Backbone.js的获取问题（不能立刻刷新数据） [英] Backbone.js fetch problem (can't refresh data immediately)

问题描述

我有这样的code：

var MyModel = Backbone.Model.extend();

var MyCollection = Backbone.Collection.extend({
    url: '/url/',
    model: MyModel
});
var coll = new MyCollection();

URL是正确的，并返回正确的JSON。但是，如果我尝试使用下一个code：

The url is correct and returns correct json. But if I try to use the next code:

$('#fetch').click(function(){
    coll.fetch();
    console.log(coll.toJSON());
});

• 它显示我的数据只有第二次点击后（HTTP响应在Firebug后的第一个我看到）。似乎数据没有及时刷新。



如果我把每个语句在不同情况下它的工作原理是正确的。但我需要立即知道采集的长度。如何做到这一点？

If I put each statement in different event it works correct. But I need to know the length of collection immediately. How to do this?

推荐答案

请记住，取是对服务器的异步调用。为了使您的code的工作如你所料，创建一个成功函数 Backbone.Collection 可一旦调用从服务器刷新其内容：

Keep in mind that fetch is an asynchronous call to the server. To make your code work as you expected, create a success function that Backbone.Collection can call once it refreshes its contents from the server:

$('#fetch').click(function(){
    coll.fetch({
        succcess: function() {
            console.log(coll.toJSON());
        }
    });    
});

显然，你的应用程序并不需要真的叫的console.log 这样一个更真实的例子会用骨干事件这样的绑定：

Obviously you app doesn't need to really call console.log so a more real world example would use backbone's event binding like this:

coll.bind('refresh', someFunction);
coll.fetch();

通过这种方法，骨干将调用集合时刷新 someFunction 。这是非常有用的尤其是当 someFunction 是渲染您要到您的收藏绑定该视图的功能。

With this approach, backbone will call someFunction when the collection refreshes. This is really useful especially when someFunction is the render function of a view to which you want to bind your collection.

coll.bind('refresh', yourView.render);
coll.fetch();

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