title: use a shared controller to handle common html behaviours
body: <p>I'm a newbie on angularjs so I have a question for you.
  In my "standard html template" I have some html for the shopping cart summary, this html is on all the pages (like a popup to manage the cart quickly). So I was thinking to use a shared contoller to handle the common html pieces, something like:</p>
  
  <pre><code>app.controller ('SharedCtrl', function ($ brooms, cartService) {
      ...
      $ scope.cart = myBagService.get(); // get items from local store
      $scope.removeCartItem = function(key){
          myBagService.remove(key){..}; //remove stored item
          myBagService.add(item){..}; //store item
          $scope.cart = myBag.get(); //update binding items
      }
      ...
  }
  </code></pre>
  
  <p>Is this a correct way to accomplish this task?
  if yes, how I can call the above methods from other controllers ? for example on the product detail page I have to call the add method.</p>