ASP.NET Web API & Backbone (1) —— Web API & Simple Get
.NET 4.5 中的 ASP.NET Web API 使得我们可以快速搭建基于REST风格的服务应用，利用强大的客户端框架 Backbone 我们可以采用MVC的设计思路，
组织客户端Javascript模块(功能) 从而实现快速灵活的应用开发。
【服务端 Web API】
为了演示我设计了一个简单的应用：留言簿
首先是服务端的 Model：
[csharp]
namespace BackboneAndWebApi.Models
{
public class Comment
{
public Comment() { }
public Comment(string text, string author)
{
Text = text;
Author = author;
}
public int ID { get; set; }
[Required]
public string Text { get; set; }
[Required]
[StringLength(10, ErrorMessage = "Author is too long! This was validated on the server.")]
public string Author { get; set; }
[Required]
public string Email { get; set; }
public string GravatarUrl
{
get
{
return HttpUtility.HtmlDecode(Gravatar.GetUrl(Email ?? "", 40, defaultImage: "retro", rating: GravatarRating.G));
}
set { }
}
}
}
namespace BackboneAndWebApi.Models
{
public class Comment
{
public Comment() { }
public Comment(string text, string author)
{
Text = text;
Author = author;
}
public int ID { get; set; }
[Required]
public string Text { get; set; }
[Required]
[StringLength(10, ErrorMessage = "Author is too long! This was validated on the server.")]
public string Author { get; set; }
[Required]
public string Email { get; set; }
public string GravatarUrl
{
get
{
return HttpUtility.HtmlDecode(Gravatar.GetUrl(Email ?? "", 40, defaultImage: "retro", rating: GravatarRating.G));
}
set { }
}
}
}当然要有增删改查，于是有了下面的 Repository 接口
[csharp]
namespace BackboneAndWebApi.Models
{
public interface ICommentRepository
{
IEnumerable<Comment> Get();
bool TryGet(int id, out Comment comment);
Comment Add(Comment comment);
bool Delete(int id);
bool Update(Comment comment);
}
}
namespace BackboneAndWebApi.Models
{
public interface ICommentRepository
{
IEnumerable<Comment> Get();
bool TryGet(int id, out Comment comment);
Comment Add(Comment comment);
bool Delete(int id);
bool Update(Comment comment);
}
}具体实现采用内存数据存储：
[csharp]
namespace BackboneAndWebApi.Models
{
public class DictionaryCommentRepository : ICommentRepository
{
int nextID = 0;
Dictionary<int, Comment> comments = new Dictionary<int, Comment>();
public IEnumerable<Comment> Get()
{
return comments.Values.OrderBy(comment => comment.ID);
}
public bool TryGet(int id, out Comment comment)
{
return comments.TryGetValue(id, out comment);
}
public Comment Add(Comment comment)
{
comment.ID = nextID++;
comments[comment.ID] = comment;
return comment;
}
public bool Delete(int id)
{
return comments.Remove(id);
}
public bool Update(Comment comment)
{
bool update = comments.ContainsKey(comment.ID);
comments[comment.ID] = comment;
return update;
}
}
}
namespace BackboneAndWebApi.Models
{
public class DictionaryCommentRepository : ICommentRepository
{
int nextID = 0;
Dictionary<int, Comment> comments = new Dictionary<int, Comment>();
public IEnumerable<Comment> Get()
{
return comments.Values.OrderBy(comment => comment.ID);
}
public bool TryGet(int id, out Comment comment)
{
return comments.TryGetValue(id, out comment);
}
public Comment Add(Comment comment)
{
comment.ID = nextID++;
comments[comment.ID] = comment;
return comment;
}
public bool Delete(int id)
{
return comments.Remove(id);
}
public bool Update(Comment comment)
{
bool update = comments.ContainsKey(comment.ID);
comments[comment.ID] = comment;
return update;
}
}
}利用 Ninject 在 WebAPI 初始化时注入（InitialData 是 DictionaryCommentRepository 的子类，构造函数中加一些初始数据）
[csharp]
namespace BackboneAndWebApi
{
public static class WebApiConfig
{
public static void Register(HttpConfiguration config)
{
config.Filters.Add(new ValidateAttribute());
IKernel kernel = new StandardKernel();
kernel.Bind<ICommentRepository>().ToConstant(new InitialData());
config.DependencyResolver = new NinjectResolver(kernel);
config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{id}",
defaults: new { id = RouteParameter.Optional }
);
}
}
}
namespace BackboneAndWebApi
{
public static class WebApiConfig
{
public static void Register(HttpConfiguration config)
{
config.Filters.Add(new ValidateAttribute());
IKernel kernel = new StandardKernel();
kernel.Bind<ICommentRepository>().ToConstant(new InitialData());
config.DependencyResolver = new NinjectResolver(kernel);
config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{id}",
defaults: new { id = RouteParameter.Optional }
);
}
}
}
CommentsController 是 Web API 的实现类，实现了简单的GET
[csharp]
namespace BackboneAndWebApi.Controllers
{
public class CommentsController : ApiController
{
ICommentRepository repository;
public CommentsController(ICommentRepository repository)
{
this.repository = repository;
}
#region GET
[Queryable]
public IQueryable<Comment> GetComments()
{
return repository.Get().AsQueryable();
}
public Comment GetComment(int id)
{
Comment comment;
if (!repository.TryGet(id, out comment))
throw new HttpResponseException(new HttpResponseMessage(HttpStatusCode.NotFound));
return comment;
}
#endregion
}
}
namespace BackboneAndWebApi.Controllers
{
