Note that the pace text doesn't mention sync'ing. This pace is not designed to provide a solution to the complete sync problem. It is, however designed to provide some useful metadata in the entries (app:modified and app:revision are good for more than just sync'ing)
Thomas Broyer wrote: > > -1 > comments below > > 2006/7/11, James M Snell: >> Having a way of indicating the date the entry was last modified is a >> good optimization to avoid having to HEAD each individual member URI to >> get the Last-Modified header. > > app:modified cannot be mandatory when used in an entry from within a > feed. It's a good optimization to know *which* entries to > "conditionnaly GET", only as mean of knowing where to stop > "conditionnaly GETting" entries when "paging" the feed (i.e. as soon > as you find an entry with an app:modified grater than or equal to –to > account for the "modified twice a second" use case; and even when the > date-time precision is beyond the second, the entry could still have > been changed twice a millisecond…– the last time you sync'ed with the > server. > This pace does not make app:modified mandatory. Nor do I make any assumptions that app:modified is authoritative. TAG finding 10 is very clear on that point. > This does not prevent using ETags in conditional GETs to update your > local cache and in PUTs to avoid lost updates. > >> Having a way of associating a unique revision token with an entry is >> also useful. > > Don't see the need… > I said "useful" not "required". :-) >[snip] >> == Impacts == >> >> Very little. Use of the elements are optional. > > If entries are ordered by atom:updated, you'll still have to GET the > whole feed to find each "modified but not updated" entry. Clients > might find it better to finally GET the feed only to detect new > entries and otherwise conditionally GET each known entry to retrieve > the latest "revision". > Yep. Again, I'm not interested in solving the sync problem in the app spec. At this point, all I want is to provide some useful metadata and get out of the way. - James
