Is it possible to know the target DOMWindow for an HTTPRequest?

Question

I\'m developing a firefox extension which requires me to intercept page loads by filtering out some HTTPRequests. I did that using the instructions given here. Please note t

Answer 1

You can usually do that by using nsILoadContext interface (sadly barely documented) attached to the request or its load group. Here is how you would do that:

function getWindowForRequest(request)
{
  if (request instanceof Components.interfaces.nsIRequest)
  {
    try
    {
      if (request.notificationCallbacks)
      {
        return request.notificationCallbacks
                      .getInterface(Components.interfaces.nsILoadContext)
                      .associatedWindow;
      }
    } catch(e) {}

    try
    {
      if (request.loadGroup && request.loadGroup.notificationCallbacks)
      {
        return request.loadGroup.notificationCallbacks
                      .getInterface(Components.interfaces.nsILoadContext)
                      .associatedWindow;
      }
    } catch(e) {}
  }

  return null;
}

Note that this function is expected to return null occasionally - not every HTTP request is associated with a window.