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Showing posts with label WCF. Show all posts
Showing posts with label WCF. Show all posts

Wednesday, December 5, 2007

REST and WCF 3.5

The first version of WCF was focused on SOAP. But another approach known as REST is becoming a popular approach for building web services. The latest version of WCF in the .NET Framework 3.5 supports both SOAP and REST.

What is REST?

REST is an acronym standing for Representational State Transfer and it is an architecture style of networked systems. According to Roy Fielding (one of the principal authors of the Hypertext Transfer Protocol (HTTP) specification) , the explanation of Representational State Transfer is :
"Representational State Transfer is intended to evoke an image of how a well-designed Web application behaves: a network of web pages (a virtual state-machine), where the user progresses through an application by selecting links (state transitions), resulting in the next page (representing the next state of the application) being transferred to the user and rendered for their use." Systems that follow Fielding’s REST principles are commonly known as “RESTful”;

REST means that each unique URL is a representation of some object. You can get the contents of that object using an HTTP GET, to delete it, you then might use a POST, PUT, or DELETE to modify the object.

Unlike SOAP, REST is not a standard or specification. It is just an architectural style. You can design your web services using this architectural style.

REST is using the built-in operations in HTTP: GET, POST, and others. And rather than identify the information to be accessed with parameters defined in XML, as SOAP typically does, REST assumes that everything is identified with a URL. However REST is not a standard, it does use the following standards

  • HTTP

  • URL

  • XML/HTML/GIF/JPEG/etc (Resource Representations)

  • text/xml, text/html, image/gif, image/jpeg, etc

REST Vs SOAP - Which is the best approach?

Software Architects have been involving a never-ending debate about whether SOAP-based or REST-style web services are the right approach and recently the debate is too heating up. Yahoo's web services are using REST and google using SOAP for their web services. Some organizations have web services for both REST and SOAP. REST is Lightweight than SOAP because it does not requires lot of xml markup like SOAP.
I believe that SOAP will be the primary choice for intranet and enterprise level applications because SOAP and the WS-* specifications addresses many challenges of enterprise level applications such as reliability, distributed transactions, and other WS-* services. But I think open, Internet applications will gear towards to REST because of REST’s explicitly Web-based approach and its simplicity.

RESTful services for WCF 3.5

WCF 3.5 provides explicit support for RESTful communication using a new binding named WebHttpBinding.
The below code shows how to expose a RESTful service

[ServiceContract]
interface IStock
{
[OperationContract]
[WebGet]
int GetStock(string StockId);
}


By adding the WebGetAttribute, we can define a service as REST based service that can be accessible using HTTP GET operation.

Wednesday, November 28, 2007

New features of WCF in .Net 3.5

The upcoming .Net 3.5 framework has cool new features for WCF. Some of the new features are
1. Ajax enabled WCF web services.
2. Improved Support for WS-* Standards.
3. WCF designer for developing configuration files.
4. Support for REST-Style services.
5. Improved interaction between WF and WCF.

WCF Rocks !

WCF is Rocking in the SOA world. Many companies are adopting WCF as their platform for building Service Oriented Applications. Below are some of the clients that using WCF.

1. Avaya
2. Choicelinx
3. Crutchfield
4. FNAC
5. Kiwibank
6. Nike
7. OPC Foundation
8. OTTO
9. Pfizer
10. Schneider Electric
11. ST Electronics
12. Commonwealth of Massachusetts
13. Thomson Financial
14. Thomson Tax and Accounting
15. Tyco Fire and Security

JSON Supports in WCF with .Net 3.5

JSON (JavaScript Object Notation) is a lightweight data-interchange format. JSON is a text format language and becoming a common data-interchange standard for Ajax communication. Most of the Ajax applications are using JSON for communication between the client and server because JSON is faster than XML and easy to manipulate.

In .Net 3.5, WCF can supports JSON. You can send and receive JSON objects from WCF. You need to change config file to support JSON.

The following config that enables JSON support from WCF


<service name="OrderService">
<endpoint contract="IOrders"
binding="webHttpBinding"
bindingConfiguration="jsonBinding"
address=""
behaviorConfiguration="jsonBehavior" />
</service>

<webHttpBinding>
<binding name="jsonBinding" messageEncoding="Json" />
</webHttpBinding>
<behaviors>
<endpointBehaviors>
<behavior name ="jsonBehavior">
<webScriptEnable />
</behavior>
</endpointBehaviors>
</behaviors>