log a warning or error when adding something to blueprint after adding it to application

[fredlllll]

Is your feature request related to a problem? Please describe.
when i add a blueprint to the sanic app, and then add routes to it, those routes dont work. i have to add the blueprint to the app after adding routes. but there is no indication that im doing something wrong if i do it the wrong way

Describe the solution you'd like
log a warning or error message telling the programmer that they added routes to a blueprint after adding it to the app, and that those routes will not work. or straight up throw an error

[ahopkins]

💯

This should be the case for any Blueprint addition (routes, listeners, middleware, exception handlers, signals).

[prryplatypus]

I might give this one a try tomorrow or on Monday

[Tronic]

Or better yet, make the blueprint changes work even after added to an app, if doing so is feasible.

[ahopkins]

Or better yet, make the blueprint changes work even after added to an app, if doing so is feasible.

This could be a bit messy, and I believe would require a bit of a refactor from how the decorators work. I think it also breaks the principle of what the Blueprint is, but perhaps could be doable with something like this:

    def route(self, *args, **kwargs):
        kwargs["apply"] = False
        sup = super().route

        def wrapper(handler):
            retval = sup(*args, **kwargs)(handler)
            for app in self.apps:
                self.register(app, {})
            return retval

        return wrapper

If we are going this direction, then we need to definitely beef up the unit testing around this, and probably make all of these methods (route, static, middleware, exception, signal) perhaps a little more DRY.

[ahopkins]

@prryplatypus I am going to take this one myself. I hope you do not mind.

[prryplatypus]

All good!