Backbone 查看监听模型，更改或重置时不触发？

Question

我正在使用模型从使用 POST 的服务中获取位置数据。但是，当它最终收到响应时，我正在努力让视图收听该模型。

请注意，我已经覆盖了一些模型方法以适应我正在使用的服务。

型号代码

        define([
        'underscore',
        'backbone',
    ], function (_, Backbone)
    {
        'use strict';

        //model class declaration
        var LocationsModel = Backbone.Model.extend({

            locations: null, //this attribute stores the json response


            //url for http post to get location data
            url: '/testserver/getLocationData',

            /**
                 @name constructor
                 @method initialise
            **/
            initialize: function ()
            {
                console.log("Location Model - Initialize");
                this.fetchLocationData();  
            },

            /**
                @name fetchLocationData
                @method fetchLocationData
                @summary retrieves bulding/location data from service, overriden fetch function to use POST
            **/
            fetchLocationData: function ()
            {
                console.log("Location Model - Fetching Building/Location data from EAS");

                this.fetch({
                    data: JSON.stringify({ "lastRefreshedDateTime": "2015-04-01T08:18:06.000+00:00", "uid": "" }),  //refactor this - string literals which are static currently
                    type: "POST",
                    contentType: "application/json",
                    async : false, //this is bad but it is the only way I can get it to work

 at the moment
                reset: true //tried adding reset parameter but no luck
            });
        },

        /**
           @name parse
           @method parse
           @summary parse is a method inside backbone that can be overridden, in this override we set a model attribute to the JSOn response
       **/
        parse: function (response, xhr)
        {
            console.log("Location Model - Parsing response from EAS");
            this.attributes = { "true": true }; //tried adding an attribute value to trigger "change:true"
            this.locations = response;
            //do other stuff
        },


    });

        return LocationsModel;

    });

在视图初始化程序中，我尝试了以下绑定并在模型上监听，但它们似乎不会在响应后触发。

查看代码

model : new LocationModel(),

        initialize: function ()
    {
        console.log("Filter View - Initialize");
        this.render();
        this.listenTo(this.model, 'change', this.render); //this only fires at the start when the model is initialised
        this.model.on('change', this.render, this); //same as above
        this.listenTo(this.model, 'reset', this.render); //not fired at all
    },

对于一个系列来说，很容易听到发生的任何变化，但是对于 Backbone 个模型来说，这似乎是一个不同的球类游戏。

TLDR，如何获取视图以监听模型成功获取请求？

Answer 1

sync 事件是您想要listenTo 的事件。一旦 fetch 成功完成，它就会被触发。 Backbone 源中的这一行是罪魁祸首：Backbone source, line 578.

您的代码现在应该如下所示：

查看代码

model : new LocationModel(),

    initialize: function ()
{
    console.log("Filter View - Initialize");
    this.render();
    this.listenTo(this.model, "sync", this.render);
},

这里有一个 fiddle which shows your code working. I used httpbin 来模拟 POST 请求。您现在也可以删除获取请求中的 async: false 参数 :)（我已在 fiddle 示例中将其删除）。

Backbone 查看监听模型，更改或重置时不触发？

Backbone view listening to model, not firing on change or reset?

backbone.js

backbone-events

backbone-views

backbone-model