Powershell UI Automation within a webbrowser control - powershell

Question

Ok so I recently learned how to execute UI automation using the $ie = new-object -com "internetexplorer.application" command. This works pretty good for a task I am attempting to automate on an ASPX web app...until I ran into a modal popup which freezes my script. From what I have read online, I may want to bypass this by running this same process on a form, using a forms.webbrowser control.Sample Follows
[Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms") | out-null
[Reflection.Assembly]::LoadWithPartialName("System.Drawing")
$form = New-Object Windows.Forms.Form
$form.text = "My Form"
$form.size = New-Object Drawing.size #(700,600)
$web = New-object System.Windows.Forms.webbrowser
$web.location = New-object System.Drawing.Point(3,3)
$web.minimumsize = new-object System.Drawing.Size(20,20)
$web.size = New-object System.Drawing.size(780,530)
$web.navigate("http://myASPXsite.com")
$form.Controls.Add($web)
$form.showdialog()
$doc = $web.document
$doc.getElementbyID('txtUserName').value = "myUser"
The point is that the ability to reference and invoke html elements doesn't work through this method. I can navigate to the webpage but nothing more. Could it be that the webbrowser control doesn't have the same functionality as the internetexplorer object. This is the code I would use with the other method.
$ie = new-object -com "internetexplorer.application"
$ie.navigate("http://www.MyASPXsite.com")
While ($ie.readystate -ne 4) {start-sleep -m 100}
$doc = $ie.document
$doc.getelementbyid('txtUserName').value = "myUser"
Any ideas on my situation? Am I even on the right track to handle the modal dialogs?

Answer 1

Your problem is $form.showdialog(). The script will hold up in this point until you close the form. You have to add an event handler to the form's Shown event something like this:
$form.Add_Shown({
$doc = $web.document;
$doc.getElementbyID('txtUserName').value = "myUser";
});
Then it should work

Answer 2

Just to get the Selenium suggestion out of the way before discussing PowerShell/UIA: I'd investigate using Selenium for this sort of web automation work, since it's awesome! I believe it has built-in support for handling modal dialogs.
Otherwise, if you must stay with manipulating the IE automation interface via PowerShell, I'd explore using the MS UI Automation API to deal with your modal dialog.
You can use UIA directly without any wrapper libraries, but I'd suggest using one of the existing PowerShell wrappers like WASP or the newer UIA PS extensions:
http://wasp.codeplex.com/
http://uiautomation.codeplex.com/
One approach is to write a few lines of UIA code to dismiss the modal dialog, and make sure it works in isolation (i.e., manually bring up the modal dialog, and execute just the code that should dismiss it).
Then, run the UIA code from your existing PowerShell script that drives IE. You could put the dialog handling code in a separate file and launch it via your main program.
Putting the UIA code in a separate file is a handy hack to work around a big browser automation gotcha you may be running into - it's likely whatever you're doing in code that brings up the modal dialog blocks execution of your script until the dialog is dismissed. So you must make sure your dialog-handling code is running in a separate process or thread that's launched before you cause the modal dialog to appear.