Defn of Location in 200, 301, and 302

[moved from www-talk -- specification wording should be discussed here].

Dave Kristol wrote:

>I quibble with your [Marc's] interpretation of the spec.  The actual words are
>	"For 2xx responses, the location should be the URL needed to
>	retrieve the same resource again..."
>Apparently the "should" is ambiguous.  You read it to mean that a
>server *must* send a Location header, and its value "should be the
>URL...".  I read it to mean that *if* the server sends Location, its
>value "should be the URL...".

Yes, and that is stated clearly in the section on 200.

   If the entity corresponds to a resource, the response may include a 
   Location header field giving the actual location of that specific 
   resource for later reference.

>AFAIK, servers are not required to send Location except when they send
>a 30[123] response.  In looking at the spec., though, I find that it is
>fuzzy about which headers must be sent under what circumstances.  In
>particular, the descriptions of the 30[123] response codes should
>probably make explicit reference to the Location and URI headers.

????? You mean, more explicit than [e.g., 302]

   If the new URI is a single location, its URL must be given by the 
   Location field in the response. If more than one URI exists for the 
   resource, the primary URL should be given in the Location field and 
   the other URIs given in one or more URI-header fields. The Entity-
   Body of the response should contain a short hypertext note with a 
   hyperlink to the new URI(s).

How is that not sufficient?

>In general it would be nice to be able to identify quickly which
>headers are required and which, optional.  (That's a weasily way of
>saying "Would someone else please propose such content for the spec.")

I tried several such mechanisms, none of which worked.  The spec cannot
be simpler than the protocol and still remain correct.


 ....Roy T. Fielding  Department of ICS, University of California, Irvine USA
                      Visiting Scholar, MIT/LCS + World-Wide Web Consortium
                      (fielding@w3.org)                (fielding@ics.uci.edu)

Received on Wednesday, 9 August 1995 14:23:05 UTC