[vos-d] S5 and ordering listeners

[Peter Amstutz]

On Mon, Oct 22, 2007 at 04:39:39PM -0400, Reed Hedges wrote:
> 
> Can you comment on this Peter?
> 
> Let's say I want a set of listeners attached to an object to be 
> invoked in order. Let's say that both listeners live on the same local 
> site (process) and maybe are both associated with the same vobject.  
> Will there be a way to do this in S5? What if the listeners are 
> associated with metaobject types (e.g. a vobject L is linked to 
> another vobject "Source". Applying type X to L causes listener x to be 
> created, and applying type Y casues listener y to be created, each 
> listening to vobject Source (they find Source because it's linked to 
> L). I always want x to be notified before y of any changes to Source.
> 
> Does this make sense?

I don't really follow, no.  Could you give an example?

The plan for listeners is for it to be based properly on message passing 
between objects, rather than straight callbacks.  Once messages are sent 
out, there isn't really a guarantee on ordering, so if you need a strong 
cause and effect trigger, you should probably have an intermediate 
object that subscribes to the primary object, does some work, and then 
passes it on to the next listener...

Or are you trying to do some kind of filtering?

I can't answer the questions without knowing what you're trying to 
acomplish.

-- 
[   Peter Amstutz  ][ tetron at interreality.org ][ peter.amstutz at gdit.com ]
[Lead Programmer][Interreality Project][Virtual Reality for the Internet]
[ VOS: Next Generation Internet Communication][ http://interreality.org ]
[ http://interreality.org/~tetron ][ pgpkey:  pgpkeys.mit.edu  18C21DF7 ]

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