[Ietf-caldav] Plone + CalDAV: periodic versus live/cached

[Graham Perrin]

On 27 Nov 2007, at 19:32, Jeffrey Harris wrote:

>> 2)  ... I'd like Plone to simply present, for an ATEvent object,  
>> event-related information that is drawn from a CalDAV server.
>
> Do you want to draw events live from a CalDAV server, blocking page  
> rendering while you wait for a response from the CalDAV server?  Or  
> were you thinking you'd schedule a periodic task to update Plone?

A good question.

Periodic tasks may be a fine approach to (2) above or (3) below ...

>> 3) Even better: beyond simple presentation, I'd like Plone to have  
>> the ability to update its ATEevent object, based upon what's fed  
>> by the CalDAV server.
>>
>> 4) Best: I'd like changes fed by a human to an ATEvent object to  
>> be relayed appropriately to a CalDAV server, but that's probably  
>> over-ambitious at this time.

... but expanding my thoughts to the future possibility of (4), my  
_instinct_ is that periodic tasks may introduce complications in  
unexpected ways.

Better, I suspect, to allow direct communication between Plone and  
the CalDAV server.

> blocking page rendering while you wait for a response from the  
> CalDAV server?


I guess, Plone can be configured to fall back to cached data when a  
CalDAV server does not provide a timely response.

So ... thoughts forming, _maybe_:

  * Plone should have the option of storing within the ZODB (Zope  
Object Database) a CalDAV URL-oriented object

and

  * that object should include a cached copy of data from the CalDAV  
server

and

  * an ATEvent object may be related to that CalDAV URL-oriented object.

and

  * communication between Plone and CalDAV server to be triggered by  
events, Python/Zope/Plone/workflow experts (not me) will surely have  
a grasp on that side of things.

Regards

Graham