使用带有attr-bind的实体对象的参数调用函数

Question

我无法理解余烬模板。

所以我有这样的对象，它是分配给indexRoute型号：

App.Session = Ember.Object.extend({ 
    function_without_argument: function() { 
    return 'http://www.veryicon.com/icon/png/Flag/Rounded%20World%20Flags/Spain%20Flag.png'; 
    }.property(), 

    with_argmument: function (value){ 
    return 'http://www.veryicon.com/icon/png/Flag/Rounded%20World%20Flags/' + this.get(value) + '%20Flag.png'; 
    }.property() 
}); 

调用<img width="20" {{bind-attr src=function_without_argument}}>作品，但不带参数<img width="20" {{bind-attr src="with_argmument answer.leader"}}>。

为什么？

我做了一个小codepen例如：http://codepen.io/gurix/pen/zmdDh

Answer 1

计算属性不应该接受一个参数，而不是使用对象的属性。

例，

http://codepen.io/anon/pen/ghnsD

JS

App = Ember.Application.create(); 

App.Router.map(function() { 
    // put your routes here 
}); 

App.Session = Ember.Object.extend({ 
    targetFlag:null, 
    function_without_argument: function() { 
    return 'http://www.veryicon.com/icon/png/Flag/Rounded%20World%20Flags/Spain%20Flag.png'; 
    }.property(), 

    answer_image: function(){ 
    return 'http://www.veryicon.com/icon/png/Flag/Rounded%20World%20Flags/' + this.get("answer.leader") + '%20Flag.png'; 
    }.property() 
}); 


App.IndexRoute = Ember.Route.extend({ 
    model: function() { 
    var session = App.Session.create(); 
    session.setProperties({ 
     token: 'abc', 
     answer: { 
     leader: 'Switzerland', 
     looser: 'Argentina' 
     }}); 
    return session;} 
}); 

HBS

<script type="text/x-handlebars"> 
    <h2>Welcome to Ember.js</h2> 

    {{outlet}} 
</script> 

<script type="text/x-handlebars" data-template-name="index"> 

    without argument: <img {{bind-attr src=function_without_argument}}> 

    {{answer.leader}} becomes the image ... 

    <img {{bind-attr src=answer_image}} > 



</script>