James Snell wrote: > Using the x:deleted tombstone element, on the other hand, the spam > entry > only shows up once, at a maximum. Readers that do not understand the > tombstone element would act no differently than they currently do and > users should not see any change in current feed reader behavior.
The "spam-shows-up-more-than-once" idea is not correct, regardless of which tombstone mechanism you use. Even if you hand tombstoned entries to a non-tombstone client, the entry only shows up once. If, as we're recommending, you only give tombstones to clients that ask for them, then there's no entry at all. > Example: we have a feed with two entries. There are two feed reader > clients, neither of which know about tombstones. Client A requests the > feed and sees both entries. <snip> > Client A gets the feed and still sees two entries, one of which is > marked as being updated. > > Client B comes along and requests the feed and see two entries, both of > which are new to it but one of which doesn't actually exist. Why > should > Client B have to see that entry at all? If the entry was deleted, it > shouldn't be in the feed. Agreed. But with the <x:deleted> element, you're still passing unnecessary info to the client. If you go and delete ALL of the entries from the feed, then the client receives a feed with nothing but tombstones, which it didn't want in the first place. In that case, asking the client to opt-in seems like a pretty good idea. > Now use the separate tombstone element, > > <feed> > ... > <x:deleted> > <id>tag:example.org,2007:1</id> > </x:deleted> > <entry> > <id>tag:example.org,2007:2</id> > ... > </entry> > </feed> > > Client A continues to operate as it always has when an entry that was > once in the feed suddenly isn't and Client B never has to see the > deleted entry at all. That makes a whole lot more sense to me. > > Now, Steven indicates that their implementation will not include the > tombstone by default. Clients that want tombstones would have to ask > for > them explicitly. While that would solve the problem, using the > tombstone element would avoid the need to have that kind of negotiation > mechanism at all. Again, the mechanism seems pretty simple to me, and it has the benefit of not passing any tombstones to a client that won't understand them anyway. Steven
