我有一个简单的单页面应用程序，供我自己学习。该页面包含我提供的所有服务的UL。此列表来自JSON。每个服务旁边都有一个价格，还有一个用户可以选择的复选框。
在列表下方，所选服务的总价格值。基于此，你能告诉我我做错了什么吗？我正在尝试将服务列表集成为车把模板。 这是HTML
<head>
<meta charset="utf-8" />
<title>Your first Backbone.js App | Tutorialzine </title>
<!-- Google web fonts -->
<link href="http://fonts.googleapis.com/css?family=PT+Sans:400,700" rel='stylesheet' />
<!-- The main CSS file -->
<link href="http://localhost/backbone-demo/assets/css/style.css" rel="stylesheet" />
</head>
<body>
<form id="main" method="post" action="submit.php">
<h1>My Services</h1>
<div id="serviceTable"></div>
<ul id="services">
<script id="services-template" type="text/x-handlebars-template">
<!-- The services will be inserted here via handlebars-->
{{#each services}}
<li>
<input type="checkbox" value="1" name="{{title}}"/> {{title}}
<span>${{price}} </span>
</li>
{{/each}}
</script>
</ul>
<p id="total">total: <span>$0</span></p>
<input type="submit" id="order" value="Order" />
</form>
<!-- JavaScript Includes -->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script src="http://localhost/backbone-demo/assets/js/libs/underscore.min.js"></script>
<script src="http://localhost/backbone-demo/assets/js/libs/backbone.min.js"></script>
<script src="http://localhost/backbone-demo/assets/js/libs/handlebars.js"></script>
<script src="http://localhost/backbone-demo/assets/js/script.js"></script>
</body>
这是Javascript：
$(function(){
// Create a model for the services
var Service = Backbone.Model.extend({
// Will contain three attributes.
// These are their default values
defaults:{
title: 'My service',
price: 100,
checked: false
},
// Helper function for checking/unchecking a service
toggle: function(){
this.set('checked', !this.get('checked'));
}
});
// Create a collection of services
var ServiceList = Backbone.Collection.extend({
// Will hold objects of the Service model
model: Service,
// Return an array only with the checked services
getChecked: function(){
return this.where({checked:true});
}
});
//Retrieve the list of services
$.ajax({
type: "GET",
url: "assets/services.json",
async: true,
success: function(response){
// Prefill the collection with a number of services.
var services = new ServiceList(response);
var ServiceView = Backbone.View.extend({
tagName: 'li',
events:{
'click': 'toggleService'
},
initialize: function(){
// Set up event listeners. The change backbone event
// is raised when a property changes (like the checked field)
this.listenTo(services, 'change', this.render);
},
render: function(){
var tpl = Handlebars.compile($("#services-template").html());
//console.log(this.$el.selector);
this.$el.html(tpl({services: services.toJSON()}));
//console.log(this.$el);
$('#serviceTable').append(this.$el);
//document.getElementById('serviceTable').innerHTML = serviceData;
// Create the HTML
/* this.$el.html('<input type="checkbox" value="1" name="' + this.model.get('title') + '" /> ' + this.model.get('title') + '<span>$' + this.model.get('price') + '</span>');
this.$('input').prop('checked', this.model.get('checked')); */
// Returning the object is a good practice
// that makes chaining possible
return this;
},
toggleService: function(){
this.model.toggle();
}
});
// The main view of the application
var App = Backbone.View.extend({
// Base the view on an existing element
el: $('#main'),
initialize: function(){
// Cache these selectors
this.total = $('#total span');
this.list = $('#services');
// Listen for the change event on the collection.
