On 8/27/07, Nikunj Mehta <[EMAIL PROTECTED]> wrote:
> In that case, how can you correctly interpret rel="next" as "paged feed"
> allows lossy feed paging and "collection feed" requires lossless paging?

Sorry, but the feed paging in AtomPub is "lossy" if you follow the definition
of "lossy" in RFC 5005:

"""Paged feeds are lossy; that is, it is not possible to guarantee that
   clients will be able to reconstruct the contents of the logical feed
   at a particular time.  Entries may be added or changed as the pages
   of the feed are accessed, without the client becoming aware of them.
"""

That is, if I break my paged AtomPub feeds into pages of 10 entries
each and if client A is trying to do a sync and client
B edits an old entry in the middle of the process then it is possible
that client A will miss some entries. For example, if my site has 20 entries
broken into two pages:

Page 1      [e0, e1, ... e9]
Page 2      [e10,e11,...,e19]

If client A requests Page 1 and shortly after client B
edits e11 then we get:

Page 1      [e11, e0, e1, ... e8]
Page 2      [e9, e10,...,e19]

When client A requests Page 2 it will miss e11. It will
also see e9 a second time. If I were writing a client
and wanted to make sure I got a good sync I would
finish a first pass at the sync and then go back to the
beginning and do a sync again until I saw an entry I
recognized, in this case e0.

   -joe

-- 
Joe Gregorio        http://bitworking.org

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