Host name routing in Zend Expressive

Question

Zend Expressive has an adapters for Aura.Router, FastRoute and zend-mvc Router and the route can match the method and path easily:

<?php
$app->get('/foo', $middleware);

With zend-mvc Router component it is possible to match the hostname:

<?php
use Zend\Mvc\Router\Http\Hostname;

$route = Hostname::factory([
    'route' => ':subdomain.example.com/foo',
    'constraints' => [
        'subdomain' => 'api',
    ],
]);

$router->addRoute('foo', $route);

This is also possible with Symfony Routing Component :

<?php
use Symfony\Component\Routing\RouteCollection;
use Symfony\Component\Routing\Route;

$route = new Route(
    '/foo', // path
    array('_controller' => 'SomeController'), // default values
    array('subdomain' => 'api'), // requirements
    array(), // options
    '{subdomain}.example.com', // host
    array(), // schemes
    array() // methods
);

$routes = new RouteCollection();
$routes->add('foo', $route);

So, I would like to be able to do something similar with Expressive, and to dispatch the request to a different middleware depending on the subdomain:

// dispatch the requiest to ApiMiddleware
$app->get(':subdomain.example.com/foo', $ApiMiddleware, ['subdomain' => 'api']);

// dispatch the requiest to WebMiddleware
$app->get(':subdomain.example.com/foo', $WebMiddleware, ['subdomain' => 'www']);

Thanks in advance!

Answer 1

Why did you not create a new middleware for extracting the request and choose which middleware should be called in the pipeline next?

You could do something like that:

Application\\Middleware\\DeciderMiddleware

<?php

namespace Application\Middleware;

use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\ServerRequestInterface;

class DeciderMiddleware
{
    protected $apiMiddleware;
    protected $webMiddleware;

    public function __construct(
        callable $apiMiddleware,
        callable $webMiddleware
    ) {
        $this->apiMiddleware = $apiMiddleware;
        $this->webMiddleware = $webMiddleware;
    }

    public function __invoke(
        ServerRequestInterface $request,
        ResponseInterface $response,
        callable $next = null
    ) {
        if (strpos($request->getUri()->getHost(), 'api.') === 0) {
            return ($this->apiMiddleware)($request, $response);
        }

        if (strpos($request->getUri()->getHost(), 'www.') === 0) {
            return ($this->webMiddleware)($request, $response);
        }

        return $next($request, $response);
    }
}

config/autoload/middleware-pipeline.global.php

<?php

return [
    'dependencies' => [
        'factories' => [
            Application\Middleware\DeciderMiddleware::class => Application\Middleware\DeciderMiddlewareFactory::class
        ],
    ],
    'middleware_pipeline' => [
        'always' => [
            'middleware' => [
                Application\Middleware\DeciderMiddleware::class
            ],
            'priority' => 10000,
        ],
    ],
];

The only thing you have to do is to define the apiMiddleware and the webMiddleware in the DeciderMiddlewareFactory and initialize the DeciderMiddleware-object with these parameters.