An Introduction to RESTful Web Services

REST stands for Representational State Transfer

Like in any other product's successful development, an architectural design plays an important role and it is mostly for describing the features of how that product will be built. Software also demands such kinds of architecture or we can architectural design that simply by building an environment of software by describing the features that are the guidelines to implement the software.

REST Background

The concept of REST was first coined by Roy Thomas Fielding in 2000, he was one of the people working on HTTP. The reason why I am providing a little information about Fielding is only because our REST-based services are also implemented on a specification on which the internet depends, HTTP. REST is built on a client-server architectural style.

To learn how REST works we should understand how the web works, since REST uses the web, specifically HTTP.

HTTP Verbs

To interact with resources and their representations REST uses the HTTP communication protocol that defines a set of standard method (verbs), headers and status codes like 404, 402 and so on.

• HTTP Verbs
  
  • GET
    GET basically requests a resource representation.
    
  • POST
    POST actually works for submitting the data that must be processed at an endpoint (resource).
    
  • DELETE
    DELETE allows to delete a resource.
    
  • PUT
    Create or update a resource.
    
  • HEAD
    Use to retrieve the header, its works similar to GET, in other words to retrieve something. The only difference is HEAD retrieves only headers but GET retrieves the body.
    
  • OPTIONS
    Returns supported methods by resource.
    
  More precisely, GET, POST, DELETE and PUT provide the basic CRUD operations for the web whereas HEAD and OPTIONS provide the ability to retrieve metadata (MSDN).
  
• HTTP Status Codes
  
  
  

• resources
• URI

In REST what actually happens is that the user interacts with resources via a unique Uniform Resorce Identifier (URI). A URI is how named or represented resources are addressed. Resource interaction ids are done using HTTP verbs (GET, POST, PUT and DELETE), we can also include resource types (XML, JSON, JPG and PNG) as HTTP content.

Let's create a RESTFul service.

Create > New Project > WCF > WCF Service Application



Delete the services created by default.