Ember.js有很多复选框列表

Question

我有以下两种型号:

App.Child = DS.Model.extend({
    name: DS.attr('string')
});

和:

App.Activity = DS.Model.extend({
    children: DS.hasMany('child',{async:true}),
    name: DS.attr('string')
});

我想使用复选框在hasMany关系中在现有子节点之间进行选择.

例如,我有这三个孩子:

App.Child.FIXTURES = [
  { id: 1, name: 'Brian' },
  { id: 2, name: 'Michael' },
  { id: 3, name: 'James' }
];

用户应该能够在创建或编辑活动时使用复选框,以选择要添加到hasMany关系的子项.

我创建了一个JSFiddle来说明我的问题:http://jsfiddle.net/Dd6Wh/.点击"创建新活动"以查看我正在尝试执行的操作.

基本上它与Ember.Select [...] multiple ="true"相同,但是对于复选框.

对于像Ember.js这样的事情,正确的方法是什么？

Answer 1

您可以itemController在each视图助手中使用a 来管理选择.在下面的代码中我创建了一个名为ChildController:

App.ChildController = Ember.ObjectController.extend({    
    selected: function() {
        var activity = this.get('content');
        var children = this.get('parentController.children');
        return children.contains(activity);
    }.property(),
    selectedChanged: function() {
        var activity = this.get('content');
        var children = this.get('parentController.children');
        if (this.get('selected')) {                                    
            children.pushObject(activity);            
        } else {                                    
            children.removeObject(activity);                                                    
        }        
    }.observes('selected')
});

使用itemController,您可以公开一些属性和逻辑,而无需将其直接添加到模型中.在那种情况下,selected计算属性和selectedChanged观察者.

在模板中,您可以使用绑定选择checkedBinding="selected".因为itemController代理每个模型,selected所以将使用itemcontroller 的属性,并且{{name}}绑定将查找模型的name属性:

<script type="text/x-handlebars" data-template-name="activities/new">
    <h1>Create a new activity</h1>

    {{#each childList itemController="child"}}
        <label>
            {{view Ember.Checkbox checkedBinding="selected"}}
            {{name}}
        </label><br />
    {{/each}}
    {{view Ember.TextField valueBinding="name"}}
    <button {{action create}}>Create</button>
</script>

编辑模板中的相同方法:

<script type="text/x-handlebars" data-template-name="activities/edit">
    <h1>Edit an activity</h1>

    {{#each childList itemController="child"}}
        <label>
            {{view Ember.Checkbox checkedBinding="selected"}}
            {{name}}
        </label><br />
    {{/each}}
    {{view Ember.TextField valueBinding="name"}}
    <button {{action update}}>Update</button>
</script>

这是一个小工具http://jsfiddle.net/marciojunior/8EjRk/

组件版本

模板

<script type="text/x-handlebars" data-template-name="components/checkbox-select">
    {{#each elements itemController="checkboxItem"}}
        <label>            
            {{view Ember.Checkbox checkedBinding="selected"}}
            {{label}}
        </label><br />
    {{/each}}    
</script>

使用Javascript

App.CheckboxSelectComponent = Ember.Component.extend({   
    /* The property to be used as label */
    labelPath: null,
    /* The model */
    model: null,
    /* The has many property from the model */
    propertyPath: null,
    /* All possible elements, to be selected */
    elements: null,
    elementsOfProperty: function() {
        return this.get('model.' + this.get('propertyPath'));
    }.property()
});

App.CheckboxItemController = Ember.ObjectController.extend({    
    selected: function() {        
        var activity = this.get('content');
        var children = this.get('parentController.elementsOfProperty');        
        return children.contains(activity);
    }.property(),
    label: function() {    
        return this.get('model.' + this.get('parentController.labelPath'));
    }.property(),
    selectedChanged: function() {
        var activity = this.get('content');
        var children = this.get('parentController.elementsOfProperty');
        if (this.get('selected')) {                                    
            children.pushObject(activity);            
        } else {                                    
            children.removeObject(activity);                                                    
        }        
    }.observes('selected')
});

更新小提琴http://jsfiddle.net/mgLr8/14/

我希望它有所帮助