REST API is an application programming interface. It contains rules that define how an application and a device can communicate and connect with each other. Its knowledge is essential for backend developers nowadays. What exactly is REST API and when is it used?
What is REST API?
The name of the interface comes from the combination of two words. The first one is REST. It is a style of software architecture, which is based on predefined rules. They describe how to define resources and rules of access to them. Its beginnings date back to the year 2000, when Roy Finger published his doctoral thesis on this topic. This style allows developers to work with great flexibility and freedom. An API, in turn, is a set of rules that defines how communication occurs between computer systems as well as between a human and a computer system.
HTTP methods used in REST API
HTTP protocol is also inextricably linked with REST API. It is used in web design. When developing a REST API, the following HTTP methods are used for communication: CONNECT, DELETE, GET, HEAD, OPTIONS, PATCH, POST, PUT, TRACE. However, only four of them are necessary in the basic version:
- GET – is to retrieve the indicated resource according to the given identifier.
- POST – creates a new resource. It is used to create all sorts of operations that other methods do not match. It can also fetch data when additional parameters need to be provided in the body.
- PUT – based on an identifier, updates the resource and can create a new resource if its identifier is known.
- DELETE – aims to delete the specified resource according to the identifier.
REST API Working Principle
The REST API workflow can be defined as follows. A request is prepared by the client in the form of an address – endpoint. Then it prepares a request. After receiving it by the system, a response is prepared. The next step is to return the response to the client by the system. The last one is receiving and processing it by the client.
Why is it worth using the REST API?
There are many advantages of using REST API. They have been noticed by many programmers all over the world, which led to abandoning SOAP architecture in favor of REST. The biggest advantage is undoubtedly the universality. As an example we can give here, for example, the need to create a website and an application for one company. Creating one API will allow both sources to use it. REST interfaces are very intuitive and comfortable to use. This makes integration easier and reduces the time it takes to analyze documentation. REST API also allows the use of information from several sources.
For example, the application can use logins from two different services. The interface also allows for the separation of the server layer from the client layer. An alternative may be to create views using template engines, however, it seems to be a more complicated and less popular solution. The last but not least advantage is the ability to test endpoints very easily.
REST API requirements
In conclusion, it is worth pointing out the conditions that are necessary for a REST API. It is not necessary to know them by heart, but understanding them will significantly speed up the programming process. The first of them is the need for the client to communicate with the server in order to access the service. Another one is the so-called uniform interface, i.e. there can be only one way to perform a particular action. Statelessness is also necessary. Each operation cannot change the result for another regardless of the previously performed actions. Data must also be buffered if the server cannot handle all requests in real time. Layer partitioning is also necessary. The client need not have access to the application. It can be separated by an authentication layer.
Working as a cyber security solutions architect, Alisa focuses on application and network security. Before joining us she held a cyber security researcher positions within a variety of cyber security start-ups. She also experience in different industry domains like finance, healthcare and consumer products.