Re: The distinction between "time this entry was published" and "time this entry was added to this feed"

["James Holderness" <j4_james@xxxxxxxxxxx>]

Martin Atkins wrote:
> Consider for example the feed that YouTube publishes of a user's "Favorite 
> Videos". In this feed, the entry-level atom:published tells us when the 
> entry was added as a favorite, *not* when the entry (i.e. the video) was 
> posted to YouTube by its author.

Without answering you directly, I'd like to comment on YouTube's feeds, 
because I think what I have to say is relevant to the way you might go about 
creating feeds for activity streams.

Imagine I know someone that has a knack for finding good videos on YouTube, 
so I subscribe to their favourites feed to keep up with all the cool stuff 
they've discovered. I also subscribe to the YouTube "Recently Featured" 
feed, for similar reasons. And finally I subscribe to a couple of individual 
feeds for users who are friends.

Now imagine one day that one of my friends produces a really good video. 
It's spotted by the person whose favourites I subscribe to, as well as being 
a featured feed. That means the entry is going to show up in three of my 
feeds. Identical content, linking to an identical page, repeated three 
times. How many times do you think I want to view that entry?

You might be thinking, that's exactly what the atom:id element is for - my 
feed reader should be able to detect that all three entries are the same 
since they should have the same id value. Only they don't have the same 
value. Each one has a different id, so I get to see the exact same entry 
repeated three times. Saying that this is annoying would be a huge 
understatement.

Where this is relevant to your question, is that if you change the published 
date from the original entry (as YouTube is doing - at least for their 
favourites feeds), you basically have to change the entry id, since you're 
now no longer dealing with the same entry. And that, as I've said, would be 
incredibly annoying.

If you think that's a worthwhile compromise for your needs, that's your 
choice to make. I'll just weep quietly in the corner.

Regards
James