0: 
Chris@0: /**
Chris@0:  * Implements a compound request policy.
Chris@0:  *
Chris@0:  * When evaluating the compound policy, all of the contained rules are applied
Chris@0:  * to the request. The overall result is computed according to the following
Chris@0:  * rules:
Chris@0:  *
Chris@0:  * <ol>
Chris@0:  *   <li>Returns static::DENY if any of the rules evaluated to static::DENY</li>
Chris@0:  *   <li>Returns static::ALLOW if at least one of the rules evaluated to
Chris@0:  *       static::ALLOW and none to static::DENY</li>
Chris@0:  *   <li>Otherwise returns NULL</li>
Chris@0:  * </ol>
Chris@0:  */
Chris@0: class ChainRequestPolicy implements ChainRequestPolicyInterface {
Chris@0: 
Chris@0:   /**
Chris@0:    * A list of policy rules to apply when this policy is evaluated.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\PageCache\RequestPolicyInterface[]
Chris@0:    */
Chris@0:   protected $rules = [];
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function check(Request $request) {
Chris@0:     $final_result = NULL;
Chris@0: 
Chris@0:     foreach ($this->rules as $rule) {
Chris@0:       $result = $rule->check($request);
Chris@0:       if ($result === static::DENY) {
Chris@0:         return $result;
Chris@0:       }
Chris@0:       elseif ($result === static::ALLOW) {
Chris@0:         $final_result = $result;
Chris@0:       }
Chris@0:       elseif (isset($result)) {
Chris@0:         throw new \UnexpectedValueException('Return value of RequestPolicyInterface::check() must be one of RequestPolicyInterface::ALLOW, RequestPolicyInterface::DENY or NULL');
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     return $final_result;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function addPolicy(RequestPolicyInterface $policy) {
Chris@0:     $this->rules[] = $policy;
Chris@0:     return $this;
Chris@0:   }
Chris@0: 
Chris@0: }