/** * Handle a 304 response and ensure that it is still valid * * @param RequestInterface $request Request that was sent * @param Response $validateResponse Response received * @param Response $response Original cached response * * @return bool Returns true if valid, false if invalid */ protected function handle304Response(RequestInterface $request, Response $validateResponse, Response $response) { static $replaceHeaders = array('Date', 'Expires', 'Cache-Control', 'ETag', 'Last-Modified'); // Make sure that this response has the same ETag if ($validateResponse->getEtag() != $response->getEtag()) { return false; } // Replace cached headers with any of these headers from the // origin server that might be more up to date $modified = false; foreach ($replaceHeaders as $name) { if ($validateResponse->hasHeader($name)) { $modified = true; $response->setHeader($name, $validateResponse->getHeader($name)); } } // Store the updated response in cache if ($modified && $this->canCache->canCacheResponse($response)) { $this->storage->cache($request, $response); } return true; }