Re: [ietf-caldav] draft-daboo-webdav-sync-01

[Roberto Polli <[e-mail]>]

On mercoledì 11 marzo 2009 14:32:24 you wrote:
> > I miss the point:
> > * as of now we can find events by time-range with caldav for queries 1)
> > and 2) using CREATED|LAST-MOD
>
> Hmm, this is rather dangerous since those iCalendar properties are
> controlled by the client, not by the server.
I checked and you're right, but that's not evil.
example:

1) let's assume I got one client and one server in sync at T0
2) let's create 100 items (E1..E100) on client, and trigger a new sync at T1
3) imagine that sync lasts 2 minutes and ends at T3 = T1+120secs
4) there're now events E1..E100 on server that have been created since the 
beginning of the last sync at T2  :  T1< T2 <T3

At next sync I got 2 hypothesis:
-  ask for events created after T0, thus retrieving as new events the ones I 
put there
- ask for events created after T3, thus missing events created on caldav while 
syncing (eg. imagine sync is scheduled each 5minutes)

using a sync engine, I could avoid storing etags data setting CREATED and 
LAST-MODIFIED as T0 while syncing events between server and client. 

In that way all modifications made during sync (should) remain external to the 
changes made by users.

That said, it seems that playing with etags is nicely faster (but needs a sync 
engine) and the only issue remains about time-range filter.

Hope it helps+Peace,
R.



-- 

Roberto Polli
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