CommentAPI namespace support

[mpgirro]

The CommentAPI namespace is used to expose the URL endpoint for posting comments. The URI is http://wellformedweb.org/CommentAPI/. 24,6% of feeds declare the namespace, so it's pretty common.

The wellformedweb.org domain is down, and the namespace is otherwise not very well documented, but I still found some info. The wayback machine shows the original spec. The only element it defines is the wfw:comment element in the <item>, but it's used in < 0,1% of feeds. Back in 2003, Chris Sells proposed an additional element wfw:commentRss, which is used in 8,4% of feeds (also < 0,1% use the wrong wfw:commentRSS).

Chris Sells also mentions that his element is for an item-level comment endpoint URL, but as I understand the CommentAPI spec, the wfw:comment basically does the same. Right now I'm a bit confused here what the actual difference between the two elements is.

Example:

<wfw:comment xmlns:wfw="http://wellformedweb.org/CommentAPI/">
  http://bitworking.org/news/comments/52
</wfw:comment>
<wfw:commentRss xmlns:wfw="http://wellformedweb.org/CommentAPI/"> 
  http://bitworking.org/news/commentsRss/52
</wfw:commentRss>

[rock3r]

For what I understand, the difference is:

• wfw:comment points to a REST endpoint that you can POST to, in order to submit comments for a certain item
• wfw:commentRss points to a secondary RSS feed that serves existing comments for a certain item

This means, they are complimentary. It would make sense to implement them both, while we're at it — they're pretty simple, at any rate — although I completely understand why many more feeds would expose the "read" URL tag (wfw:commentRss) but not the "write" URL tag (wfw:comment): for readers and aggregators that's much more useful.

[mpgirro]

You are totally right, should have read the third paragraph and not just skip over the HTTP examples 😅.

I'd definitely implement them both. In general, a frequency < 0,1% does not discourage me from supporting something. If there is no parser/writer support for something, almost nobody will use a standard, and I'd like to change that :)