每个Backbone.js + Handlebars

Question

我正在尝试将Ryan的RailsCast on Backbone.js转换为使用Handlebars并且我遇到了一个简单的问题。

我似乎无法遍历JSON数组并显示结果。我在我的Gemfile中使用这些宝石

gem 'backbone-on-rails'
gem 'handlebars_assets'

在我的index.jst.hbs中，我有以下内容：

{{entries.length}}

<ul>
    {{#each entries.models}}
        <li>{{name}}</li>
    {{/each}}
</ul>

API调用似乎正常工作，您可以在屏幕截图中的7个数字中看到。

但是，不显示每个模型的内容。这是下面的View（index.js.coffee）和JSON响应。

 class Raffler.Views.EntriesIndex extends Backbone.View
      template: JST['entries/index']

      initialize: ->
        #triggered when view gets created, listen to 'reset' event, then re-@render, pass 'this' for context binding
        @collection.on('reset', @render, this)

      render: ->
        $(@el).html(@template(entries: @collection))
        this

JSON：

[
{
"created_at":"2012-06-28T18:54:28Z",
"id":1,
"name":"Matz",
"updated_at":"2012-06-28T18:54:28Z",
"winner":null
},
{
"created_at":"2012-06-28T18:54:28Z",
"id":2,
"name":"Yehuda Katz",
"updated_at":"2012-06-28T18:54:28Z",
"winner":null
},
{
"created_at":"2012-06-28T18:54:28Z",
"id":3,
"name":"DHH",
"updated_at":"2012-06-28T18:54:28Z",
"winner":null
},
{
"created_at":"2012-06-28T18:54:28Z",
"id":4,
"name":"Jose Valim",
"updated_at":"2012-06-28T18:54:28Z",
"winner":null
},
{
"created_at":"2012-06-28T18:54:29Z",
"id":5,
"name":"Dr Nic",
"updated_at":"2012-06-28T18:54:29Z",
"winner":null
},
{
"created_at":"2012-06-28T18:54:29Z",
"id":6,
"name":"John Nunemaker",
"updated_at":"2012-06-28T18:54:29Z",
"winner":null
},
{
"created_at":"2012-06-28T18:54:29Z",
"id":7,
"name":"Aaron Patterson",
"updated_at":"2012-06-28T18:54:29Z",
"winner":null
}
]

Answer 1

您的@collection大概是Backbone.Collection。 Handlebars会将其视为某种数组，以便{{entries.length}}按预期工作，{{#each entries.models}}迭代正确的次数;但是，Handlebars不知道如何处理Backbone.Model内的@collection.models。

使用toJSON将@collection转换为原始数据，Handlebars知道如何处理简单的JavaScript数组和对象：

render: ->
    @$el.html(@template(entries: @collection.toJSON()))
    @

然后调整模板以仅查看entries而不是entries.models：

<ul>
    {{#each entries}}
        <li>{{name}}</li>
    {{/each}}
</ul>

演示：http://jsfiddle.net/ambiguous/tKna3/

Backbone的一般规则是将model.toJSON()或collection.toJSON()传递给您的模板，以便他们不必了解Backbone方法（例如get），以便您的模板不会意外地改变您的模型和集合。