Using angular isolated scopes as event emitters

foo.js

someModule.service('something', function($rootScope) {
  var emitter = $rootScope.$new(true);
  
  var data = whateverStuffHere;
  
  return {
    onDataUpdated: function(callback) {
      //by returning the result from $on, we get
      //the ability to remove event listeners easily
      return emitter.$on('update', callback);
    },
    
    getData: function() {
      //angular.copy is used so the data remains immutable
      //and other code can't accidentally interfere/mess up the data
      return angular.copy(data);
    },
    
    doSomethingThatUpdatesData: function() {
      //fetch data or somethingn,
      //you can trigger the listeners with..
      emitter.$emit('update');
    }
  };
});