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EmberJS 重新打开类和实例

重新打开类和实例

这只是更新类的实现,而不重新定义它。这是必要的,只有当你不想扩展内置类,但更新其实现。这可以通过使用以下方法:

  • reopen():此方法通常会将属性和方法添加到实例

  • reopenClass():方法会将属性和方法添加到

var Person = Ember.Object.extend({
   firstName: null,
   lastName:  null
});

Person.reopen({
   middleName: 'Smith'
});

var Person = Ember.Object.extend({
   firstName: null,
   lastName:  null
});

Person.reopenClass({
   createMan: function() {
      return Person.create({isMan: true})
   }
});

上面的代码描述了如何重新打开类Person,将变量名称middleName添加到实例,并使用reopenClass为Person类添加createMan函数。

例子

<!DOCTYPE html>
<html>
   <head>
      <title>Emberjs Reopening Classes and Instances</title>
      <!-- CDN's-->
      <script src="/attachements/w3c/handlebars.min.js"></script>
      <script src="/attachements/w3c/jquery-2.1.3.min.js"></script>
      <script src="/attachements/w3c/ember.min.js"></script>
      <script src="/attachements/w3c/ember-template-compiler.js"></script>
      <script src="/attachements/w3c/ember.debug.js"></script>
      <script src="/attachements/w3c/ember-data.js"></script>
   </head>
   <body>
      <script type="text/javascript">
         //reopen() method for instances
         var Person = Ember.Object.extend({
            firstName: null,
            lastName:  null,
         });

         //adding new variable to the Person class
         Person.reopen({
            middleName: 'Smith',
         });
         document.write('Middle Name: '+Person.create().get('middleName'));

        //reopenClass() method for classes
         var Person = Ember.Object.extend({
           firstName: null,
           lastName:  null,
         });
         Person.reopenClass({
          //creating new method for class Person
          createMan: function() {
             return Person.create({isMan: true})
          }
        });
        document.write('isMan: '+Person.createMan().get('isMan'));
     </script>
   </body>
</html>

输出

让我们执行以下步骤,看看上面的代码如何工作:

  • 将以上代码保存在 reopncls_inst.html 文件中

  • 在浏览器中打开此HTML文件。

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