function AcceptHeaderMatcher::filter

Overrides FilterInterface::filter

File

core/modules/system/tests/modules/accept_header_routing_test/src/Routing/AcceptHeaderMatcher.php, line 18

Class

AcceptHeaderMatcher

Filters routes based on the media type specified in the HTTP Accept headers.

Namespace

Code

public function filter(RouteCollection $collection, Request $request) {
    // Generates a list of Symfony formats matching the acceptable MIME types.
    // @todo replace by proper content negotiation library.
    $acceptable_mime_types = $request->getAcceptableContentTypes();
    $acceptable_formats = array_filter(array_map([
        $request,
        'getFormat',
    ], $acceptable_mime_types));
    $primary_format = $request->getRequestFormat();
    foreach ($collection as $name => $route) {
        // _format could be a |-delimited list of supported formats.
        $supported_formats = array_filter(explode('|', $route->getRequirement('_format') ?? ''));
        if (empty($supported_formats)) {
            // No format restriction on the route, so it always matches. Move it to
            // the end of the collection by re-adding it.
            $collection->add($name, $route);
        }
        elseif (in_array($primary_format, $supported_formats)) {
            // Perfect match, which will get a higher priority by leaving the route
            // on top of the list.
        }
        elseif (in_array('*/*', $acceptable_mime_types) || array_intersect($acceptable_formats, $supported_formats)) {
            // Move it to the end of the list.
            $collection->add($name, $route);
        }
        else {
            // Remove the route if it does not match at all.
            $collection->remove($name);
        }
    }
    if (count($collection)) {
        return $collection;
    }
    // We do not throw a
    // \Symfony\Component\Routing\Exception\ResourceNotFoundException here
    // because we don't want to return a 404 status code, but rather a 406.
    throw new NotAcceptableHttpException('No route found for the specified formats ' . implode(' ', $acceptable_mime_types));
}