[Javascript] Show a progress bar while waiting for a download to begin?

[Nick Fitzsimons]

Scott Reynen wrote:
> On Jun 9, 2006, at 11:04 AM, Nick Fitzsimons wrote:
>> Certainly, no browser is going to know what to do with a response with 
>> two status lines, as it's a breach of the standard.
> 
> Right, but I'm not sure it's a breach of the standard to send a redirect 
> 302 along with content.  Browsers aren't required to understand every 
> status code, only the first digit.  So a 302 can be interpreted as a 
> 300, and a 300 says:
> 
> "user agents MAY use the Location field value for automatic redirection"

Good point, but under 302, the HTTP 1.1 RFC states:

"Unless the request method was HEAD, the entity of the response SHOULD 
contain a short hypertext note with a hyperlink to the new URI(s)."

So strictly speaking, returning content in a 302 response other than a 
link to the target of the redirect is wrong-ish (it's a SHOULD rather 
than a MUST). I'd guess that browsers which implement HTTP 1.1 ignore 
the content of the response on the grounds that they know how to react 
to the 302. Just a guess, and not something I'm going to test 
extensively at 17:45 on a Friday :-)

Regards,

Nick.
-- 
Nick Fitzsimons
http://www.nickfitz.co.uk/