Login onto webpage: getElementsByTagName and Windows Server 2012 R2

Im trying to logon to a web page, go to a page, modify a value, and save it.

There are two ways to do this: “$ie = New-Object -com internetexplorer.application;” OR “Invoke-WebRequest”. I perfer to do the way that is more clear to me.

Trying to do it thru “$ie = New-Object -com internetexplorer.application”, I get a error when trying $ie.Document.getElementsByName as in:

Cannot find an overload for “getElementsByTagName” and the argument count: “1”.

This only happens in Windows Server 2012 R2, not in Windows 7.

I havent played around too much with Invoke-WebRequest as Im not too sure how to do it.

I had this for now:

$initialRequest = Invoke-WebRequest -Uri ‘http://192.168.100.97/csl/login’ -SessionVariable WebSession1

form = $initialRequest.Forms[0]
$form.fields.userpwd = “mypass”
$form.fields.username = “myuser”

$loginRequest = Invoke-WebRequest -Uri (‘http://192.168.100.97/csl/login’ + $form.Action) -Method Post -Body $form.fields -WebSession $WebSession1

$tcpipRequest = Invoke-WebRequest -Uri ‘http://192.168.100.97/form/Device?act=5’ -WebSession $WebSession1

TODO: After this, I want to first test going to I need to go http://192.168.100.97/form/Device?act=5

TODO: Then I need to get the text value inside a textbox called gateway

So how do I keep going?

The IE COM object is imperfectly mapped into .NET by Interop, meaning it isn’t always reliable - as you’re seeing. And, most importantly, it doesn’t exist on most servers as it does on clients - which is WHY you’re seeing what you are.

The difficulty is that Invoke-WebRequest isn’t a web browser. It doesn’t implement JavaScript, and it doesn’t do all the magic that a browser does. If you already KNOW the form fields that you want to submit, there’s no reason to retrieve the page whatsoever. You simply have to POST a request to the web page (using Invoke-WebRequest), and include your form field values in the request header.

This is going to require quite a bit of familiarity with how the HTTP protocol works.