A simple
and straight forward article taken from:
http://christopherdeweese.com/blog2/post/drop-the-soap-wcf-rest-and-pretty-uris-in-net-4
Drop
the Soap: WCF, REST,
and Pretty URIs in .NET 4
Years ago I was working in libraries when
the Web 2.0 revolution began. One of
the things that caught my attention about early start-ups using
the AJAX/REST/Web 2.0 model was how nice
the URIs were for their applications. Those were my first impressions of REST; pretty URIs. Turns out there is a little more to it than that.
REST is an architectural style that focuses on resources
and structured ways to access those resources via
the web. REST evolved as an “anti-SOAP” movement, driven by developers who did not want to deal with all
the complexity SOAP introduces (which is al lot when you don’t have frameworks hiding it all). One of
the biggest benefits to REST is that browsers can talk to rest services directly because REST works using URIs, QueryStrings, Cookies, SSL,
and all those HTTP verbs that we don’t have to think about anymore.
If you are familiar with ASP.NET MVC then you have been exposed to rest at some level. MVC is relies heavily on routing to generate consistent
and clean URIs. REST for WCF gives you
the same type of feel for your services. Let’s dive in.
WCF REST in .NET 3.5 SP1
and .NET 4
This post will cover WCF REST in .NET 4 which drew heavily from
the REST Starter Kit
and community feedback. There is basic REST support in .NET 3.5 SP1
and you can also grab
the REST Starter Kit to enable some of
the features you’ll find in .NET 4.
This post will cover REST in .NET 4
and Visual Studio 2010.
Getting Started
To get started we’ll create a basic WCF Rest Service Application using
the new on-line templates option in VS 2010:
When you first install a template you are prompted with this dialog:
Dude Where’s my .Svc File?
The WCF REST template shows us
the new way we can simply build services. Before we talk about what’s there, let’s look at what is not there:
The .Svc File
An Interface Contract
Dozens of lines of configuration that you have to change to make your service work
REST in .NET 4 is greatly simplified
and leverages
the Web Routing capabilities used in ASP.NET MVC
and other parts of
the web frameworks. With REST in .NET 4 you use a global.asax to set
the route to your service using
the new ServiceRoute class. From there,
the WCF runtime handles dispatching service calls to
the methods based on
the Uri Templates.
global.asax
using System;
using System.ServiceModel.Activation;
using System.Web;
using System.Web.Routing;
namespace Blog.WcfRest.TimeService
{
public class Global : HttpApplication
{
void Application_Start(object sender, EventArgs e)
{
RegisterRoutes();
}
private static void RegisterRoutes()
{
RouteTable.Routes.Add(new ServiceRoute("TimeService",
new WebServiceHostFactory(), typeof(TimeService)));
}
}
}
The web.config contains some new structures to support a configuration free deployment. Note that this is
the default config generated with
the template. I did not make any changes to web.config.
web.config
<?xml version="1.0"?>
<configuration>
<system.web>
<compilation debug="true" targetFramework="4.0" />
</system.web>
<system.webServer>
<modules runAllManagedModulesForAllRequests="true">
<add name="UrlRoutingModule" type="System.Web.Routing.UrlRoutingModule,
System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
</modules>
</system.webServer>
<system.serviceModel>
<serviceHostingEnvironment aspNetCompatibilityEnabled="true"/>
<standardEndpoints>
<webHttpEndpoint>
<!--
Configure
the WCF REST service base address via
the global.asax.cs file
and the default endpoint
via
the attributes on
the <standardEndpoint> element below
-->
<standardEndpoint name="" helpEnabled="true" automaticFormatSelectionEnabled="true"/>
</webHttpEndpoint>
</standardEndpoints>
</system.serviceModel>
</configuration>
Building
the Time Service
We’ll create a simple “TimeService” that will return
the current time. Let’s start with
the following code:
using System;
using System.ServiceModel;
using System.ServiceModel.Activation;
using System.ServiceModel.Web;
namespace Blog.WcfRest.TimeService
{
[ServiceContract]
[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
[ServiceBehavior(InstanceContextMode = InstanceContextMode.PerCall)]
public class TimeService
{
[WebGet(UriTemplate = "CurrentTime")]
public string CurrentTime()
{
return DateTime.Now.ToString();
}
}
}
The endpoint for this service will be http://[machinename]:[port]/TimeService. To get
the current time http://[machinename]:[port]/TimeService/CurrentTime will do
the trick.
The Results Are In
Remember That Route In global.asax?
Turns out it is pretty important. When you set
the route name, that defines
the resource name starting after
the host portion of
the Uri.
Help Pages in WCF 4
Another feature that came from
the starter kit are
the help pages. To access
the help pages simply append Help to
the end of
the service’s base Uri.
Dropping
the Soap
Having dabbled with REST in
the past
and after using Soap for
the last few years,
the WCF 4 REST support is certainly refreshing. I’m currently working on some REST implementations in .NET 3.5
and VS 2008
and am looking forward to working on REST in .NET 4
and VS 2010.
