Proposal: Mapping path prefixes to middleware stacks

[franzliedke]

I will happily implement this and send a pull request, if you agree with the idea.

What do you think about something like this?

$broker->paths([
  '/foo' => $myMiddlewareStack,
  '/bar' => MyMiddleware::class,
  '/baz' => 'baz.middleware.stack'
]);

Array values can be middleware, or strings which would then be lazily resolved from the container, whenever a request with this prefix arrives.

This method would have to take care of stripping the path prefix from the request object.

[franzliedke]

A little bit of background: If it had this functionality, I would gladly use this library in Flarum in order to use PSR-15 middleware. We're currently using Zend's Stratigility, but their PSR-15-compatible version does not support PHP 7.0, which is - currently - still a requirement on our side.

[shadowhand]

Would adding this functionality introduce new dependencies? I like the idea of it.

For whatever it's worth, the functionality is already possible by doing something like this:

$broker->when($this->matchesPath('/foo'), MyMiddleware::class);

Assuming that:

private function matchesPath(string $path): callable
{
    return static function (RequestInterface $request) use ($path): bool {
        return strpos($request->getUri()->getPath(), $path) === 0;
    };
}

[franzliedke]

I would implement it without external dependencies.

Stratigility additionally strips out the path prefix from the request - which is very useful because the middleware does not need to know about the prefix. So just matchesPath is not enough.

@shadowhand Is that a "go ahead" then? 😀

[shadowhand]

@franzliedke sure, I'd definitely consider a PR. Seems like it will be reasonable.

[franzliedke]

Little status update:
I got path matching working. The only thing remaining is to change the request's URI object so that subsequent middleware does not have to know about the path prefix.

[shadowhand]

Closing, see discussion on #7