[Dev] Services, CPIA, Content Model intercommunication

[Donn Denman]

I was envisioning something like this (but could be completely wrong 
about how these things work):  When you want to share an item you put 
it into the "inclusions" of the Shared Items collection.  That would 
trigger a notification since any change to a collection notifies its 
subscribers.  The Sharing Services would get a notification, look at 
the collection, see that there were "inclusions" and initiate sharing 
of the item.  That would cause the "isShared" attribute to be turned on 
for the shared item, and it would move from the "inclusions" part of 
the collection to being an item generated by the rule (query) of the 
collection.  Similarly putting an item into the "exclusions" list of 
the Shared Items collection would trigger cessation of sharing that 
item by the Sharing Services layer.

In theory these collections can get huge without any performance issue, 
so we could use the natural implementation outlined above.

- Donn

On Nov 8, 2004, at 12:15 PM, Bryan Stearns wrote:

> I'm not sure the collection-query-as-notification-conduit idea works 
> for a
> "shared items" collection...
>
> The query's purpose is to let the service know that there are items
> requiring action. The query is tied to a refcollection in the 
> repository,
> and we want these to be small and simple for the repository code to
> maintain.
>
> So I'd expect that, in the mail example, the refcollection would be a
> specific one set up for this purpose - that is, it wouldn't be a 
> specialized
> query on the user's Out box (which could get rather big). Applied to
> sharing, I think the collection becomes "items needing synchronization 
> to
> the server where this item's ItemCollection is shared".
>
> (or maybe I'm misunderstanding how we use queries... my brain needs a 
> good
> washing.)
>
> ...Bryan
>
> -----Original Message-----
> From: dev-bounces at osafoundation.org 
> [mailto:dev-bounces at osafoundation.org]
> On Behalf Of Donn Denman
> Sent: Monday, November 08, 2004 11:40 AM
> To: Ted Leung
> Cc: OSAF Development
> Subject: Re: [Dev] Services, CPIA, Content Model intercommunication
>
> Comments on applying this model to Sharing below.
>
> On Nov 8, 2004, at 11:09 AM, Ted Leung wrote:
>
>>
>> 1. It seems to me that Bryan's suggestion for using query triggered
>> notifications for inter layer/inter parcel communication is a
>> fundamental architectural pattern for Chandler.  This is something
>> that hasn't quite sunk into our thinking -- most of us were familiar
>> with the general notions (especially having been in the meeting on
>> notification), but it still didn't leap to mind as the first solution
>> (at least for me).  So I think it's worth stating/re-stating this
>> principle, as well as documenting it.
>>
>
>> On Nov 5, 2004, at 12:34 PM, Brian Kirsch wrote:
>>
>>> Another good suggestion was made that perhaps sharing would be a good
>>> first candidate for implement this new design since much of sharing
>>> is being reworked anyways and it does not have the complex
>>> dependencies the mail service does (Twisted, Threaded commits,
>>> Repository view setting and unsetting).
>>>
>>> Thoughts on the proposal?
>>>
>
> We could initiate sharing by having a Shared Items collection, and 
> when you
> put items into it, that initiates the sharing.  Removing items from the
> collection would terminate sharing.  This somehow seems simpler than 
> Mail,
> and we could work out the issues with the collection-based 
> notification in
> this environment, then apply the pattern to Mail.
>
> - Donn
>
> _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
>
> Open Source Applications Foundation "Dev" mailing list
> http://lists.osafoundation.org/mailman/listinfo/dev
>