访问模板中的属性时出现问题-除'name'显示错误'没有定义[attributename];

Trouble accessing attributes in the template - all attributes apart from 'name' show error '[attributename] is not defined'

本文关键字:显示 name 错误 attributename 定义 属性 问题 访问      更新时间:2024-06-28

问题是,当从模板访问时,除了"name"之外的所有Object属性都会在控制台中调用错误"id/url/athing is not defined"。只有"name"的模板显示良好并显示正确的名称,但一旦我调用不同的属性,例如idurl,它就会中断。传递给视图的对象是一个经过解析的静态JSON文件,所有项目都位于同一级别,可以通过控制台访问,例如collectionName.models[0].get('id');

让我感到困惑的是,name属性是有效的,就好像它是在主干/下划线代码中的某个地方预定义的一样。

我是不是错过了一些显而易见的东西?由于我可以从控制台访问模型数据,我认为视图本身处理数据的方式有问题,但我尝试过用几种不同的方式重写它,但似乎没有什么不同。


所有相关代码。

传递的对象格式。这也是collectionName.models[0].attributes;在控制台中返回的内容。

[{
"id":"0",
"name": "Building1",
"url": "building_1",
"floors":[{
    "id":"0",
    "name":"Ground Floor",
    "image":"",
    "rooms":[{
        "id": "r_1",
        "name": "Room 1",
    },
    {
        "id": "r_2",
        "name": "Room 2"
    }]
}
}]

}

示例模板代码:

<span class="name"><%= name %></span>
<%= id %> <%= url %>

路由器代码:

routes: {
  '': 'intro', // this route is using pretty much identical code and works fine, the model has the exact same format, the only difference is that all attributes work.
  ':id': 'firstLevel'    
},
firstLevel: function  (id) {
  window.singleBuilding = new ThisBuilding({}, {idBuilding: id});
  window.singleBuilding.fetch();      
  this.floorView = new FloorList({
    collection: window.singleBuilding
  });
  var $intro = $('#intro');
  $intro.empty();
  $intro.append(this.floorView.render().el);
}

视图:

window.FloorSingleList = Backbone.View.extend({
  className: 'floor-list',
  initialize: function  () {
  this.template = _.template(tpl.get('floors-list-item')); 
  _.bindAll(this, 'render');
  this.model.bind('change', this.render);
  this.testModel = this.model.attributes; // I tried passing the attributes directly to the templatewithout .toJSON(), which worked exactly the same, as in only the 'name' attribute worked
},
render: function  () {
  console.log("The test data is:", this.testModel);
  console.log("The actual model data is:", this.model);
  var renderedContent = this.template(this.model.toJSON());
  $(this.el).html(renderedContent);
  return this;
 }
});
window.FloorList = Backbone.View.extend({
tagName: 'section',
className: 'intro-list',
initialize: function () {
  this.template = _.template(tpl.get('intro-list'));
  _.bindAll(this, 'render');
  this.collection.bind('reset', this.render, this);
  this.collection.bind('change', this.render, this);
},
render: function  (eventName) {
     var $introList;
     var collection = this.collection;
  $(this.el).html(this.template({ }));
  $introList = this.$('.intro-list');
  collection.each(function (building) {
    var view = new FloorSingleList({
      model: building,
      collection: collection
    });
    $introList.append(view.render().el);
  });
  return this;
}
});

型号代码:

window.ThisBuilding = Backbone.Collection.extend({
model : Building,
initialize: function(models, options) {
  // Initialising the argument passed on from the router.
  this.idBuilding = options.idBuilding;
  return this;
},
url : function(){
  return  "data.json"      
},
parse: function (response) {
  console.log("Passed parameters are :", this.idBuilding); // Returns the request parameters passed from the router.
  return response[this.idBuilding];
}
});

模板&引导

// templates are loaded during the bootstrap 
tpl.loadTemplates(['header', 'intro-list', 'floors-list-item', 'building-list-item'], function() {
    window.App = new ExampleApp();
    Backbone.history.start();
});

问题在于javascript中的fetch是如何异步的。。。

firstLevel: function  (id) {
  window.singleBuilding = new ThisBuilding({}, {idBuilding: id});
  window.singleBuilding.fetch();  // YOU FETCH HERE     
  this.floorView = new FloorList({
    collection: window.singleBuilding
  });
  var $intro = $('#intro');
  $intro.empty();
  $intro.append(this.floorView.render().el); // AND RENDER WHILE YOU CAN'T ASCERTAIN THE FETCH HAS BEEN COMPLETED...
}

因此,渲染会尝试读取尚未正确初始化的集合->您的模型尚未完成->有趣的读数。控制台日志在异步操作方面发挥着神奇的作用。所以它可能告诉你一些事情,而现实是完全不同的。所以改为这样做:

firstLevel: function  (id) {
  window.singleBuilding = new ThisBuilding({}, {idBuilding: id}); 
  // Don't fetch here...   
  this.floorView = new FloorList({
    collection: window.singleBuilding
  });
  var $intro = $('#intro');
  $intro.empty();
  $intro.append(this.floorView.el); // Don't render here
}

然后在FloorList-视图中:

initialize: function () {
  this.template = _.template(tpl.get('intro-list'));
  _.bindAll(this, 'render');
  this.collection.bind('reset', this.render, this);
  this.collection.bind('change', this.render, this);
  this.collections.fetch(); // fetch here, your binds take care of rendering when finished
}

更新2:显然,我看到了没有复杂性的地方。。。忽略下面的所有内容

来自Backbone.js文档,在Model.toJSON()

返回用于JSON字符串化的模型属性的副本。

因此,它以JSON的形式返回属性。现在主干网将id定义为

模型的一个特殊属性。。。

属性,而不是属性。url也是如此。在表示骨干模型的javascript对象中,属性存储在对象中自己的对象中,id和url属性存储在模型对象的其他位置。例如,表示您的模型的javascript对象可能看起来像这样:

{
  ...
  attributes: Object // this is where your name attribute lives
  ...
  id: 34, // this is your id property
  ...
  __proto__: ctor, // this is where your url-function resides
  ...
}

UPDATE:id属性嵌入到model.toJSON()中的JSON中

因此,当您执行this.model.toJSON()时,您可以根据模型对象属性属性的内容创建一个JSON,并包含id属性。url-属性不包含在其中。你可以做什么,例如:

var renderedContent = this.template({
  attributes: this.model.toJSON(),
  url: this.model.url()
});

并且在模板中

<span class="name"><%= attributes.name %></span>
<%= attributes.id %> <%= url %>

希望这能有所帮助!