获取集合与Backbone.js的总和（所有型号） [英] Getting the sum of a collection (all models) with backbone.js

问题描述

我刚学骨干。我有以下

window.ServerList = Backbone.Collection.extend({

    model: Server,

    cpuTotal: function(){
        if (!this.length) return 0;
        /* 
        * NOT SURE HOW TO SUM THEM 
        * this.get('cpu') is an integer for each of the collections
        */
        return this.get('cpu');
    }

});

我是从这样的

 window.AppView = Backbone.View.extend({

     // ....

     render: function(){
         var total_cpu = ServerList.cpuTotal();
         var items = ServerList.length;

     }
 });

变量total_cpu始终是空的，但项目始终是正确的。任何想法？

The variable total_cpu is always empty but items is always correct. Any ideas ?

我知道我的收集工作，因为我有很多的项目在那里，但我需要从每个项目集合中添加了所有的CPU为页的摘要。

I know my collection is working as I have plenty of items in there, but I need to add up all the CPU's from each item in the collection for the page summary.

对于那些谁知道待办事项例如<一个href=\"http://documentcloud.github.com/backbone/docs/todos.html\">http://documentcloud.github.com/backbone/docs/todos.html我有一个非常类似的设置。

For those who know the todos example http://documentcloud.github.com/backbone/docs/todos.html I have a very similar setup.

推荐答案

下面是我所知道的最好的方式方法如下：

Here is the best way I know how:

cpuTotal: function() {
    return this.reduce(function(memo, value) { return memo + value.get("cpu") }, 0);
}

下面是解决方案的的jsfiddle。

Here is a jsFiddle of the solution.

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