[Standards] Proposed XMPP Extension: Metacontacts

Mridul Muralidharan mridul at sun.com
Tue May 8 18:16:14 UTC 2007

Please see below.


PS : My client messed up and I did not see this until now, apologies for 
late response.

Pedro Melo wrote:
> Hi,
> On Mar 29, 2007, at 4:35 PM, Mridul wrote:
>> Ian Paterson wrote:
>>> PEP also gives us a registry of well known nodes.
>> private data is going to be specific to a application in most cases.
> That's no longer true with recent protocols like multi-contacts, right?

I am yet to look at this xep ... I am sure there will be applications 
which will immensely benefit from PEP, no disputing that : I have my 
favorite for pep too.
But it should be kept in mind that not all solutions need the extra 
complexity, there are usecases for which push is not very useful : will 
it benefit from a push ? Anything could be made to benefit - ignore if 
not required at degenerate case ! But is it worth the added complexity ? 
I am not sure.

Take client prefs stored in private storage for example, what I normally 
see stored there is application specific information - (x,y) coords, 
window attributes, and similarly other sundry housekeeping information 
specific to a client.
Does this really require a push across clients ? I seriously would doubt 

>> So I am not sure why we would need this ...
>> Typically pref's for gaim would not be useful for sun im
>> client/exodus/psi/etc.
>> The data which is going to be reusable is already standardized (or could
>> be) like bookmarks, etc.
> And bookmarks should be private right? and probably would be great to 
> keep them in sync? That's why we see PEP as a replacement for 
> jabber:iq:private.

It just so happens that, since private storage was the only mechanism 
available for storage until PEP came into the picture, extensions which 
really dont fit private storage got modeled on top of it : had we had 
pep before, I am sure they would have been designed differently.
If I was thinking of bookmarks today, I would prefer pep over private 
storage to leverage the push across resources.

It is similar to the 1 to 1 chat, vs muc example I mentioned elsewhere.
If I just want to chat with a contact, I would use direct <message/> : 
even though I could very well be using a private conference for this 
through muc too.
I am not very sure if the extra complexity of pep is worth it for a lot 
of usecases where you just want to dump some data at the server as 
storage for later retrieval.
Client/user preference is a good example of this.


> And also because the alternative is to build 
> jabber:iq:private:with:notif that in the end will be a subset of PEP...
> Best regards,
> --Pedro Melo
> Blog: http://www.simplicidade.org/notes/
> Jabber ID: melo at simplicidade.org
> Use Jabber!

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