Re: Yadis section 6.2.5

Thanks for the comments.

In the current draft, which the three reviewers have, the note in 6.2.5
has been removed.

I'll put text in the Implementor's Guide based on these
comments.


>>>  Remember everyone: it's a wiki.  Text for the
Overview and Implementor's Guide are welcome at:

   

http://yadis.org/wiki/Main_Page#YADIS_Overview

Cordially, Joaquin   



> Drummond wrote:
> +1 to Martin's clarification, i.e., it would be better to say that a
> conformant implementation MUST accept both a GET with an Accept:
> application/xrds+xml request-header and a GET without it, and then
> specify
> the response in each case.


> Martin wrote:
>
> Section 6.2.5 of the spec has the following note:
>     The response to the initial request MUST comply with
> the HTTP
>     protocol; therefore, if the request is a GET and does
> not include
>     an Accept: application/xrds+xml request-header, the
> response MUST be
>     of type 1 or 2. This is REQUIRED because the Relying
> Party MAY omit
>     the Accept and so might only look for the
> X-YADIS-Location.
>
> I was with this until the last sentence. My reading of this suggests
> that all identity URLs must support the indirection case even if
> they
> support the content negotiation case. This seems a little crazy.
> This
> essentially gives identity URL maintainers two choices:
>
> * Support just the indirection case.
> * Support the indirection case and the content negotiation case.
>
> Out of those, I'd probably pick the first one since it's easier to
> only
> support one case.
>
> I think it's more appropriate to say that YADIS relying parties MUST
> send application/xrds+xml in the Accept header with a suitable
> quality
> value. It's much better to place this "burden" in the relying
> party
> since most people will be using pre-rolled libraries for relying
> parties
> and there is no disadvantage to supporting the content negotiation
> case.
>
> ------------------------------------------------
>
> As for the rest of that note, the correct way to respond when you
> have
> no document that matches a type in the Accept header is with the
> response code "406 Not Acceptable", so if there's going to be
> language
> in there about complying with the HTTP protocol there should also be
> some words about this, presumably saying that when a 406 response is
> recieved the relying party should still look for the
> X-YADIS-Location
> header and, if the Content-type is text/html, look for the meta
> tag.
>
> Note that Apache's content negotiation module will, in its default
> configuration, respond with 406 Not Acceptable as per the spec, so
> this
> case is not unlikely to arise. Of course, in the case where Apache's
> content negotation module is in play, there's unlikely to be an
> X-YADIS-Location header.