[sugar] Issues with the presence service
Marco Pesenti Gritti
Sat Jul 29 13:26:46 EDT 2006
> So how about this for a flow?
> - PS sees new "_tamtam._tcp" service advertised, sends ServiceAppeared
> - Home Page receives ServiceAppeared signal, looks through it's registry
> for Activities that can handle "_tamtam._tcp"
> - Home Page finds the TamTam activity can handle it, and asks some
> TamTam code to thumbnail and display the activity on the Home Page
> My point is that on the activities _themselves_ can know what service
> types the can handle, and how to handle those types. We don't need a
> "default type" passed through the PS, because the local activity knows
> how to handle it. For example, the browser uses "_web_olpc._udp" and
> "_olpc_model._tcp". The Browser activity already knows that the
> _web_olpc._udp service is the "default" service for a browser activity,
> and it can tell the Home Page that without the PS getting involved.
Ah! I had forgot the default type is just the name of the default
service... I need a new brain.
>>>> - There seem to be no way to join an activity other than manually
>>>> duplicate the service. Also should we provide this rather than have
>>>> every activity to reimplement it? In sugar.activity.Activity or maybe
>>>> even directly in the shell...
>>> Well, we _have_ to create a new service when we join the activity, since
>>> we need to change the source address for the service anyway. Even if we
>>> receive a service from the network from somebody else, that service is
>>> "somebody else's" service, and _not_ ours. We have to create a new
>>> service, cloned from the original service, and publish that instead,
>>> because that uses our local information
>> Right, my point was more than we need convenient way to do it (and one
>> that doesn't need a comment to clarify what is going on)...
>> # Ok, there's an existing chat service that we copy
>> # parameters and such from
>> addr = service.get_address()
>> port = service.get_port()
>> self._chat_service =
>> address=addr, port=port)
> Hmm, maybe we should make the Activity base class handle the sharing?
> Because Activity objects already know their default service type,
I think we should do that.
Btw there is join_activity/joinActivity in shell/PresenceService which
seem to be unused?
> and we
> shouldn't be using "share_activity" to publish anything _except_ the
> default service type.
I think that's not the case at the moment... so we should fix it.
There are probably other cases where you will want to "clone and
republish" a service. That might not be frequent enough to deserve a
specific API though, not sure.
> I wanted to get away from having create_service()/create_activity()
> calls that just create the service/activity and then wait for you to do
> something with it. That's pretty useless and encourages bad habits.
> When you create a service, it should be published automatically because
> there's no legitimate reason I can think of that it shouldn't be
> published automatically.
Yeah, that make sense.
Seems like we covered pretty much everything. We just need to go through
this thread and fix up stuff...
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