OS handles JS constraints and GPD constraints differently?

Question

There is some question about the way OS handles JS constraints and GPD constraints.

We implemented Javascript constraints for the v4 driver. When the print settings that constrain in the javascript are selected in Advanced Settings on Metro UI, the Back button does not work so we think the JS constraints are working. We also have constraints defined in GPD. For example, Photo paper has to get Photo quality (720dpi) selected. when trying to print from Metro UI, the Back button works and quality is fixed automatically to Photo (720dpi).

Is it by design that OS handles differently between JS constraints and GPD constraints?.

Also, I found the similar question previously posted but the thread ended with the last comment it was a known issue. http://social.msdn.microsoft.com/Forums/sa/tailoringappsfordevices/thread/e30981cb-8ba9-402c-b9fb-0f817a849a6e

Although we understand more complex constraints that can not be handled in GPD should be implemented in a JS constraints file, we are a bit confused by this behaviors and if JS constraints are designed to work with Windows Device Apps while GPD constraints to work well only with Desktop Standard Preferences UI.

Thanks in advance for your help.

Answer 1

Seatie,

I am looking into this for you.

Best Wishes - Eric 

Answer 2

Seatie,

There are differences.  They are listed in the V4 printer driver whitepaper:  http://msdn.microsoft.com/en-us/library/windows/hardware/br259124.aspx .  It may also take a little testing to see what they are.

Best Wishes - Eric

Answer 3

Thanks for your reply, Eric. The white paper does not seem to have the information that we had hoped there would be, but we will continue to look into the actual behaviors to figure out what is missing in our JS.