Selenium IE9 WaitForPageToLoad Fix

Posted on Friday, August 26, 2011

There appears to be an issue in Selenium that causes WaitForPageToLoad to act improperly in IE9.

To resolve the issue copy the following code into a file called "user-extensions.js":

LOG.info("Extension included");

IEBrowserBot.prototype._windowClosed = function (win) {
LOG.debug("Using overridden window closed");
try {
 var c = win.closed;
 // frame windows claim to be non-closed when their parents are closed
 // but you can't access their document objects in that case
 if (!c) {
   try {
     win.document;
   } catch (de) {
     if (de.message == "Permission denied") {
       // the window is probably unloading, which means it's probably not closed yet
       return false;
     }
     else if (/^Access is denied/.test(de.message)) {
       // rare variation on "Permission denied"?
       LOG.debug("IEBrowserBot.windowClosed: got " + de.message + " (this.pageUnloading=" + this.pageUnloading + "); assuming window is unloading, probably not closed yet");
       return false;
     } else {
       // this is probably one of those frame window situations
       LOG.debug("IEBrowserBot.windowClosed: couldn't read win.document, assume closed: " + de.message + " (this.pageUnloading=" + this.pageUnloading + ")");
       return false;
     }
   }
 }
 if (c == null) {
   LOG.debug("IEBrowserBot.windowClosed: win.closed was null, assuming closed");
   return true;
 }
 return c;
} catch (e) {
 LOG.debug("IEBrowserBot._windowClosed: Got an exception trying to read win.closed; we'll have to take a guess!");

if (browserVersion.isHTA) {
   if (e.message == "Permission denied") {
     // the window is probably unloading, which means it's not closed yet
     return false;
   } else {
     // there's a good chance that we've lost contact with the window object if it is closed
     return true;
   }
 } else {
   // the window is probably unloading, which means it's not closed yet
   return false;
 }
}
};

Reference that file when you start the Selenium server using the "-userExtensions" option:


java -jar selenium-server-standalone-2.4.0.jar -userExtensions user-extensions.js

Now for the explanation...

I noticed that when I experienced the WaitForPageToLoad timeout, the browser logs showed an unusual error message coming from IEBrowserBot.windowclosed:

debug(1314123427103): _isSamePage: sameLoc: true
debug(1314123427103): _isSamePage: sameHref: true
debug(1314123427103): _isSamePage: markedLoc: true
debug(1314123427824): replaced getReadyState used
debug(1314123427824): pageUnloading = true!!!!
debug(1314123427824): getReadyState returning loading
debug(1314123427824): pollForLoad continue (selenium1314123422376): undefined
debug(1314123427824): runScheduledPollers DONE
debug(1314123427843): runScheduledPollers
debug(1314123427843): IEBrowserBot.pollForLoad: selenium1314123422376
debug(1314123427843): pollForLoad original (selenium1314123422376): http://localhost:8000/weblo/Gfe.aspx
debug(1314123427899): IEBrowserBot.windowClosed: couldn't read win.document, assume closed:  (this.pageUnloading=true)
debug(1314123427899): pollForLoad WINDOW CLOSED (selenium1314123422376)
debug(1314123427899): runScheduledPollers DONE
debug(1314123427900): runScheduledPollers
debug(1314123427900): runScheduledPollers DONE
debug(1314123427919): runScheduledPollers
debug(1314123427919): runScheduledPollers DONE

Looking at browser-bot.js, I noticed that the condition with the logged error "couldn't read win.document, assume closed" is the only one that returns true:

I changed that to return false and included the entire function as a user extension, thus overwriting the original:

Since then, I have run over a thousand tests (on IE9) and not one has faltered because of WaitForPageToLoad.

Labels: IE9, Internet Explorer 9, page load, pageload, Selenium, Wait for page to load, WaitForPageToLoad

# posted by Greg @ 8/26/2011 08:13:00 PM

Comments:

Thanks!

You just saved me a boatload of debugging, and our selenium test suite execution time dropped to about half on IE9.

# posted by

Mikko Koponen : September 6, 2011 at 4:30 AM

No problem! Glad I could help.

# posted by

Greg : October 8, 2011 at 8:12 PM

If it is acceptable to customize the client driver, here is the Python implementation for your refernece:

def open(self):
timeout = self.get_eval('this.defaultTimeout')
self.set_timeout(0)
self.do_command("open", [url,ignoreResponseCode])
self.set_timeout(timeout)
self.wait_for_page_to_load(timeout)

def wait_for_page_to_load(self,timeout):
# self.do_command("waitForPageToLoad", [timeout,])
import time
end = time.time() + int(float(timeout) / 1000)
while time.time() < end:
if self.get_eval('window.document.readyState') == 'complete': return
time.sleep(2)
raise Exception('Time out after %sms' % timeout)

I just use DOM attribute `document.readyState` to determine if the page is fully loaded.

http://imsardine.simplbug.com/note/selenium/rc/ie-onload-timeout_EN.html (IE 9+ intermittently throws a timeout error even the page is fully loaded), for more details.

# posted by

Jeremy / 傑洛米 : December 13, 2012 at 2:56 AM

Nice fix! Thank you.

# posted by

Anonymous : February 21, 2013 at 1:51 PM

This is straight up awesome and saved me tons of time. Thanks so much!

# posted by

Dave : March 7, 2013 at 1:40 PM

Thank Jeremy alot! The solution (customize the client driver) works fine :)

# posted by

Unknown : November 19, 2013 at 1:48 AM

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