Psr15 Dispatcher

The Psr15 Dispatcher component allows you to dispatch PSR-15 middlewares.

Installation

To install the latest stable version of this component, open a console and execute the following command:

$ composer require ajgarlag/psr15-dispatcher

Usage

At first, you must have an app that implements RequestHandlerInterface or is wrapped in a RequestHandlerInterface implementation, that you would like to dispatch decorated with several PSR-15 middlewares.

/* @var $requestHandler RequestHandlerInterface */
$requestHandler = new YourApp();

Now, you can choose between a Pipe or a Stack to dispatch your app.

Pipe dispatch

With this option, you create a Pipe, connect the desired middlewares and finally process the server request through the pipe, passing your app as request handler:

use Ajgarlag\Psr15\Dispatcher\Pipe;

$pipe = Pipe::create()
    ->withConnectedMiddleware(new FirstMiddleware())
    ->withConnectedMiddleware(new MiddleMiddleware())
    ->withConnectedMiddleware(new LastMiddleware())
;

$response = $pipe->process($request, $requestHandler);

The Pipe class implements itself the PSR-15 MiddlewareInterface, so it can be connected to another Pipe.

Pipe initialization

You can pass a FIFO array of middlewares to initialize the Pipe:

$pipe = Pipe::create([
    new FirstMiddleware(),
    new MiddleMiddleware(),
    new LastMiddleware(),
]);

Stack dispatch

With this option, you wrap your app request handler into an Stack instance, push the desired middlewares and finally process the server request through the stack. Beware that to achieve the same behavior that in the previous Pipe you must push middlewares in reverse order:

use Ajgarlag\Psr15\Dispatcher\Stack;

$stack = Stack::create($requestHandler)
    ->withPushedMiddleware(new LastMiddleware())
    ->withPushedMiddleware(new MiddleMiddleware())
    ->withPushedMiddleware(new FirstMiddleware())
;

$response = $stack->handle($request);

The Stack class implements itself the PSR-15 RequestHandlerInterface, so it can be wrapped by another Stack.

Stack initialization

You can pass a LIFO array of middlewares to initialize the Stack:

$stack = Stack::create($requestHandler, [
    new LastMiddleware(),
    new MiddleMiddleware(),
    new FirstMiddleware(),
]);

Pipe pushed onto the stack

My preferred option is to build a Pipe with middlewares connected in natural order, and then, push it onto the stack, but this is a matter of taste:

$stack = Stack::create($requestHandler);
$pipe = Pipe::create()
    ->withConnectedMiddleware(new FirstMiddleware())
    ->withConnectedMiddleware(new MiddleMiddleware())
    ->withConnectedMiddleware(new LastMiddleware())
;

$application = $stack->withPushedMiddleware($pipe);

License

This component is under the MIT license. See the complete license in the LICENSE file.

Reporting an issue or a feature request

Issues and feature requests are tracked in the Github issue tracker.

Author Information

Developed with ♥ by Antonio J. García Lagar.

If you find this component useful, please add a ★ in the GitHub repository page and/or the Packagist package page.