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Re: Web browsers, HTTP and transcoding

From: Jo Rabin <jrabin@mtld.mobi>
Date: Fri, 17 Oct 2008 13:35:37 +0100
Message-ID: <48F88699.60600@mtld.mobi>
To: Tom Hume <Tom.Hume@futureplatforms.com>
CC: Francois Daoust <fd@w3.org>, Rotan Hanrahan <rotan.hanrahan@mobileaware.com>, public-bpwg-ct <public-bpwg-ct@w3.org>

Coming in the middle of this thread:

The third bullet of 4.3.6 [1] says that you should look at the content 
type. We've examined and re-examined specifying what a CT proxy should 
look for and decided not to include examples. No reason why we shouldn't 
re-re-examine!

Also, the current 4.2.2 [2] specifies that the server must send a 
no-transform if one is received, and this is specifically to allow XHR 
requests with no-transform to achieve what they expected, which is get 
an untransformed response. However, we have received objections to 
stating this as it is said to be inventing a new protocol or profiling HTTP.

Jo

[1] 
http://www.w3.org/TR/2008/WD-ct-guidelines-20080801/#sec-proxy-decision-to-transform
[2] 
http://www.w3.org/TR/2008/WD-ct-guidelines-20080801/#sec-cache-control-no-transform

On 17/10/2008 09:54, Tom Hume wrote:
> 
> Has an approach of not transcoding content types explicitly used for 
> data rather than data+presentation (e.g. text/xml) been considered?
> 
> On 17 Oct 2008, at 08:51, Francois Daoust wrote:
> 
>> In the end, Rotan is right, it is just impossible to identify HTTP 
>> messages intended for "web browsing" using a deterministic algorithm. 
>> Some "magic" is involved, and it simply cannot work in 100% of all 
>> cases. Adding a "Cache-Control: no-transform" directive in an XHR call 
>> (fairly simple to do, provided you know you have to do it, that is) is 
>> the only way to go to make sure CT-proxies would leave the message 
>> untouched.
> 
> -- 
> Future Platforms Ltd
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Received on Friday, 17 October 2008 12:36:38 GMT

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