public class CommentsController : ApiController
{
ICommentRepository repository;
public CommentsController(ICommentRepository repository)
{
this.repository = repository;
}
#region GET
[Queryable]
public IQueryable<Comment> GetComments()
{
return repository.Get().AsQueryable();
}
public Comment GetComment(int id)
{
Comment comment;
if (!repository.TryGet(id, out comment))
throw new HttpResponseException(new HttpResponseMessage(HttpStatusCode.NotFound));
return comment;
}
#endregion
}
}
发布后，用Fiddler测试（别忘记加上 Accept: application/json 的Header，这样才会返回json格式的数据）
【客户端】
先加入 Backbone，可以上官网自己下载，或者直接用 Nuget : Install-Package Backbone.js
通过下面的 HTML 可以对 Backbone 进行初步的理解：
这个“留言簿” 定义为 CommentModel 和 CommentView，View负责页面的描绘，Model则是对应服务端实体，model.fetch 取得数据，view.render 将取到的数据交给
underscore 的 template 生成HTML结果。其他一些细节请看下面代码中的注释。
[html]
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Comments Test Home Page</title>
<link href="/Content/Demo.css" rel="stylesheet" type="text/css" />
<script src="Scripts/jquery-1.9.0.min.js"></script>
<script src="Scripts/underscore-1.4.3.js"></script>
<script src="Scripts/backbone-0.9.9.js"></script>
</head>
<body>
<nav>
<p class="demo-navigation">
<a href="default.htm"><<< Back</a>
| Demo 1 Simple Get |
<a href="demo2-crud.htm">On to Demo 2 - Simple CRUD >>></a>
</p>
</nav>
<p id="content">
<p id="demo-actions">
<p>
<legend>Get Comments Demos</legend>
<button id="getComments">Go!</button>
</p>
</p>
<p id="article">
<p>
This first demo shows a very simple GET scenario. Click on the button to
use jQuery to retrieve JSON data from a Web API endpoint and then display
the contents of that payload in the UI.
</p>
<p>
The code represents retrieving data in a manner that any developer familiar
with jQuery would understand.
</p>
</p>
<ul id="comments">
</ul>
<!-- 模板 -->
<script id="commentTemplate" type="text/html">
<% _.each(comments, function(item) { %>
<li class="comment">
<header>
<p class="info">
<img src='<%= item.GravatarUrl %>' />
<strong><span><%= item.Author %></span></strong>
</p>
</header>
<p class="body">
<p><%= item.Text %></p>
</p>
</li>
<% }); %>
</script>
<script type="text/javascript">
var CommentModel = Backbone.Model.extend({
// model 对应服务端的API URL
url: 'api/comments'
});
var CommentView = Backbone.View.extend({
// 将body作为一个View
el: 'body',
// 加载模板
template: _.template($('#commentTemplate').html()),
// 绑定HTML上"Go!"按钮，调用 model.fetch 获取数据
// model.fetch 会调用 Backbone.sync('read', model, options) 里面封装了ajax
events: {
'click #getComments': function () {
this.model.fetch();
}
},
initialize: function () {
this.model.on('change', this.render, this);
},
render: function () {
var data = this.model.toJSON();
$('#comments').html(this.template({ comments: data }));
return this;
}
});
$(function () {
var view = new CommentView({ model: new CommentModel() });
});
</script>
</p>
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Comments Test Home Page</title>
<link href="/Content/Demo.css" rel="stylesheet" type="text/css" />
<script src="Scripts/jquery-1.9.0.min.js"></script>
<script src="Scripts/underscore-1.4.3.js"></script>
<script src="Scripts/backbone-0.9.9.js"></script>
</head>
<body>
<nav>
<p class="demo-navigation">
<a href="default.htm"><<< Back</a>
| Demo 1 Simple Get |
<a href="demo2-crud.htm">On to Demo 2 - Simple CRUD >>></a>
</p>
</nav>
<p id="content">
<p id="demo-actions">
<p>
<legend>Get Comments Demos</legend>
<button id="getComments">Go!</button>
</p>
</p>
<p id="article">
<p>
This first demo shows a very simple GET scenario. Click on the button to
use jQuery to retrieve JSON data from a Web API endpoint and then display
the contents of that payload in the UI.
</p>
<p>
The code represents retrieving data in a manner that any developer familiar
with jQuery would understand.
</p>
</p>
<ul id="comments">
</ul>
<!-- 模板 -->
<script id="commentTemplate" type="text/html">
<% _.each(comments, function(item) { %>
<li class="comment">
<header>
<p class="info">
<img src='<%= item.GravatarUrl %>' />
<strong><span><%= item.Author %></span></strong>
</p>
</header>
<p class="body">
<p><%= item.Text %></p>
</p>
</li>
<% }); %>
</script>
<script type="text/javascript">
var CommentModel = Backbone.Model.extend({
// model 对应服务端的API URL
url: 'api/comments'
});
var CommentView = Backbone.View.extend({
// 将body作为一个View
el: 'body',
// 加载模板
template: _.template($('#commentTemplate').html()),
// 绑定HTML上"Go!"按钮，调用 model.fetch 获取数据
// model.fetch 会调用 Backbone.sync('read', model, options) 里面封装了ajax
events: {
'click #getComments': function () {
this.model.fetch();
}
},
initialize: function () {
this.model.on('change', this.render, this);
},
render: function () {
var data = this.model.toJSON();
$('#comments').html(this.template({ comments: data }));
return this;
}
});
$(function () {
var view = new CommentView({ model: new CommentModel() });
});
</script>
</p>
</body>
</html>运行结果：
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