[6552] in www-talk@info.cern.ch

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Re: An MGET proposal for HTTP

daemon@ATHENA.MIT.EDU (Chris Lilley, Computer Graphics Un)
Thu Nov 3 11:28:11 1994

Date: Thu, 3 Nov 1994 17:26:03 +0100
Errors-To: listmaster@www0.cern.ch
Reply-To: lilley@v5.cgu.mcc.ac.uk
From: lilley@v5.cgu.mcc.ac.uk (Chris Lilley, Computer Graphics Unit)
To: Multiple recipients of list <www-talk@www0.cern.ch>

Marc VanHeyningen wrote:

> Chris Lilley wrote:

>> But at the moment (re the other current thread about the online 
>> newspaper) if a client asks for newspaper.html with accept text/html 
>> and image/gif, sending a big gif of the page is not actually wrong. 
>> Undesirable, but it conforms with what the client said it would 
>> accept.

> This is a function of content-type negotiation; it is generally
> not possible to losslessly convert HTML to GIF.  

Agreed. I hoped that was obvious. I deliberately picked an example of 
an undesirable (and curently topical) conversion which, currently, the 
clients seem to be saying they would accept.

> But, yes, the spec 
> allows the server to decide, based on the information given to it by 
> the client, whatever content-type it considers most appropriate. 

I was arguing for putting information into the link that aided this 
process, so the client could give it better information to perform this 
content type negotiation than simply all possible things the client 
could ever accept; such as, what it might like for the current request. 

For example, a link could be tagged as belonging to a class of 
documents that are text searchable. So the client might send an Accept 
of text/html, text/plain, application/x-pdf and anything else that the 
users' mailcap indicates that has contiguous searchable text strings in 
it. image/gif, for example, would not fall into that category, neither 
would, say, application/postscript.

> That's the point.

Sure

> Are you saying the spec should prohibit this?

No. I am saying that the process should be made easier so it actually 
gets used. In particular, I would like, for example, HTML 3 browsers to 
be able to say they can accept html 3. I would like to reduce the risk 
of clearly undesirable conversions such as the example I gave.

--
Chris

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