[5.5] Add ability to set a fallback route

[themsaid]

This was requested in:

• [Proposal] Route::fallback(); ideas#653
• Adding Route::other for setting route that matches all the requests that didn't match ideas#780

The idea is to have a catch-all Route that you can use as a fallback if the request didn't match any of the existing routes, so for example:

• dashboard/non-existing will throw a 404 and render the 404 view if no fallback route is used.
• If we use Route::fallback(function(){ return response()->view('dashboard.404', [], 404); }) the dashboard specific 404 page will be displayed.

In the argument you pass to fallback() you can put a closure or a controller call DashboardController@notFound, this will allow you to render a Not Found page with the request passing through all middleware so you have sessions, cookies, etc... available.

So for example in Forge, if a logged in user hit a wrong URL we can display a 404 view but he still has access to the header where he can browse to any of the existing screens.

[paulofreitas]

Just for completeness this was also proposed at PR #20923 (closed). Nice to see this feature request being considered again. 👍

[themsaid]

@paulofreitas didn't know there was a PR already, this one is similar with the difference that it makes sure your fallbacks URL are sorted at the very end of the routes collection so that a custom wild-card route would match first before using the fallback route.

[laurencei]

The idea is to have a catch-all Route that you can use as a fallback if the request didn't match any of the existing routes

So what is different about this vs just overriding the 404 handling?

public function render($request, Exception $e)
{ 
    if ($e instanceof NotFoundHttpException) {
        if (Auth::user()) {
            return response()->view('errors.404.user', [], 404);
        } else {
            return response()->view('errors.404.guest, [], 404);
        }
    }

    return parent::render($request, $e);
}

[themsaid]

@laurencei in error views you don't have access to sessions, basically no middleware runs.

[laurencei]

Arh yep, of course 😃

[deleugpn]

I also liked #20923 a lot. I've been using it since that PR was created.

[thecrypticace]

A bit of an open-ended comment: sort takes two parameters to compare and, iirc, ignoring the second one (by not properly returning 1 or -1) can result in what appears to be a somewhat randomized order.

Perhaps you should do $routeA->isFallback <=> $routeB->isFallback? I'm going to try and write a test to verify this theory (so such a change could be caught in the future)

[deleugpn]

Spaceship!

[decadence]

@themsaid Thanks

[zzal]

Look like the fallback() method will only result in GET and HEAD methods.
Is there a way to include POST and DELETE?

[staudenmeir]

@zzal See #25555.