Passing custom parameters to a web resource in v9

I'm running Dynamics 365 v9, and can't pass parameters to a web resource embedded in a form.  I've tried the methods shown in these links:

http://butenko.pro/2015/03/01/howto-htmljs-webresources/

https://msdn.microsoft.com/en-us/library/gg327945.aspx

I have added "test=testValue1" to the custom parameter box in the web resource, but, when I call "GetGlobalContext().getQueryStringParameters()" or "location.search()", my result contains only the appId parameter from the parent windows URL.  Am I misunderstanding something?