Ember.js hasMany 作为复选框列表 [英] Ember.js hasMany as list of checkboxes

问题描述

我有以下两种型号:

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

还有:

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

对于 hasMany 关系，我想使用复选框在现有子项之间进行选择.

I want to use checkboxes to choose between the existing children, for the hasMany relation.

例如，我有这三个孩子:

For example, I have these three children:

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来选择要添加到 hasMany 关系的孩子.

The user should be able to use checkboxes, while creating or editing an activity, for choosing which children, to add to the hasMany relation.

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"以查看我正在尝试做什么.

I've created a JSFiddle to illustrate my question: http://jsfiddle.net/Dd6Wh/. Click 'Create a new activity' to see what I'm trying to do.

基本上与 Ember.Select [ ... ] multiple="true" 相同，但用于复选框.

Basically it's the same as Ember.Select [ ... ] multiple="true", but for checkboxes.

使用 Ember.js 处理此类问题的正确方法是什么?

What's the correct approach for something like this with Ember.js?

推荐答案

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

You can use an itemController in your each view helper to manage the selection. In the code below I created one called 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您的模型中.在这种情况下，selected 计算属性和 selectedChanged 观察者.

With a itemController you can expose some properties and logics, without add it directlly to your models. In that case the selected computed property and the selectedChanged observer.

在您的模板中，您可以使用 checkedBinding="selected" 绑定选择.因为itemController代理每个模型，所以会用到itemcontroller的selected属性，{{name}}绑定，会查找模型的name属性:

In your template, you can bind the selection using checkedBinding="selected". Because the itemController proxy each model, the selected property of the itemcontroller will be used, and the {{name}} binding, will lookup the name property of the model:

<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:

The same aproach in edit template:

<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>

这是一个处理这个工作 http://jsfiddle.net/marciojunior/8EjRk/

This is a fiddle with this working 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>

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/

希望能帮到你

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