javascript - 主干范围

Question

我已经调用了一个 View (menuview) 并将其传递给一个 var (prova)，但是从 View 调用它的结果是未定义的(console.log(this.model)，在 menuview 中)。谁能帮我找出错误？

路由器

      home: function() {
      new BarraScreamView();
      new MenuView();
       var self=this;


      var amicizie= new Amicizie();
      amicizie.fetch({
      success: function(object) {
     console.log(object);
     var prova=object.where({invitante: Parse.User.current().id,conferma:0});//mettere      
      invitato
     var num=prova.length;

     new MenuView({model:prova});<<<---------

     },
     error: function(amici, error) {

    }
    }); 

菜单 View

       var MenuView = Backbone.View.extend({

    el: $("#menu_container"),

    events: {

    },

    template: Handlebars.compile(template),

    initialize: function () {
        console.log(this.model);<<<------------


    this.render();
        console.log("menuview");

    },

Answer 1

原因很简单..

您似乎在 2 个地方创建了 MenuView() 的新实例

 home: function () {
     new BarraScreamView();
     new MenuView();     <----- First Instance here
     var self = this;
     var amicizie = new Amicizie();
     amicizie.fetch({
         success: function (object) {
             new MenuView({       <----- Second Instance here     
                 model: prova
             }); 

View 按照它们加载的顺序进行初始化。当您使用

创建新 View 时

new MenuView(); 会命中 View 的初始化方法

 initialize: function () {
        console.log(this.model);<<<------------
 }                   ^    ^
                     |    ------ Corresponds to the model passed in
                                 But there is nothing passed here
          corresponds to the view

所以它在第一种情况下记录未定义。