Feat/allow passing answer from @on to @after hook

[OSkrk]

This PR addresses the feature discussed here, allowing the response sent inside the @on to be passed to the @after hook for further processing (avoiding the use of temp variables). The feature enables the @after decorator to accept an inject_response parameter, which can be used to control whether the response from the _on_action handler is passed to the _after_action handler, and guarantees backwards compatibility.

@OrangeTux , @tropxy, @HugoJP1, @mdwcrft would like to know you guy's feedback on this.

[astrand]

Thanks for working on this!

[astrand]

Not so "elegant" to have 4 calls to handler(). My suggestion is to use keyword arguments instead, like I did in #264 (comment) .

[OSkrk]

This approach was suggested by @tropxy in this comment and clarified by @OrangeTux in a later comment (both authors of this repo). There is no 4 calls to the handler, the handler is only called once depending on the parameters.

[tropxy]

@OSkrk what @astrand is suggesting is something like this (right @astrand ?):

if "call_unique_id" in handler_signature.parameters:
    snake_case_payload["call_unique_id"] = msg.unique_id
if  inject_response:
    snake_case_payload["on_response"] = response_payload

response = handler(**snake_case_payload)

May you try that and see if it works?

Note: I have used your current nomenclature, but if you change the code then "on_response" will be "call_response"

[astrand]

Why check attribute on the handler, instead of checking signature parameters? This opens up for some corner cases, like if inject_response is True but after handler does not accept "on_response" kwarg. Also it is different from how call_unique_id is handled.

[OSkrk]

@astrand , thanks for your comment. Why would you set the flag to True (which defaults to False) to pass the reponse and do not accept it in the @after ?

[tropxy]

can you include notes in the doc strings in respect to the new argument and its purpose?

[tropxy]

It would be better the term "call_response". The "on" prefix is given to functions/callbacks as an action will be performed via that callback function. Here we want to pass an argument..

[tropxy]

@OSkrk what @astrand is suggesting is something like this (right @astrand ?):

if "call_unique_id" in handler_signature.parameters:
    snake_case_payload["call_unique_id"] = msg.unique_id
if  inject_response:
    snake_case_payload["on_response"] = response_payload

response = handler(**snake_case_payload)

May you try that and see if it works?

Note: I have used your current nomenclature, but if you change the code then "on_response" will be "call_response"

[OrangeTux]

I don't have anything against this PR. I leave it up to the new maintainers to approve and merge it.

I'll have a call with the new maintainers this Friday and I'll bring this PR to the table.