Re: [wsn] Subscribe and GetCurrentMessage

[Samuel Meder <meder@mcs.anl.gov>]

Another way of doing this that does not require WSRF-RP is to model your
topics in a way that allows for this: A top level topic for the whole
document (which you can call getCurrentMessage() on) and sub-topic for
fields in the document (which you would subscribe to), or even just a
single "update" sub-topic. That in combination with appropriate use of
timestamps should be able to address your problem.

/Sam

On Tue, 2004-11-23 at 16:43 -0500, David Hull wrote:
> Steve Graham wrote:
> > 
> > David Hull <dmh@tibco.com> wrote on 11/22/2004 04:48:34 PM:
> > 
> > > One useful pub/sub paradigm involves the concept of notifications
> > as updates to 
> > > some collection of state. 
> > Indeed, this is what WSRF-Resource Properties suggests. 
> > 
> > > In such cases, it is useful to be able to take a 
> > > snapshot of the state, then be notified of updates to that state. 
> > Agreed.  GetResourcePropertyDocument, followed by a subscribe
> > operation specifying 
> > which Resource properties (bits of state) the consumer should
> > receive value change 
> > notifications. 
> Minus whatever changes happened between the get and the subscribe.  Or
> plus whatever changes happened between the subscribe and the get.  In
> any case, we want to be able to cover snapshot/update scenarios where
> the state is not presented as a WS-Resource.  Or at least I would like
> that.
>