demoDirective.js

function DemoDirective(){
     return {
       restrict: 'E',
       scope: {
         stringBind: '@',
         objectBind: '=',
         functionBind: '&'
       },
       template: [
         '<p>Hello, {{vm.stringBind}}! Please order donuts:</p>',   
         '<p>Quantity: <input ng-model="vm.objectBind"></p>',
         '<p><button ng-click="vm.functionBind()">Order Donuts!</button>'
       ].join(''),
       controller: 'DemoDirectiveController',
       controllerAs: 'vm',
       bindToController: true
     };
  }