Simplifying queuing middleware

[adriansuter]

This issue is similar to slimphp/Slim#2762.

With the solution proposed in slimphp/Slim#2762 (comment), a user could for example just write

$app = AppFactory::create();
$app->addRoutingMiddleware();
$app->addErrorMiddleware(true, true, false)
    ->getDefaultErrorHandler()->forceContentType('application/json');

and only AppFactory needs to be imported. That is pretty nice for these two internal slim middlewares.

I wonder if we could simplify the other middlewares as well. I mean, for example, to add the twig middleware, a user has to write the following code.

$container = new Container();
AppFactory::setContainer($container);

$app = AppFactory::create();
// Let's add the routing middleware. Nice.
$app->addRoutingMiddleware();

// Let's add the twig middleware. Complicated.
$app->add(new TwigMiddleware(
    new Twig(__DIR__ . '/../templates', [
        'cache' => __DIR__ . '/../cache/twig',
        'auto_reload' => true,
    ]),
    $app->getContainer(),
    $app->getRouteCollector()->getRouteParser(),
    '',
    Twig::class
));

// Let's add the error middleware. Nice.
$app->addErrorMiddleware(true, true, false);

We could for example let the user add twig to the container and then he/she can simply call

$app->add(TwigMiddleware::create($app, $basePath, $twigContainerKey));

The static create() method would then get the container from the app, twig from the container, and the route parser from the app (via route collector). Of course, the method would throw exceptions whenever anything is missing (no container, twig not found, etc.).

[l0gicgate]

Yes, let's do that as well. This will simplify everything for the end user tremendously.

[adriansuter]

Handled in #120