Rating in angularjs

rating.js

angular.module('plunker', [])

  .directive('rating', function() {
    return {
      scope: {
        rate: '=',
        onUpdate: '&'
      },
      templateUrl: 'rating.html',
      link: function(scope, element, attrs) {
        scope.range = [1,2,3,4,5];
        
        scope.update = function(value) {
          scope.rate = value;
          if (scope.onUpdate) {
            scope.onUpdate({value: value});
          }
        };
      }
    };
  })

  .controller('MainCtrl', function($scope) {
    $scope.rate = 2;
    
    $scope.onUpdate = function(value) {
      console.log('here');
      $scope.customRate = value / 5;
    };
  });