Laurens Holst wrote:
Julian Reschke schreef:
Sorry, was reading one thing, but thinking about something else.
Thinking of it, could you please add a clarification that setting to
an empty string is legal, and MUST NOT be ignored? I recall that
Microsoft's original XHR (ActiveX) implementation got that wrong, not
setting the header at all.
When invoking request.setRequestHeader('Accept', ''):
Laurens, thanks a *lot* for testing this.
- Firefox 3b5 removes the Accept header
Ouch. Has this been raised as a bug yet?
- Internet Explorer 8 (in IE7 mode) sends Accept: */*
Ouch. Has this been raised as a bug yet?
- Safari 3.1.1 sends Accept:
Good.
- Opera 9.24 sends Accept: text/html, application/xml;q=0.9,
application/xhtml+xml, image/png, image/jpeg, image/gif,
image/x-xbitmap, */*;q=0.1
Not good.
When invoking request.setRequestHeader('Accept', null):
- Firefox 3b5 removes the Accept header
Makes sense, but isn't what XHR1 requires.
- Internet Explorer 8 (in IE7 mode) sends Accept: null
You really mean the four characters n-u-l-l? Ouch,
- Safari 3.1.1 sends Accept: null
- Opera 9.24 sends Accept: text/html, application/xml;q=0.9,
application/xhtml+xml, image/png, image/jpeg, image/gif,
image/x-xbitmap, */*;q=0.1
I notice that none of the browsers does what XHR1 requires, but at least
*one* (FF) does something useful.
So it is clear that here, too, browsers are in great disagreement. I am
not sure what the correct approach here is, though '' meaning setting
“Accept” and null meaning removal of the header sounds sensible.
Note by the way that Opera always prepends the set Accept header to its
default value, resulting in e.g. Accept: */*, text/html,
application/xml;q=0.9, application/xhtml+xml, image/png, image/jpeg,
image/gif, image/x-xbitmap, */*;q=0.1 when invoking
request.setRequestHeader('Accept', null);
That should be considered a bug.
I can’t believe how horribly broken this all is. No wonder few people
depend on this header. Fortunately, as a result it can also be fixed
without breaking much.
I’ve also posted these results at http://www.grauw.nl/blog/entry/470 ,
the page source contains a test case.
BR, Julian
