[pulseaudio-discuss] [PATCH 4/6] core: add message handler

[Georg Chini]

On 03.10.2017 14:58, Tanu Kaskinen wrote:
>
>>> Also, it's questionable why the list-handlers command is implemented
>>> with the messaging API in the first place. It's core functionality, so
>>> why is it not implemented using the normal introspection API?
>> Two reasons:
>>
>> a) It's much simpler than using the introspection API
> Ok, but didn't we agree earlier that the messaging API is only meant
> for modules, and new core features shall be added using the existing
> API conventions? The rationale, if you've forgotten it, was that it's
> annoying for application developers if the core API uses inconsistent
> conventions and introspection functionality needs to be searched from
> two different places.
>
> I might accept it if you put the client-facing bits in the
> introspection API, but use the messaging system behind the scenes. If
> you want pursue that route, I'd like get an ok from Arun as well. This
> is not only about the list-handlers message, it's about all future core
> features.
>
> Another possibility is to deprecate the whole introspection API and
> reimplement it using the messaging API, but you probably don't want to
> take such a big project.
>
>> b) We should at least have one example in the code
>> which shows how a message handler is implemented.
> It's certainly good to have an example now so that we can discuss how
> the message parameter serialization is supposed to work, but I don't
> think we need to apply that example to master. I hope we'll have some
> other example by the time 12.0 is released (IIRC, you plan to add a
> message handler to module-loopback), but it's not a big deal if there
> are no examples.
>
Finally I found some time to work again on the message patches.

There is a third reason why I think getting the message handlers
should be implemented using the message API:
The message delivers information about the message API itself
and the information should be accessible via that API.

So is it OK if I keep the message handler implementation (provided
that the handler returns a more "machine readable" format)? Or will
you reject it?