function Response::isNotModified

Determines if the Response validators (ETag, Last-Modified) match a conditional value specified in the Request.

If the Response is not modified, it sets the status code to 304 and removes the actual content by calling the setNotModified() method.

@final

File

vendor/symfony/http-foundation/Response.php, line 1111

Class

Response

Response represents an HTTP response.

Namespace

Symfony\Component\HttpFoundation

Code

public function isNotModified(Request $request) : bool {
    if (!$request->isMethodCacheable()) {
        return false;
    }
    $notModified = false;
    $lastModified = $this->headers
        ->get('Last-Modified');
    $modifiedSince = $request->headers
        ->get('If-Modified-Since');
    if (($ifNoneMatchEtags = $request->getETags()) && null !== ($etag = $this->getEtag())) {
        if (0 == strncmp($etag, 'W/', 2)) {
            $etag = substr($etag, 2);
        }
        // Use weak comparison as per https://tools.ietf.org/html/rfc7232#section-3.2.
        foreach ($ifNoneMatchEtags as $ifNoneMatchEtag) {
            if (0 == strncmp($ifNoneMatchEtag, 'W/', 2)) {
                $ifNoneMatchEtag = substr($ifNoneMatchEtag, 2);
            }
            if ($ifNoneMatchEtag === $etag || '*' === $ifNoneMatchEtag) {
                $notModified = true;
                break;
            }
        }
    }
    elseif ($modifiedSince && $lastModified) {
        $notModified = strtotime($modifiedSince) >= strtotime($lastModified);
    }
    if ($notModified) {
        $this->setNotModified();
    }
    return $notModified;
}