[Project_owners] Getting Source Tab When Listening to http-on-modify-request

[Neil Deakin]

eric.jung at yahoo.com wrote:
> >>Actually I don't see an answer to my question...<<
>
> It would appear none are available via getInterface(), unless 
> something's wrong with my test function?
>
> function getInterfaceCheck() {
>   var x = new XMLHttpRequest(), CI=Components.interfaces;
>   x = x.QueryInterface(CI.nsIInterfaceRequestor);
>   for (i in [CI.nsIXMLHttpRequest, CI.nsIClassInfo, 
> CI.nsIJSXMLHttpRequest, CI.nsIDOMEventTarget, CI.nsISupports]) {
>     try {
>       x.getInterface(i);
>       print("got one");
>     }
>     catch(e) {}
>   }
> }
Because you want to 'for each' not 'for'

But for most of those interfaces, except for nsIClassInfo, you can just 
use instanceof:

if (x instanceof CI.nsIXMLHttpRequest) {
  // do stuff
}

Neil