[5.0] Implemented Kernel::addMiddleware method to add middleware at runtime.

[jasonlewis]

As per title and previous issue #6211.

This first checks to see if the middleware is already in the stack before adding it. This allows a custom order if it's required, otherwise it just adds it to the end.

[jasonlewis]

The only other thing I was tempted to do is perhaps bind the kernel to the container as kernel, this would avoid having to do the following.

$this->app['Illuminate\Contracts\Http\Kernel']->addMiddleware('FooMiddleware');

It would instead be...

$this->app['kernel']->addMiddleware('FooMiddleware');

[crynobone]

should just @return $this i think

[jasonlewis]

Aye, fixed. Cheers mate.

[barryvdh]

Would it perhaps make sense to make it possible to determine the order of the middleware? Eg. public function addMiddleware($middleware, $prepend = false) or something, so you can add a second parameter to put the middleware in front of the list, instead of the end.

[lucasmichot]

Makes sense @barryvdh ,
I would go further and say we should have addMiddleware, appendMiddleware, prependMiddleware

[barryvdh]

Wouldn't add and append have the same effect?

[lucasmichot]

Yes mistyped addMiddleware => appendMiddleware, prependMiddleware

[jasonlewis]

Yeah I was contemplating that as well. Go that route you reckon?

[taylorotwell]

To keep our terms consistent we may want to use "pushMiddleware" for adding to the end (like session push method), and then prependMiddleware for adding to beginning.

[kaidesu]

pushMiddleware and prependMiddleware would be ideal for sure.