Frame implements a simple PSR-15 compatible middleware dispatcher.
Frame is composer managed, so the easiest way to install it is to require xoops/frame.
Rack is a middleware dispatcher. Instances of Psr\Http\Server\MiddlewareInterface can be added
to the rack. After the desired middlewares have been added, it is dispatched by passing a
Psr\Http\Message\ServerRequestInterface object to the rack run() method.
$rack = new \Xoops\Frame\Rack();
$rack->add($someMiddleware);
$rack->add($anotherMiddleware);
$response = $rack->run($request);Rack will invoke each middleware in the order it was added. Rack will pass itself to
each middleware as the Psr\Http\Server\RequestHandlerInterface $handler parameter,
and when called as such will dispatch the next middleware in its queue.
The racked middleware is expected to ultimately return a Psr\Http\Message\ResponseInterface
object, and as per PSR-15, it will be returned from the run() invocation.
As an alternative to the run() method, you can depend on the __invoke() method to allow calling the Rack instance as a function.
$response = $rack($request);A Rack instance is also a Psr\Http\Server\MiddlewareInterface object. This
allows a Rack instance to be used as middleware, allowing a racks to be stacked.
This namespace defines the following exceptions which can be thrown by Rack:
This results from either trying to add a Rack instance to itself as middleware, or from
forcinging something other than a valid Psr\Http\Server\MiddlewareInterface object to
the middleware queue.
This exception results from attempting to advance past the end of the middleware queue. This condition indicates that no response message has been returned and there is no handler on the middleware queue to delegate response creation to.
The Panel namespace contains several small rack panels that might be useful middleware
in a duct tape sort of role.
Blank is just a placeholder. It does nothing other than delegate and return the response.
$rack->addToQueue(new Blank);
ClosureToMiddleware lets you build middleware from a PHP Closure or anonymous function.
$callable = function (RequestInterface $request, RequestHandlerInterface $handler) {
$response = $handler->handle($request);
$modifiedResponse = $response->withHeader('X-Powered-By', 'black coffee');
return $modifiedResponse;
};
$middleware = new ClosureToMiddleware($callable);
$rack->add($middleware);FixedResponse returns the Psr\Http\Message\ResponseInterface passed to it at instantiation.
$response = $myResponseFactory->createResponse(200);
$rack->add(new FixedResponse($response));