Can't able to read the data from app.variableMap

Hi team,

I am using the below code to read the data from variable map and it is working fine in normal browser. But, if I try to execute the same in the BitBar, I can't get the values from variable map.

var pageObj = Sys.Browser().Page("*");  //this line will get the object of current browser page, I need to get the object of the page which is in the bitbar.
var lineItemsInCartArr = pageObj.contentDocument.Script.eval("app.variableMap.productLineItem");