Re: WGLC review of p2-semantics (editorial stuff)

On Wed, Oct 31, 2012 at 2:13 AM, Julian Reschke <> wrote:
> On 2012-10-30 21:40, Zhong Yu wrote:
>> Got it. In the spec,
>>> Additional header fields define metadata about the selected
>>> representation, which might differ from the representation included in the
>>> message for responses to some state-changing methods
>> So if the current representation has ETag=v1, and PUT sends a new
>> representation to which the server assigns ETag=v2, the response to
>> PUT may contain ETag of the old representation. (This was not in
>> RFC2616)
>> ...
> Why would it contain the old ETag?

According to the same section in the spec

>We use the term "selected representation" to refer to the the current representation of a target resource that would have been selected in a successful response if the same request had used the method GET and excluded any conditional request header fields.

In my example, the request is
    PUT /resource HTTP/1.1

If the same request had used the method GET
    GET /resource HTTP/1.1

the current representation with ETag=v1 would have been selected.

Thereforev1 is the selected representation. If the response contains
ETag header, it is a metadata about the selected representation, i.e.

Zhong Yu

Received on Wednesday, 31 October 2012 15:30:29 UTC