🛠️RESTfull API concepts

RESTful API design is centered around using standard HTTP protocols in a way that follows certain guiding principles.

Understanding these fundamentals can help you build scalable, efficient, and maintainable APIs. Here are a few key fundamentals of RESTful APIs. Understanding these fundamentals can help you design RESTful APIs that are easy to maintain, extend, and scale. They also ensure that your API can interact effectively with a variety of clients, from web browsers to mobile apps and more.

1. Resource-Based URLs

RESTful APIs are designed around resources, which are any kind of object, data, or service that can be accessed by the client. A resource has an identifier, which is the URL, and the operations you can perform on it are represented by HTTP methods. The URLs should be structured in a logical and predictable manner. For example, to get information about a user, you might use a URL like GET /users/{id}.

2. Use of HTTP Methods

RESTful APIs use standard HTTP methods to perform operations on resources. The primary methods used are:

• GET: Retrieve data from the server (e.g., list users, get user details).

• POST: Create a new resource on the server (e.g., create a new user).

• PUT or PATCH: Update an existing resource (PUT is typically used to update the entire resource, while PATCH is used for partial updates).

• DELETE: Remove a resource from the server.

3. Statelessness

In REST, every call from a client to a server must contain all the information the server needs to fulfill the request. The server should not store any session state about the client. This statelessness ensures that each API call can be understood in isolation, which simplifies the server design and improves scalability.

4. Cacheability

Responses from RESTful APIs should explicitly state whether they are cacheable or not. If responses are cacheable, the client can reuse the response data for equivalent responses in the future, which can significantly reduce the interaction latency and lessen the load on the server.

5. Layered System

REST allows you to structure your application into layers. Each layer does not know the inner details of other layers, thus ensuring that the architecture remains modular and manageable. For example, you might have a load-balancer at the top layer, followed by a caching layer, then your server, and maybe a database layer underneath.

6. Code on Demand (Optional)

While not mandatory, REST allows for code on demand as an optional feature. This principle lets servers extend client functionality by sending executable code to the client. For example, clients can download compiled components like Java applets or JavaScript code to run within the client.

7. Uniform Interface

One of the central principles of REST is having a uniform interface for interacting with resources. This simplifies and decouples the architecture, which enables each part to evolve independently. The uniform interface is characterized by the use of standard HTTP methods, resource-based URIs, media types for representing data, and stateless communication.

8. Use of Hypermedia (HATEOAS)

Hypermedia as the Engine of Application State (HATEOAS) is a constraint of REST application architecture that distinguishes it from most other network application architectures. With HATEOAS, a client interacts with a network application that application servers provide dynamically via hypermedia. A REST client needs minimal prior knowledge to interact with applications or servers. It discovers actions dynamically by reading hypermedia provided by server-driven applications.