RealtimeChannel: duplicated publish method

[ricardopereira]

Code completion:

The RestChannel is the base class of the RealtimeChannel. RestChannel has 4 publish methods that we already discussed on #121.

Problem:
The RealtimeChannel does not override those methods and use their own. It should override them and avoid calling the super implementation.

IMO, we should fix #121 first.

[mattheworiordan]

Agreed that #121 should be fixed first

[tcard]

I think the deeper problem is, why is RealtimeChannel inheriting from RestChannel? You can't use a RealtimeChannel as a RestChannel. If anything, both should inherit from a BaseChannel or implement a Channel protocol.

I strongly think that this should be fixed.

[mattheworiordan]

I think the deeper problem is, why is RealtimeChannel inheriting from RestChannel

This is mostly because they share functionality such as history. However, as you say, that could be part of the BaseChannel implementation instead.

[tcard]

To reuse code, it is a very well-established "principle" to use composition over inheritance. Anyway, to not get sucked into the rabbit hole, I would be happy with inheriting from a BaseChannel.

[mattheworiordan]

To reuse code, it is a very well-established "principle" to use composition over inheritance.

Sure, we do that in our Ably libraries. If that's easy enough to do in Objective-C, sure, although I suspect we're largely using inheritance elsewhere

[ricardopereira]

Yes, it is largely using inheritance, e.g.: ARTBaseMessage.
I liked the use composition to fix this more than the ARTBaseChannel but I can do it for now.

@tcard So you mean something like ARTChannelHistory.history(...)?

[tcard]

@ricardopereira I guess. Or even RealtimeChannel having a RestChannel property, because AFAIK RealtimeChannel just calls the REST API for history, right?

[ricardopereira]

Yes, you right.

[tcard]

Fixed by 97f0b16.