[4.x] Decorated Response in case of explicitly set Response Factory

[adriansuter]

Hi there

The problem

When providing a response factory explicitly to the AppFactory::create() method, then the response would no longer be decorated automatically. Is this the expected behaviour?

Say my index.php is as follows (I am using the Nyholm PSR-7 for this example):

declare(strict_types=1);

use Nyholm\Psr7\Factory\Psr17Factory;
use Psr\Http\Message\RequestInterface as Request;
use Psr\Http\Message\ResponseInterface as Response;
use Slim\Factory\AppFactory;

require __DIR__.'/../vendor/autoload.php';

// Explicitly define the response factory!!
$app = AppFactory::create(
    new Psr17Factory()
);

$app->get('/', function (Request $request, Response $response, array $args) {
    $response->getBody()->write(get_class($request).', '.get_class($response));

    return $response;
});

$app->run();

Calling the route returns

Slim\Http\ServerRequest, Nyholm\Psr7\Response

So the request gets decorated (as expected), but the response does not get decorated.

Is this the correct solution?

In order to get the response decorated, we need to do as follows, right?

declare(strict_types=1);

use Nyholm\Psr7\Factory\Psr17Factory;
use Psr\Http\Message\RequestInterface as Request;
use Psr\Http\Message\ResponseInterface as Response;
use Slim\Factory\AppFactory;
use Slim\Factory\Psr17\SlimHttpPsr17Factory;

require __DIR__.'/../vendor/autoload.php';

$responseFactory = new Psr17Factory();
$app = AppFactory::create(
    SlimHttpPsr17Factory::createDecoratedResponseFactory(
        $responseFactory, $responseFactory
    )
);

$app->get('/', function (Request $request, Response $response, array $args) {
    $response->getBody()->write(get_class($request).', '.get_class($response));

    return $response;
});

$app->run();

The result was

Slim\Http\ServerRequest, Slim\Http\Response

If this is the way to go, then this should be mentioned in the documentation I guess. What do you think?

[l0gicgate]

This is the expected behavior. You should use the AppFactory if you want decoration auto detection to work.

[adriansuter]

Of course.

I was wondering how to decorate a response if it was not one of the supported PSR-7 implementations.

Then instead of passing the response factory (neither the decorated nor the non-decorated) to the \Slim\Factory\AppFactory::create() method, I should rather write a psr17 factory for the new PSR-7 implementation that can then be added to the psr17 factory provider using \Slim\Factory\Psr17\Psr17FactoryProvider::addFactory().

Is this right? Should that be mentioned in the docs? If yes, where would that make sense? Probably this is already some advanced stuff?

[l0gicgate]

All you would need to do is create your own ResponseFactory and then you add it via addFactory() as you mentioned yes. Then it will be decorated given that Slim-Http is installed!

We should have a section about the AppFactory in the docs for sure. It's not really something that most people will be actively using though I suspect so I'm not sure how much effort should be poured into documenting it that thoroughly.

Edit:
After reading through the code of AppFactory, I think that some of the internal mechanics for decoration need to change as you pointed out:
https://github.com/slimphp/Slim/blob/4.x/Slim/Factory/AppFactory.php#L77

As seen here, $responseFactory and static::$responseFactory would not be decorated and they should be. The problem is that since the user is only passing in a ResponseFactoryInterface via AppFactory::create() we need to figure out the associated StreamFactoryInterface in order to create a DecoratedResponseFactory instance. That's not possible with the current mechanism. What we could do is add a setStreamFactory() method on AppFactory