Following HTTP Redirects (302)

[mattbennett]

Hi all,

I'm trying to figure out how to recognize when an HTTP redirect comes back from an Ajax request. Here is my submission code:

Ext.Ajax.request({
	url: base.url+'/export/foo',
	method:'GET',
	success:function(response) {
		console.log(response)
	}, 
	failure:function(response) {
		debug.popup(response.responseText);	//show the server response in a dialog
	}
})

On the serverside, a request to "whatever.com/export/foo'" generates a file and then returns an HTTP redirect to that file. Without Ajax, the browser follows the redirect and gives me an "open/save" dialog as you'd expect.

With Ajax, I was expecting the success function above to output an object with status=302 and a redirect URL which I could push to location.href. Actually what I get in the console is "Object tId=8 status=200 statusText=OK". Firebug also shows me that the browser does honor the redirect and actually downloads the file, but I get no "open/save" dialog.

What's the correct way of dealing with this situation? I really want my serverside code to remain the same for both Ajax and non-Ajax operation.

Many thanks,
Matt.

[halkon_polako]

If you have in the console a status=200, is because the response from the server had been a http-200.

A response with http-302 is a failure.
Ext.Ajax only call success callback on http status >=200 and <300.

[mattbennett]

Hi Halkon,

Thanks for your reply. From your input, my guess is that the 200 response I'm seeing in the success function is generated *after* the redirect (i.e. the browser is following the 302, downloading the file successfully and reporting a 200 status). This also explains why FireBug crashes when I try to examine the response object - the file it's downloading is ~5MB.

So, I guess that changes my question slightly: is there any way to intercept the 302 redirect and act on it? Obviously I don't want to be downloading the file via Ajax; instead, I should capture the redirect URL and push it to location.href to download the file normally.

Thanks,
Matt.

[halkon_polako]

You can try the hendricd's extension ext-basex.js (http://extjs.com/forum/showthread.php?t=21681) where you can intercept http status codes and assign a function to them...

But...are you sure that the browser is catching the 302-redirect and then 'redirecting' to the new location? Have you seen the 302 code?... maybe you are receiving directly the file without a redirect...

[mattbennett]

Thanks Halkon,

I'll give ext-basex a whirl - looks like it'll do everything I need.

Yes, upon closer inspection the browser definitely sees the 302; the Net tab on FireBug shows this:

23 (302)
http://whatever.com/export/foo?_dc=1206382633661
whatever.com	
0 b
	
47ms
foo.zip
whatever.com/media/generated/foo.zip
whatever.com
4.76 MB

Thanks for the excellent responses. Hopefully this thread will explain the behavior of 300 responses for some other folks too.

Matt.

[coderobo]

I was tempted by this thread to look at using basex for trapping redirect. Unfortunately basex can't handle 302 as the browser preempts it. See posts in another thread http://extjs.com/forum/showthread.php?t=21681&page=11

Bottom line - redirects considered harmful with ExtJS and other AJAX frameworks.

[lohithabc]

I had the same problem the issue is the propety set with module section of the web.config
runAllManagedModulesForAllRequests="true"
remove this and it should work