Significance of REST API

 

Since the invention of the Internet, we have used various applications and web pages to get data for various resources. However, have you ever wondered where this data comes from? Well, these are the servers that we get the data from. So, in this article on What is REST API, we take a look at how a client communicates with servers to extract the required information.

Objectives

• Importance of REST API?
• What is REST API?
• Principles of REST API?
• Methods of REST API?

Importance of REST API

Consider an example where you are using the PAYTM app that most of us use on a daily basis, in this example you are using it to book movie tickets. Obviously, this application needs a lot of input data because the data present in the application is never static as it gets different languages ​​at different times of the day. It is never static, which means that the data is constantly changing in these applications.

Now, where do you think we get this data from?

Well, this data is received by the server or more commonly known as a web server. Then the client requests the requested data from the server, through an API like a news API to get relevant news data, then the server sends a response to the client.

Here, the response sent to the client is in the form of an HTML web page. But do you think this is an appropriate response you would expect when submitting an application?

Well, I guess you’re saying NO. As you would prefer the data to be returned in a structured format, rather than the raw news data on the full web page.

Therefore, for these reasons, the data returned by the server, in response to the client’s request, is either in JSON format like Newsdata.io’s JSON news API that gives news data in JSON format or in XML format. Both JSON and XML formats have a proper hierarchical data structure.

Now that sounds pretty simple, doesn’t it?

But the only problem that is present in this case so far is that you have to use many methods to get the required information. In fact, using these methods to retrieve information becomes quite painful when complex data is required.

So this is where the REST API comes in. The REST API creates an object and then sends the values ​​of an object in response to the client. Now that you know the need for REST, later in this article, let’s take a look at the REST API?

What is REST API?

REST suggests creating a data object requested by the client and sending the object’s values ​​in response to the user. For example, if the user requests a movie from Bangalore at a certain location and at a certain time, a server-side object can be created.

So here you have an object and you send the status of an object. This is why REST is known as Representational State Transfer.

If I have to define REST, then Representational State Transfer aka REST is an architectural style as well as an approach for communication purposes that is often used in the development of various web services.

REST’s architectural style takes advantage of low bandwidth usage to make an application more Internet-friendly. It is often considered the “language of the Internet” and is entirely resource-based.

To better understand, let’s dig a little deeper and see how exactly a REST API works. Basically, the REST API splits a transaction to create small modules. Now each of these modules is used to process a specific part of the transaction. This approach offers more flexibility but requires a lot of effort to build from scratch.

So now that you know what the REST API is, let’s try to understand the constraints or the principles that must be respected for an application to be considered a REST API.

Principles of REST API

Well, there are six basic principles established by Dr. Fielding, who defined the design of the REST API in 2000. Below are the six guiding principles of REST:

Stateless

The requests sent by a client to a server will contain all the information necessary for the server to understand the requests sent by the client. This could be part of the URL, query string parameters, body, or even headers.

The URL is used to uniquely identify the resource, and the body maintains the status of the requesting resource. After the server processes the request, a response is sent to the client through the body, state, or headers.

Client-Server

The client-server architecture allows a uniform interface and separates clients from servers. This improves the portability and cross-platform scalability of server components.

Uniform Interface

To ensure consistency throughout the application, REST has the following four interface constraints:

• Resource identification
• Resource Manipulation using representations
• Self-descriptive messages
• Hypermedia as the engine of application state

Cacheable

In order to provide a better performance, applications are often cached. This is done by labeling the response from the server as either cacheable or not, either implicitly or explicitly. If the response is set to be cacheable, the client cache can reuse the data response for equivalent responses in the future.

Layered system

The layered system architecture allows an application to be more stable by limiting the behavior of the components. This type of architecture helps improve application security because components at each level cannot interact beyond the next immediate level in which they are located. It also enables load balancing and provides shared caches to aid scalability.

Code on demand

This is an optional constraint and the least used. Allows you to download a client’s code or applets and use them in the app. Essentially, it simplifies customers by building a smart app that doesn’t rely on its own design code.

Now that you know the REST API principles, let’s take a look at the REST API methods.

Methods of REST API

All of us who work with web technology do CRUD operations. When I say CRUD operations, I mean we create a resource, read a resource, update a resource, and delete a resource. Now, to perform these actions, you can actually use HTTP methods, which are nothing more than REST API methods. Refer below.