Monday, August 29, 2011

some thoughts about Watin, windows 7, slow performance, upload dialogs & exceptions caused by UAC issues

When trying to figure out which to use between the two most popular web automation tools Watin & Selenium, I chose Watin as it was simple to start with at the time (a few years back) and worked great with C# and visual studio on windows.

Then my automation needs grew, and I needed to upload files into forms and with the new versions of IE I found out that I will have to use Firefox as IE has a permission/security problem automating the upload dialogs.
Firefox requires the jssh addon for receiving automation commands, which was OK at the time.

Jssh addon exists for Firefox up to version 3.6, but with the latest version race Mozilla took, Firefox is now up to version 6 and there is no compatible jssh plugin for it.

So, what options do we have ? it seems there are two :
1) remove your FF 6 and install the latest 3.6.X
2) use a VM with FF 3.6.X installed on it

There is another option:
3) Installing a portable FF version alongside the system FF 6 (you will still need to add the jssh add on to the portable version but that is not a problem).

The problem with this is that you will need to use the FireFox.PathToExe method and set it to the path of the portable firefox version (including the file name). But your problems won't end here, you will need to recompile Watin from the sources and do some changes too.

After doing all the above for solution #3, I still had exceptions from Watin, so I went back to option #1 (even though, as you will soon see below I could have stayed with option 3 and used the same fix for the exceptions too)

So back to option #1.
Still got an exception, and now in Process.HasExited inside the Watin library.
Didn't quit, compiled watin in debug and searched the internet - turns out Process.HasExited throws an exception when it is accessed from a non-privileged process (this pertains to Vista and Windows 7 which have the UAC feature on). Thanks Microsoft for not giving me just a 'process has no privilege' exception with a pointer to UAC :/ ) instead you get an Access Denied ...

So you need to run the process with 'run as an administrator' - then it worked !

But wait, I want to run it in visual studio in debug, but that doesn't work because it doesn't run it as administrator..., so you need to run visual studio itself has 'run as administrator' to causs all debug sessions to be run with the same privileges.

Everything seems to work now, except for my application hanging for a lot of time in different locations so that I see as if the Watin flow is very slow and sometimes seems to stop for several minutes before selecting radio buttons and clicking buttons onthe web page. So i ran it in debug and just pressed 'pause' in visual studio each time I saw it hang and not progress with running the web automation.

To my surprise I found out the problem with the watin program running very slow and sometimes just hanging was in my code when i called a logging function that updated a RichTextBox with new text that says what phase has been done between watin operations:

private void LogPrint(string str)
{
    logTextBox.AppendText(logTextBox.Text + str + "\n");
}

I have no idea why this happens (some race condition between wating and GUI threads  with waitformultipleobjects() maybe ??? i don't know, i am just happy that after commenting it out the logging everything worked fast and good !)

Hope this helps some people out there - Watin is a great web automation tool !

1 comment:

  1. Nice link to comparison between web recording APIs (selenium/ Watin / VS2010).

    http://blog.gfader.com/2010/02/smack-down-watin-vs-selenium-vs-vs2010.html

    ReplyDelete

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