Key Components of Web2.0
August 12, 2009
3) REST(Representation State Transfer):
The term REST coined by Dr.Roy T.Fielding in his Ph.D. dissertation is defined as a software architecture intended to evoke an image of how a well designed web application behaves; A web application is a network of web pages through which the user progresses by traversing the hyperlinks changing the application client state from one to another. It can be explained s follows:
1)A client accesses any web resource by an URL.
2) The server responds by sending an HTML document which is the representation of the resource requested by the client.This represents one state of the client application.
3) When the client selects any link, it means the client is accessing another web resource.
This web resource again represents another state of the client application.
4) Thus the state of the client application goes on changing with the representation of each resource.
5) In order to implement web services in REST, first a resource should be created for that web service. That resource is accessed by an URL.
6) The web services should be designed in an interconnected manner.
Suppose for ex. want to get details of products from products-depot incorporate.
First in order to obtain Products List, the client accesses the URL, http://www.products-depot.com.
Next client selects Products List.www.products-depot.com/products-list
In order to obtain information about any one product, the client selects that product and navigates to another web resource,www.products-depot.com/products-list/07896…which is represented by URL 2 in the above diagram.The number mentioned is something like the id of the product.
7) From the preceding example, we find that REST is stateless as all information needs to be provided every time a web resource is accessed.
SOAP is a light weight protocol used for the exchange of XML-messages in a decentralized, distributed environment.