README

Yii Middleware Dispatcher

The package is a PSR-15 middleware dispatcher. Given a set of middleware and a request instance, dispatcher executes it produces a response instance.

Requirements

PHP 8.0 or higher.

Installation

The package could be installed with composer:

composer require yiisoft/middleware-dispatcher

General usage

To use a dispatcher, you need to create it first:

use Yiisoft\Middleware\Dispatcher\MiddlewareDispatcher;
use Yiisoft\Middleware\Dispatcher\MiddlewareFactory;

$dispatcher = new MiddlewareDispatcher(
    new MiddlewareFactory($diContainer),
    $eventDispatcher
);

In the above $diContainer is an instance of PSR-11 \Psr\Container\ContainerInterface and $eventDispatcher is an instance of PSR-14 Psr\EventDispatcher\EventDispatcherInterface.

After dispatcher instance obtained, it should be fed with some middleware:

$dispatcher = $dispatcher->withMiddlewares([
    TeapotAccessChecker::class,
    static function (): ResponseInterface {
        return new Response(418);
    },
]);

In the above we have used a callback. Overall the following options are available:

A controller handler action in format [TestController::class, 'index']. TestController instance will be created and index() method will be executed.
A name of PSR-15 middleware class. The middleware instance will be obtained from container.
A name of PSR-15 request handler class. The request handler instance will be obtained from container and executed.
A name or instance of invokable class. If the name of invokable class is provided, the instance will be obtained from container and executed.

A function returning a middleware such as

static function (): MiddlewareInterface {
    return new TestMiddleware();
}

The middleware returned will be executed.

A callback function(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface.

An array definition (see syntax) of middleware:

[
    'class' => MyMiddleware::class,
    '__construct()' => [
        'someVar' => 42,
    ],
]

For handler action and callable typed parameters are automatically injected using dependency injection container. Current request and handler could be obtained by type-hinting for ServerRequestInterface and RequestHandlerInterface.

After middleware set is defined, you can do the dispatching:

$request = new ServerRequest('GET', '/teapot');
$response = $dispatcher->dispatch($request, $this->getRequestHandler());

Given a request dispatcher executes middleware in the set and produces response. First specified middleware will be executed first. For each middleware \Yiisoft\Middleware\Dispatcher\Event\BeforeMiddleware and \Yiisoft\Middleware\Dispatcher\Event\AfterMiddleware events are triggered.

Creating your own implementation of parameters resolver

Parameters resolver could be customized by providing your own ParametersResolverInterface implementation:

use \Psr\Http\Message\ServerRequestInterface;
use \Yiisoft\Middleware\Dispatcher\ParametersResolverInterface;

class CoolParametersResolver implements ParametersResolverInterface
{
    public function resolve(array $parameters, ServerRequestInterface $request): MiddlewareInterface
    {
        $resolvedParameters = [];
        foreach ($parameters as $name => $parameter) {
            if ($request->getAttribute($name) !== null) {
                $resolvedParameters[$name] = $request->getAttribute($name)
            }
        }
        
        return $resolvedParameters;
    }
}

Then it could be used like the following:

use Yiisoft\Middleware\Dispatcher\MiddlewareDispatcher;
use Yiisoft\Middleware\Dispatcher\MiddlewareFactory;

$dispatcher = new MiddlewareDispatcher(
    new MiddlewareFactory($diContainer, new CoolParametersResolver()),
    $eventDispatcher
);

To combine several parameters' resolvers use CompositeParametersResolver:

use Yiisoft\Middleware\Dispatcher\CompositeParametersResolver;
use Yiisoft\Middleware\Dispatcher\MiddlewareDispatcher;
use Yiisoft\Middleware\Dispatcher\MiddlewareFactory;

$dispatcher = new MiddlewareDispatcher(
    new MiddlewareFactory(
        $diContainer, new CompositeParametersResolver(
            new CoolParametersResolver(),
            new YetAnotherParametersResolver(),
        )
    ),
    $eventDispatcher
);

Testing

Unit testing

The package is tested with PHPUnit. To run tests:

./vendor/bin/phpunit

Mutation testing

The package tests are checked with Infection mutation framework with Infection Static Analysis Plugin. To run it:

./vendor/bin/roave-infection-static-analysis-plugin

Static analysis

The code is statically analyzed with Psalm. To run static analysis:

./vendor/bin/psalm

License

The Yii Middleware Dispatcher is free software. It is released under the terms of the BSD License. Please see LICENSE for more information.

Maintained by Yii Software.

yiisoft / middleware-dispatcher

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