Re: [XHR2] Upload events flag

On Thu, 12 Mar 2009 15:28:51 +0100, Alexey Proskuryakov <>  
> What is the meaning of upload events flag in XMLHttpRequest 2?

It forces a preflight request when event listeners are registered.

> Its definition is that it "is used in the send() algorithm to determine  
> whether upload progress events will be dispatched for non same origin  
> requests." However, it is only set by send, and is only used for passing  
> in cross-origin request algorithm as force preflight flag.


> If the current text accurately describes how this flag is supposed to  
> work, I'd suggest an editorial change that will remove it, and say want  
> to pass to CORS directly. However, my understanding is that it might in  
> fact need to prevent dispatching progress events even in case a listener  
> gets added after invoking CORS. Was that the intention?

It is not needed for that case because events will only be dispatched if a  
preflight request was made.

Anne van Kesteren

Received on Monday, 16 March 2009 11:50:02 UTC