// This is equivalent to listening on every one of the
// service objects in the collection.
this.listenTo(services, 'change', this.render);
// Create views for every one of the services in the
// collection and add them to the page
services.each(function(service){
var view = new ServiceView({ model: service });
this.list.append(view.render().el);
}, this); // "this" is the context in the callback
},
render: function(){
// Calculate the total order amount by agregating
// the prices of only the checked elements
var total = 0;
console.log(services.getChecked());
Handlebars.each(services.getChecked(), function(elem){
console.log(total);
total += elem.get('price');
});
// Update the total price
this.total.text('$'+total);
return this;
}
});
new App();
}
});
}）;
答案 0 :(得分：0)
以下是您的代码的可行片段。您已经为集合中的每个服务定义了ServiceView，但是在此视图中，您正在使用整个集合，而不是this.model并且您的把手模板具有for循环它
这意味着您最终会显示集合的次数与集合中的模型一样多。下面的示例重复列表两次，因为列表中有2条记录。
有两种可能的解决方案：
将您的ServiceView重命名为ServicesView并删除App初始化中的循环。
移除模板中的循环并将通话更改为this.$el.html(tpl(this.model.toJSON()));
// Create a model for the services
var Service = Backbone.Model.extend({
// Will contain three attributes.
// These are their default values
defaults:{
title: 'My service',
price: 100,
checked: false
},
// Helper function for checking/unchecking a service
toggle: function(){
this.set('checked', !this.get('checked'));
}
});
// Create a collection of services
var ServiceList = Backbone.Collection.extend({
// Will hold objects of the Service model
model: Service,
// Return an array only with the checked services
getChecked: function(){
return this.where({checked:true});
}
});
//Retrieve the list of services
$.ajax({
type: "GET",
url: "http://www.mocky.io/v2/588b429d300000d11afa8d97",
async: true,
success: function(response){
// Prefill the collection with a number of services.
var services = new ServiceList(response);
var ServiceView = Backbone.View.extend({
tagName: 'li',
events:{
'click': 'toggleService'
},
initialize: function(){
// Set up event listeners. The change backbone event
// is raised when a property changes (like the checked field)
this.listenTo(services, 'change', this.render);
},
render: function(){
var tpl = Handlebars.compile($("#services-template").html());
//console.log(this.$el.selector);
this.$el.html(tpl({services: services.toJSON()}));
//console.log(this.$el);
$('#serviceTable').append(this.$el);
//document.getElementById('serviceTable').innerHTML = serviceData;
// Create the HTML
/* this.$el.html('<input type="checkbox" value="1" name="' + this.model.get('title') + '" /> ' + this.model.get('title') + '<span>$' + this.model.get('price') + '</span>');
this.$('input').prop('checked', this.model.get('checked')); */
// Returning the object is a good practice
// that makes chaining possible
return this;
},
toggleService: function(){
this.model.toggle();
}
});
// The main view of the application
var App = Backbone.View.extend({
// Base the view on an existing element
el: $('#main'),
initialize: function(){
// Cache these selectors
this.total = $('#total span');
this.list = $('#services');
// Listen for the change event on the collection.
// This is equivalent to listening on every one of the
// service objects in the collection.
this.listenTo(services, 'change', this.render);
// Create views for every one of the services in the
// collection and add them to the page
services.each(function(service){
var view = new ServiceView({ model: service });
this.list.append(view.render().el);
}, this); // "this" is the context in the callback
},
render: function(){
// Calculate the total order amount by agregating
// the prices of only the checked elements
var total = 0;
console.log(services.getChecked());
Handlebars.each(services.getChecked(), function(elem){
console.log(total);
total += elem.get('price');
});
// Update the total price
this.total.text('$'+total);
return this;
}
});
new App();
}
});<form id="main" method="post" action="submit.php">
<h1>My Services</h1>
<div id="serviceTable"></div>
<ul id="services">
<script id="services-template" type="text/x-handlebars-template">
<!-- The services will be inserted here via handlebars-->
{{#each services}}
<li>
<input type="checkbox" value="1" name="{{title}}"/> {{title}}
<span>${{price}} </span>
</li>
{{/each}}
</script>
</ul>
<p id="total">total: <span>$0</span></p>
<input type="submit" id="order" value="Order" />
</form>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/backbone.js/1.3.3/backbone-min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/handlebars.js/4.0.6/handlebars.min.js"></script>