Enforce ResponseInterface from route actions

[geggleto]

Currently, Slim does not enforce developers to return a ResponseInterface from a route callable.

Example:

$app->get('/test', function ($req, $res, $args) {
    print "do stuff";
});

Proper:

$app->get('/test', function ($req, $res, $args) {
    return $res->write("do stuff");
});

What should happen

$app->get('/test', function ($req, $res, $args) {
    print "do stuff";
});

An exception should be raised. \Exception("Response Interface should be returned from a Route Callable");

[silentworks]

This is due to BC, where we allow you to echo instead of return ResponseInterface.

[geggleto]

I thought we had stopped that?

[silentworks]

I don't remember it being removed. Maybe add to the 4.0 Roadmap.

[geggleto]

I would then propose a different Strategy for capturing the buffer output from the callable and pass it down the chain.

ob_start();
$callable($req, $res);
$response->write(ob_get_clean());

[geggleto]

Or we can possibly modify the current one to include a ob_* capture if the callable doesn't respond with a response interface?

[geggleto]

I suppose we could make this a 4.0 thing

[akrabat]

I would then propose a different Strategy for capturing the buffer output from the callable and pass it down the chain.

ob_start();
$callable($req, $res);
$response->write(ob_get_clean());

https://github.com/slimphp/Slim/blob/3.x/Slim/Route.php#L324-L326

This would have to be a 4.0 thing anyway.