How to Use REST APIs

How Do APIs Work and Why Do You Need Them?

APIs represent a set of definitions and protocols. You need them for app development and integration as they facilitate data exchange between two pieces of software, like an information supplier (a server) and a user. APIs specify the content available to the client making the call from the producer that's returning the response.

The reasons to integrate an API include:

• streamlining resource and information sharing.
• safety and control.
• no need to understand the software specifics.
• consistent communication between services, even though they use different technologies.

Overview of REST APIs

Representational State Transfer (REST) is an architectural style that defines a set of constraints to be used for creating web services. REST API is a way of accessing web services in a simple and flexible way without having any processing.

REST technology is generally preferred to the more robust Simple Object Access Protocol (SOAP) technology because REST uses less bandwidth, simple and flexible making it more suitable for internet usage. It’s used to fetch or give some information from a web service. All communication done via REST API uses only HTTP request.?

Below you will find some of the purposes of using REST APIs.

1. Web Use

There’s no specific client-side technology for REST as it suits diverse projects, such as:

• web development
• iOS apps
• IoT devices
• Windows Phone apps

As you won’t have to stick to a specific client-side stack, you can build any infrastructure for your company.

2. Applications in the Cloud

REST API calls are ideal for cloud applications due to their statelessness. If something goes wrong, you can re-deploy stateless components, and they can grow to manage traffic shifts.

3. Cloud Computing

An API connection to a service requires controlling how the URL is decoded. That’s why REST has become more useful in cloud services.

RESTful API architecture will become the norm in the future, thanks to cloud computing and microservices.

How do REST APIs Work?

A request is sent from client to server in the form of a web URL as HTTP GET or POST or PUT or DELETE request. After that, a response comes back from the server in the form of a resource which can be anything like HTML, XML, Image, or JSON. But now JSON is the most popular format being used in Web Services.?

In HTTP there are five methods that are commonly used in a REST-based Architecture i.e., POST, GET, PUT, PATCH, and DELETE. These correspond to create, read, update, and delete (or CRUD) operations respectively.

1. GET: The HTTP GET method is used to read (or retrieve) a representation of a resource. In the safe path, GET returns a representation in XML or JSON and an HTTP response code of 200 (OK). In an error case, it most often returns a 404 (NOT FOUND) or 400 (BAD REQUEST).?
2. POST: The POST verb is most often utilized to create new resources. On successful creation, return HTTP status 201, returning a Location header with a link to the newly-created resource with the 201 HTTP status.?
3. PUT: It is used for updating the capabilities. However, PUT can also be used to create a resource. On successful update, return 200 (or 204 if not returning any content in the body) from a PUT. If using PUT for create, return HTTP status 201 on successful creation. PUT is not safe operation but it’s idempotent.?
4. PATCH: It is used to modify capabilities. The PATCH request only needs to contain the changes to the resource, not the complete resource. This means that the PATCH body should not just be a modified part of the resource, but in some kind of patch language like JSON Patch or XML Patch. PATCH is neither safe nor idempotent.?
5. DELETE: It is used to delete a resource identified by a URI. On successful deletion, return HTTP status 200 (OK) along with a response body.?