这是我的一些代码(它还没有做任何事情).奇怪的是,在点击“/#用户”的URL时,没有错误.错误发生的唯一时间是当我点击去另一个哈希,然后点击返回到“/#用户”.这是我的代码的一部分,线路接收到最终的错误Users = new Users();错误说“用户不是构造函数”：
var User = Backbone.Model.extend({
url: function(){return 'api/user/id/' + this.id;}
});
var Users = Backbone.Collection.extend({
model: User,url: function(){return 'api/users';},initialize: function() {
}
});
var UsersView = Backbone.View.extend({
initialize: function() {
this.users = this.options.users;
this.render();
},render: function() {
_(this.users).each(function(){
// $('#app').append('here');
});
var template = _.template($('#userstemplate').text());
$(this.el).html(template({users: this.users}));
$('#app').html(this.el);
}
});
var UserView = Backbone.View.extend({
initialize: function() {
this.user = this.options.user;
this.render();
},render: function() {
var template = _.template("hello {{user.name}}");
$(this.el).html(template({user: this.user.toJSON()}));
$('#app').html(this.el);
}
});
var Controller = Backbone.Controller.extend({
routes: {
'dashboard' : 'dashboard','users' : 'showusers'
},showuser: function(id) {
UserList.fetch({
success: function(){
new UserView({user: User});
},error: function(){
alert('an error of sorts');
}
});
},showusers: function() {
Users = new Users();
Users.fetch({
success: function(Users) {
new UsersView({users: Users});
},error: function() {
}
});
},dashboard: function() {
Users = new Users;
Users.fetch({
success: function() {
new UsersView({users: Users});
},error: function() {
}
});
}
});
$(document).ready(function(){
var ApplicationController = new Controller;
Backbone.history.start();
});
如果你好奇,附带的html：
<!DOCTYPE html>
<html lang="en">
<head>
<Meta charset="utf-8">
<title>Administration Panel</title>
<!-- Framework -->
<script src="/javascripts/jquery.min.js"></script>
<script src="/javascripts/underscore.min.js"></script>
<script src="/javascripts/backbone.js"></script>
<!-- Application -->
<script src="/javascripts/application.js"></script>
<script id="userstemplate" type="text/x-underscore-template">
asdf
</script>
</head>
<body>
<div>
<a href="#dashboard">Dashboard</a>
<a href="#users">Users</a>
<a href="#products">Products</a>
<a href="#orders">Orders</a>
<a href="#pages">Pages</a>
<a href="#settings">Settings</a>
</div>
<div id="app"></div>
</body>
</html>
解决方法
new {} // Error: ({}) is not a constructor
在上下文中检查用户的类型：当引发异常时,它不是Function.
快乐的编码
alert(typeof(Users))应该做的伎俩.结果应该是“函数”可用作构造函数.记下在失败的情况下是什么,看下面的原因.
一个有问题的场景(用户=新用户)可能是：一个对象是从“功能用户”构建的,然后将对象(现在不是一个功能/构造函数)分配给用户,以便下一个新的用户将去kaboom！ (看看这两个showusers和仪表板 – 那个行为真的有意义吗？)
“正确”代码很可能：var users = new Users; users.blahblah(…);也就是说,使用新的局部变量,并且不覆盖全局用户变量/属性.
仅当“返回”为“#foobar”(Fragment Identifier)时才会生成错误的原因是没有新页面实际加载,因此JavaScript未被重新加载,并且正在使用当前(现在已损坏的用户). KABOOM！
摘自Fragment Identifier：
If the targeted element is located in the current document,a user agent may simply focus the targeted element without having to reload it …