API AND REST API

What is API?

· Application programming interfaces (APIs) provide the platform and medium for applications to talk to and understand each other.

· APIs specify the way information passed across platforms is structured so that applications can exchange data and information.

· Each URL is called a request while the data sent back to you is called a response.

REST API (Representation State)

· Open-source web Automation Testing Technique.

· REST is an API architecture style.

· It is approach for communication used in the development of webservices.

· REST became the logical choice of building APIs.

· REST specifies how data is presented to a client in a format that is convenient for the client.

· Data exchanges happen either in JSON or XML format.

Set of recommendations and constraints for RESTful web services.

1.Client-Server: System A makes an HTTP request to a URL hosted by System B, which returns a response.

2.Stateless: REST is stateless, the client request should contain all the information necessary to respond to a request.

3.Cacheable: A response should be defined as cacheable or not.

4.Layered: The requesting client need not know whether it’s communicating with the actual server, a proxy, or any other intermediary.

How do REST APIs Work?

It uses method used to send request to the server. The four main methods that are associated with REST APIs are:

1.Get (Read)

2.Post (Create)

3.Put (Update)

4.Delete

1.Get: Extract Information from the server using a Url.

· It should only extract and should not have any effect on the data.

2.Post (Create): A Post request is used to create a new entity.

· It is similar to a creating a new record in the server.

3.Put: Modifying an entity

· It is similar to an updating on an existence one.

4.Delete: Remove the current entity

· It removes the current entity given by the url.