#547 clarify PUT on content negotiated resource

<http://trac.tools.ietf.org/wg/httpbis/trac/ticket/547>

During IESG revied, Ted Lemon came up with this question:

> The paragraph crossing the page break at the bottom of page 16 (ed: <http://greenbytes.de/tech/webdav/draft-ietf-httpbis-p2-semantics-25.html#rfc.section.3.1.4.2.p.8>):
>
>    For example, if a client makes a PUT request on a negotiated resource
>    and the origin server accepts that PUT (without redirection), then
>    the new state of that resource is expected to be consistent with the
>    one representation supplied in that PUT; the Content-Location cannot
>    be used as a form of reverse content selection identifier to update
>    only one of the negotiated representations.  If the user agent had
>    wanted the latter semantics, it would have applied the PUT directly
>    to the Content-Location URI.
>
> It's good that there's an example here, but this creates more questions than it answers: if I do a PUT to a particular URI, for which there are currently multiple representations of the document in different languages, based on a GET that had a specific language representation, is the semantics being specified here that the other language representations go away? That's kind of what it sounds like. This text makes sense for different content encodings like JSON and XML, where the server might be able to generate one from the other, but it's giving me a headache thinking about it in terms of natural language. Am I missing the point here? If so, could this be clarified, or did I just not drink enough coffee this morning?

To which I replied:

Mainly it means that it's a bad idea to do it, unless the other language 
versions are automatically updated somehow. The main point is that if 
you want a single variant of a content-negotiated resource to be 
authorable, you better serve it with a specific Content-Location, so 
that the authoring client then can use the specific URI to update just 
that variant.

Ted replied to that with:

 > Hm, so then why not say so more explicitly?

Not sure about that. Maybe there are use cases I'm not aware of.

What do other think? Should we rephrase this?

Best regards, Julian

Received on Friday, 10 January 2014 18:12:46 UTC