javascript - 在 backbone.js 中监听集合的更改事件时，如何判断哪个模型发生了变化

Question

我在 backbone 中创建了两个集合，我想将第一个集合绑定(bind)到第二个集合的模型更改事件。

    var ProjectUserList = Backbone.Collection.extend({

        model: app.projectUser,
        url: config.base + 'api/project/project_users'

    });

    //instantiate
    app.projectUserList = new ProjectUserList();

第二个集合包含来自第一个的绑定(bind)更改事件:

    var FileList = Backbone.Collection.extend({

        initialize: function () {
            app.projectUserList.on('change', this.updateShare);
        },

        updateShare: function () {
            console.log(this);
        }
    });

我如何知道集合中的哪个模型发生了变化？

Answer 1

来自fine manual :

Catalog of Events

Here's a list of all of the built-in events that Backbone.js can fire. You're also free to trigger your own events on Models and Views as you see fit.

• [...]
• "change" (model, options) — when a model's attributes have changed.

所以 "change" 的第一个参数事件处理程序将是最初触发事件的模型。

例如，给定一个像这样的简单设置:

var M = Backbone.Model.extend({});
var C = Backbone.Collection.extend({
    model: M
});
var c = new C([
    { id: 1, s: 'where' },
    { id: 2, s: 'is' },
    { id: 3, s: 'pancakes' },
    { id: 4, s: 'house' }
]);
c.on('change', function(model, options) { /*...*/ });
c.at(​​​​​​​​​​​​​​​​​3).set('s', 'house?');​​​​​​​​​​

model "change" 的参数处理程序将是一个包装 { id: 4, ... } .

演示:http://jsfiddle.net/ambiguous/aE2XE/