execute a method from protractor and get the return value

Can I execute a method from protractor and get the return value of the method?

For example: I use jqxGrid widget, and the widget have a method that return the table details in json, how can I import the variable to the protractor project.

The method I want to call in the project:

var table = $("#Grid").jqxGrid('exportdata', 'json');

The test in the protractor:

it("Get table", function(){

});