Allow alt_response on MethodView

[der-joel]

It would be a nice enhancement to allow the usage of the alt_response-Decorator on MethodView-classes.
It could act as a shortcut to decorating every endpoint of the view with alt_response.

An example use case would be a custom converter that rejects any pet_id not present in the pet database.
Since its declared in the route-decorator, every endpoint will raise 404 if the pet was not found:

@blp.route('/<object_id(must_exist=True):pet_id>')
@blp.alt_response(404, ErrorSchema)
class PetsById(MethodView):

    @blp.response(200, PetSchema)
    def get(self, pet_id):
        """Get pet by ID"""
        return Pet.get_by_id(pet_id)

    @blp.response(204)
    def delete(self, pet_id):
        """Delete pet"""
        Pet.delete(pet_id)

[lafrech]

This makes sense. I have a few other things listed for alt_response (#256, #260). We could do this as well.

Would you like to investigate any further?

[zedrdave]

From what I can see, this feature has been added now?

Unfortunately it seems like adding alt_response on MethodView makes method-level response get ignored… Is this intended?

If not, should I file a separate issue or is this already listed (I couldn't find anything)?

Edit: in fact, it seems like all method-level annotations (eg Docstrings) get ignored when providing a class-level alt_response… Obviously that seems undesirable and a bug 😅

[lafrech]

I don't remember but from your findings, the use case is still unsupported. It just seems to work but screws everything up.

Let's keep the discussion in this thread.

[zedrdave]

Thanks! My bad then: just assumed it had been implemented, but if it's still WIP, feel free to ignore the above comment 😉

[lafrech]

No pb. Your comment may help someone facing the same issue.

As you can see, it is not really in progress, unless someone wants to take charge.