[whatwg] XMLHttpRequest

Joe Gregorio joe.gregorio at gmail.com
Wed Dec 1 20:07:47 PST 2004

On Fri, 26 Nov 2004 02:52:28 +0000 (UTC), Ian Hickson <ian at hixie.ch> wrote:
> I have attempted to answer this question at:
>    http://whatwg.org/specs/web-apps/current-work/#setrequestheader
> Let me know if the new text is satisfactory. (In short, it depends based
> on which header the author tries to override.)

This looks good. I do have three observations:

1.) One of the things that doesn't seem clear is the 'everything is
append by comma rule'. I think the intention is that the rule only
applies to the headers that aren't covered in the exceptions section,
but I can't be sure from the wording.

For example, if User-Agent: is allowed to be appended to, shouldn't
that be an exception to the 'everything is appended with a comma'
rule, given the formatting rules for the User-Agent header require it
to be space separated. Same idea for Cookie headers using ';' as a

2.) Does the fourth bullet, with it's restriction on the
If-Modified-Since, If-None-Match, If-Range, and Range headers, only
apply if the method is 'GET" or 'HEAD'? I would hope they could be
overridden if the method were PUT, POST, DELETE, etc.

3.) What is the reasoning for restricting the Range header even in the
case of a GET/HEAD? I am in particular thinking of cases where the
units of Range are not 'bytes' but some custom value.


Joe Gregorio        http://bitworking.org

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