Hi! If I understand correctly, this will allow users to provide a default implementation for unimplemented methods by defining the on_request() method in the resource. If implemented, this will be used instead of the default "405 Method Not Allowed" responder.

Regarding on_options() I agree that it makes sense to keep providing the default responder. If needed, on_request() can be called explicitly in on_options().

I believe I can work on this.

Hi @gespyrop! Yes, I was thinking along these lines.

And yes, regarding on_options, it is even easier to do something like

class MyResource:
    def on_request(req, resp, ...):
        ...

    on_options = on_request

However, this issue had no "needs contributor" label, which doesn't mean you aren't welcome, but be prepared for a bit more involved feedback loop wrt the architectural part. 😈
Mostly because we cannot roll this out indiscriminately in a SemVer minor version, since if anyone already had on_request(...) for any other purpose in their resources, that would break the default responders. So we need to gate this new functionality behind an option, probably App.router_options.
Then, if we get positive feedback from the community wrt this feature, we can enable it by default in Falcon 5.0.

Oh, my bad. 😅
A more involved feedback loop is not a problem.

I added an option so that it can be enabled by

app.router_options.allow_on_request = True