I created a custom portal login using the above reference to access the QlikView Access Point and it's working.
I noticed several things:
If I refresh the custom portal page (It's in a different tab) and if I go to my Document tab I noticed my all selections lost. But Still I'm logged in.
But If I wait till the session out and login again Selection are remaining!
What I'm doing is:
To request for a WebTicket:
/QvAJAXZfc/GetWebTicket.aspx page with a POST containing XML in the following format: