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Re: HTTP Methods

From: Robert Hahn <rhahn@tenletters.com>
Date: Wed, 25 Feb 2004 09:20:49 -0500
To: www-tag@w3.org
Message-Id: <CF834CEA-679D-11D8-BD40-000A9577390A@tenletters.com>

I'm a bit late to the MGET discussion, so I'm not sure if I'm aware of 
all the thinking behind it, but based on your recent emails, Patrick, 
I'm assuming that MGET fetches all the possible representations with 
one URI call.

If that's the case, can't we simply gzip all the representations and 
send it to the client to pick and choose from?

And if my assumption is incorrect, (and I'm meant to understand that 
MGET fetches a menu of possible representations to choose from) then 
consider the following notion:

A client wants to select one of possibly many representations.  The 
client doesn't know what's available, and so sends the following URI:


The server, upon getting it, parses through the URI, finds the 
wildcard, and makes a determination on what to send back.  I can see 
two ways to go about this.

One way is inspired by the means that the server determines which 
language translation to send back to the server. I seem to recall 
seeing a weighted list of possible languages that I think is sent by 
the browser to help the server decide whether to send a page in, say, 
English or French, and if English is not available, select the next 
most weighted candidate language.  I unfortunately don't know what spec 
(or part thereof) that feature comes from, but it seems to me that it 
could be generalized to any sort of representation, not just 
representations based on language.  Since filename extensions are a 
dime a dozen, I suggest that the list of expected representations 
comprise of mime types instead of filename extensions.

The other way is to have the server send back a 'menu', have the client 
choose something off of the menu, and use that as the default for 
further transactions (perhaps by storing the menu selection as a 
cookie).  When I get some spare time, I intend to prototype this method 
on my site to see how it would work out.


On Wednesday, February 25, 2004, at 08:44  AM, Patrick Stickler wrote:

> What if the resource denoted by the URI has an RDF/XML representation
> yet you don't want the representation of the resource, you want its
> description.
> Content negotation is about selecting between representations.
> While it might be possible to make it work for differentiating
> between representations and descriptions, it precludes the ability
> to select between different encodings of a description and also
> (even if a special MIME type is used for descriptions) does not
> make it possible to ask for descriptions of descriptions as opposed
> to a representation of the description itself.
Robert Hahn,
Received on Wednesday, 25 February 2004 09:24:31 UTC

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