Restful API

REST or RESTful API design (representative state transfer) has appeared as the standard planning to design for web services and web APIs. REST APIs have become the most popular in recent years. Many client and browser apps to communicate with the server using the REST API.

REST API is an API for communication with web services that uses HTTP requests. As software developers, Most of us use or build the REST API every day of life.

What Is meant by RESTful?

An API that has the following features. Here are some of them:

• Client-server – The client is the front-end and the server is the back-end of the service. The client and server are independent and each of them can be replaced.                                                                           

• Stateless – no data is stored on the server-side from the client’s end.

• Cacheable – The client should have the ability to store responses in a cache and it improves the performance of the API.

• Uniform interface  – The Uniform Interface is a constraint that is placed on  REST services. It defines between clients and servers, there are four principles: Resource-Based, Actions on Resources Through Representations, Self-descriptive Messages, and Hypermedia as the Engine of Application State (HATEOAS).

• layered system – REST API allows using of layered system architecture to be composed of hierarchical layers by constraining component behavior. Here we can deploy the APIs on server X, and store data on the server Y and authenticate requests in Server Z.

• Code on Demand – Code on Demand allows for code in the form of applets or scripts.

Why Use a RESTful API?

The Aim of the RESTful API for enhancing the performance, portability, reliability, visibility, modifiability, scalability, and simplicity of the application. It is used to make applications distributed and independent over the internet.

Types of Requests:

In total, there are main types of actions, we are going to take by referencing to the API.          

Status Codes

Each call with the server returned a response in terms of status code. They briefly describe the result of the call. There are many numbers of status codes, Here are some of them:

• 200 – OK. The request was successful. The answer depends on API specification and the method (GET, POST, etc.).

• 204 – No Content. The request was successful, did not return any content.

• 400 – Bad Request. The server cannot process the request because of the client-side errors (incorrect request format).

• 401 – Unauthorized. This occurs when authentication was failed, due to incorrect credentials or even their absence.

• 403 – Forbidden. Access to the specified resource is denied.

• 404 – Not Found. resource not found on the server.

• 500 – Internal Server Error. This is a generic server error. This occurs when an unknown error has occurred on the server.

Accept and respond with JSON

JSON is the standard for transferring data. It is using in REST APIs to accept JSON for request payload and also send responses to JSON. Almost every networked technology can use it, JavaScript has built-in methods to encode and decode with JSON either through the Fetch API or another HTTP client. Server-side have libraries that can decode JSON without doing much work.

Characteristics of a well-designed API

       Making an effective API design for using the following characteristics:

• Easy to learn: A well-designed API will be easy to Understand for developers and users as well.

• Hard to misuse: design should be a straightforward process with Implementing and integrating with an API. writing incorrect code will be a less probable end result. It has informative feedback and doesn’t enforce strict guidelines on the API’s end consumer.

• API should satisfy the requirements: when making the API and if you are in a doubt leave it out because conceptual weight is more important then bulk. 

• Easy to read and maintain the code: For the developer point it is most important. If the API is well structured then the developer has understood and modified easily.

• Have Good Documentation: Good documentation is last but not least and it is always better than no documentation or bad documentation. Good documentation is a good option for developers to understood API. It providing good information, extensive documentation about the API.

Conclusion

The API is the best way to communicate with the server. If they are incorrectly designed, this can lead to confusion so the best effort is to design well and the rest is just implementation. Add documentation because it is important for a better understanding of the API.