title: How can I call a Objective-c method in a BackBonejs method
body: <p><strong>hello</strong> ,I ran into a question.I have a phoneGap and Backbone Xcode project. And the navigation is not html but UInavigationBar .when the Backbonejs view happens to change ,I want to change the navigationBar's navigationBarButtonItem. All the logic is writter in Backbone's js file .  such as the routers an a main method .sorry about post a Pic cause i got a misformatted code error.
  <img src="https://i.stack.imgur.com/YxrjY.png" alt="enter image description here">
  when I change to main page . I also want the UInavigationBar to Show a Button on the left. How should I solve this? </p>