Re: Why MD5 Headers are Imperative

Tim Bray wrote:

> Some of the discussions on APP have argued out that for an authoring 
> client to do synchronization, they need to get a reliable last-modified 
> timestamp of an entry, and there are a bunch of proposals on the table 
> to handle this, and I have the unenviable task of wading through and 
> figuring out if any of them have rough-consensus support.
>
> However, it is clearly the case that RFC4287 and APP could end up with 
> different notions of last-modified.  Is this a problem? -Tim

Probably. It will tend to happen in enterprise CMS scenarios where there 
is a distinction between document authoring, content management and 
publication to downstream targets, where there are delays due to 
timezones, search engines getting reindexed, staging preview, batched 
publication, external and offline editors, etc (yep, there are lots of 
systems out there that have these characteristics*). This results in a 
big enough temporal gap to matter between an authoring modification and 
a publishing update. I expect that will result in the developers getting 
called in and roasted by the content owners, whereupon they will have to 
start explaining things as follows, "Well, it depends on what you mean 
by modified...". Between Atom and APP there does seem to be a bias that 
we are doing live editing online - that's not a "bad thing", but I think 
it is an important assumption.

I don't think we'll get suitable consensus on synchronization. I would 
love to have it, but we will here in 2008 getting it sorted. I would 
settle for a "POST to edit" idiom to bust cache.

cheers
Bill

* I suspect Eric Scheid might be the other person in the room who has to 
worry about this kind of complexity.