[jdev] JEP--0060 implementations?

Ralph Meijer jabber.org at ralphm.ik.nu
Wed Jun 23 08:11:01 CDT 2004

On Wed, Jun 23, 2004 at 01:41:52PM +0100, Phil Wilson wrote:
> [...]
> > By the way, Mimir is not a pubsub service, it /uses/ pubsub, 
> > and currently it
> > uses Idavoll for the pubsub service. 
> But to a Jabber client, this is transparent isn't it? i.e. it just appears
> to be A.N.Other pub/sub service?

When, actually not (yet). For now Mimir uses the pubsub service (in this
case Idavoll) to subscribe to news sources. The core of Mimir is,
if you look at the diagram on http://mimir.ik.nu/about, the news bot with
associated database and web site. You can view this as a pubsub client.

The part to the left of that is a system to use legacy news sources like
RSS files. The aggregator polls RSS files and publishes the news to a
pubsub service. This is a client, too.

If you look at it more abstractly, the news bot plays two roles.

First, it allows users to subscribe to certain channels and let exisiting
clients receive plaintext notifications (instead of pubsub notifications). So
actually, this part is a gateway to the human world, and really a
reimplementation of a pubsub system using other protocols (the website
where you can subscribe to channels, and the normal chat messages). It
proxies real (ie. JEP-0060) pubsub notifications and translates them on the

One extra feature there is that it is actually a filtering proxy, in that
it uses presence to determine whether to relay the pubsub notification
to a certain user.

Second, each publish has a side effect. All items received by the bot
are stored in a database, and, when the user didn't receive the notification
because of presence, it marks that item as being unread for that user. The
user can at a later point read the item via the web page.

The next generation version of Mimir might actually use more of the
pubsub protocol to do this, and allow custom clients to receive real pubsub
notifications. Think of it as a desktop news aggregator that gets the news
pushed instead of having to pull for it.

> > Pubsub.com as far as I can see, is tailored to the pubsub.com 
> > application and not a generic pubsub service anyone can use for their own 
> > applications (Bob, correct me if I'm wrong).
> That's the way I understand it, but they're also the only services which
> provide pub/sub that I could think of, and was hoping there might be some
> more. :)
> > May I ask why you asked?
> I just wanted to see what pub/sub services there were out there and see if
> it was worth writing my own or whether I could piggyback on someone else's
> code, basically. :)

Depends on what you need for your application. For example, my web site
subscribes to peoples User Mood (JEP-0107), and dislays it in the Jabber
World Map, Fish Tank and on http://ralphm.net/moods. Just as for Mimir,
it uses a generic pubsub service to do its job. People create their mood
pubsub node somewhere (currently on my server, but could be anywhere) and
I let the mood bot subscribe to this node. All incoming notifications are
stored in a database that is read by the web site.

No special features needed on the pubsub service.

I hope this helps, please ask more if you still have questions.



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