Dear Julian
Thanks for answering my message.
I have finished reading the references about ETags and also ported
libgcal to new Google API Protocol 2.0.
http://repo.or.cz/w/libgcal.git
As I understood, ETags will only be useful to make optional edit/
delete of entries (being calendar events or contacts) when they were
updated in server. And also to query by a unique entry.
But this *doesn't* cover the case that I explained in my first
message, which basically is about detecting if a deleted entry was
present when I last did a synchronization with my google list of
contacts.
I could maintain a table of IDs to solve this, but using this formula
would be way more efficient (suggestion by a fellow hacker):
"If published > last_sync and deleted > last_sync then ignore"
I do query by changes using the timestamp of last-updated entry, to
make possible do fast-sync (instead of dumping all contacts over-and-
over-again).
I'm trying to make this work with opensync, further details can be
found here:
http://opensync.org/ticket/1051
Do you have any suggestion?
Best regards
Adenilson