A Quick Introduction to REST API

REST stands for Representational State Transfer. It is a software architectural style that defines a set of constraints or rules that you should adhere to when you are creating your APIs.

What about RESTful APIs? Well, when the APIs are conformed to these constraints, they are called RESTful APIs.

REST sets up a standard that makes it easier to use those APIs and anyone (ex: developer) familiar with these standards can quickly start using these APIs.

Let’s go over some of these architectural constraints:

  • Client — Server separation: Client (let’s say your browser) and server shouldn’t depend on each other, they should act independently and communication should only happen using request which only Client should be able to make. Server shouldn’t send the client information which hasn’t even been requested. So basically the main principle behind this is having the separation of concerns between Client and the Server.
  • Uniform interface: Client and Server should provide all the necessary info to each other so both can act upon the data accordingly, for example — request should contain resource identifier i.e the endpoint when making a request. There are also some other constraints for this,
  • Statelessness — Server should not store any info about the user using that API. So every time a request is made by the client, it will need to contain all the info required for the server to provide you with a proper response. Even if the request is made 100 times server wouldn’t remember that so its client’s responsibility to send all the relevant data to the server
  • Cacheability — Response provided by the server is cacheable or not (usually checked by version number)
  • Layered System — there could be many other layers (proxy or load-balancer) between client and servers but it shouldn’t affect the request or response in any way
  • Code on demand — Optional constraint, the server can provide executable code (scripts) to the client on demand

If you are interested, you can read more about these constraints  here

With REST most commonly used means of communication is via  HTTP. Let’s take a look at what the HTTP Request looks like -

  • Base URI: this is where you are making the request from. ex:  https://jsonplaceholder.typicode.com/todos/1
  • HTTP Methods: what operation you are performing (GET, POST etc…)
  • Headers: additional information passed to the client and server (ex: authentication, content-type etc…)
  • Body: optional data/body to provide with the request

We covered HTTP methods briefly above, let’s go over them a little bit more. REST HTTP Methods follow CRUD operations and it maps the following way:

  • POST (Create) — creates a new resource (adds a new entry in the database)
  • GET (Read) — most commonly used to fetch/retrieve data
  • PUT/PATCH (Update) — used to update a resource (edits an existing entry in the database)
  • DELETE (Delete) — delete a resource from the server (delete the entry from the database)

Check out the video below to see a real API example to better understand the above topics

#api #rest-api #what-is-rest-api #automation-testing

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A Quick Introduction to REST API
Wilford  Pagac

Wilford Pagac

1594289280

What is REST API? An Overview | Liquid Web

What is REST?

The REST acronym is defined as a “REpresentational State Transfer” and is designed to take advantage of existing HTTP protocols when used for Web APIs. It is very flexible in that it is not tied to resources or methods and has the ability to handle different calls and data formats. Because REST API is not constrained to an XML format like SOAP, it can return multiple other formats depending on what is needed. If a service adheres to this style, it is considered a “RESTful” application. REST allows components to access and manage functions within another application.

REST was initially defined in a dissertation by Roy Fielding’s twenty years ago. He proposed these standards as an alternative to SOAP (The Simple Object Access Protocol is a simple standard for accessing objects and exchanging structured messages within a distributed computing environment). REST (or RESTful) defines the general rules used to regulate the interactions between web apps utilizing the HTTP protocol for CRUD (create, retrieve, update, delete) operations.

What is an API?

An API (or Application Programming Interface) provides a method of interaction between two systems.

What is a RESTful API?

A RESTful API (or application program interface) uses HTTP requests to GET, PUT, POST, and DELETE data following the REST standards. This allows two pieces of software to communicate with each other. In essence, REST API is a set of remote calls using standard methods to return data in a specific format.

The systems that interact in this manner can be very different. Each app may use a unique programming language, operating system, database, etc. So, how do we create a system that can easily communicate and understand other apps?? This is where the Rest API is used as an interaction system.

When using a RESTful API, we should determine in advance what resources we want to expose to the outside world. Typically, the RESTful API service is implemented, keeping the following ideas in mind:

  • Format: There should be no restrictions on the data exchange format
  • Implementation: REST is based entirely on HTTP
  • Service Definition: Because REST is very flexible, API can be modified to ensure the application understands the request/response format.
  • The RESTful API focuses on resources and how efficiently you perform operations with it using HTTP.

The features of the REST API design style state:

  • Each entity must have a unique identifier.
  • Standard methods should be used to read and modify data.
  • It should provide support for different types of resources.
  • The interactions should be stateless.

For REST to fit this model, we must adhere to the following rules:

  • Client-Server Architecture: The interface is separate from the server-side data repository. This affords flexibility and the development of components independently of each other.
  • Detachment: The client connections are not stored on the server between requests.
  • Cacheability: It must be explicitly stated whether the client can store responses.
  • Multi-level: The API should work whether it interacts directly with a server or through an additional layer, like a load balancer.

#tutorials #api #application #application programming interface #crud #http #json #programming #protocols #representational state transfer #rest #rest api #rest api graphql #rest api json #rest api xml #restful #soap #xml #yaml

An API-First Approach For Designing Restful APIs | Hacker Noon

I’ve been working with Restful APIs for some time now and one thing that I love to do is to talk about APIs.

So, today I will show you how to build an API using the API-First approach and Design First with OpenAPI Specification.

First thing first, if you don’t know what’s an API-First approach means, it would be nice you stop reading this and check the blog post that I wrote to the Farfetchs blog where I explain everything that you need to know to start an API using API-First.

Preparing the ground

Before you get your hands dirty, let’s prepare the ground and understand the use case that will be developed.

Tools

If you desire to reproduce the examples that will be shown here, you will need some of those items below.

  • NodeJS
  • OpenAPI Specification
  • Text Editor (I’ll use VSCode)
  • Command Line

Use Case

To keep easy to understand, let’s use the Todo List App, it is a very common concept beyond the software development community.

#api #rest-api #openai #api-first-development #api-design #apis #restful-apis #restful-api

Adonis  Kerluke

Adonis Kerluke

1596509565

RESTful API Design Driven Approach

In this tutorial I will show you the fundamentals of designing a RESTful API specification by applying REST principles and best practices, then you’ll be ready to try my online tutorial: How to design a REST API with API Designer?

If you already know what is meant by API in the context of RESTful web services, you can skip to the next section. If not, read on.

Level-Set on API

The abbreviation API stands for Application Programming Interface this in itself, does not help us understand what it is, however in the context of web services, it can refer to one of two things:

  1. The RESTful API specification is written using a modeling language such as Open API specification or RAML (RESTful API Modeling Language) that defines a contract for how software components can interact with a service.
  2. The implementation of a web service or microservice whose contract is designed by REST principles that describe how other services must interact with it.

In this post, I will use the first understanding of this term. Even though both are correct, the most technically relevant for this post is the first: an API is a contract for how software applications talk to each other.

Level-Set on REST

The acronym REST stands for REpresentational State Transfer. It is an architectural style used to represent the transmission of data from one application component to another. In the context of web services, we are talking about the representation of resources (i.e. data) transferred over HTTP by calling a URI that represents the data and via an HTTP method that represents the action to perform against the given data.

What Is RESTful API design?

RESTful API design is the activity of describing the behavior of a web service in terms of its data structures and the actions you allow other application components to perform on its data by the principles of REST. Those principles are covered later in this blog.

Why Design a RESTful API?

Imagine that you are an Architect (the kind the design building) and you set out to build an office block without a blueprint. You turn up on the first day with a truck full of bricks and some cement. What are the chances that you’ll be successful and build a structure that conforms to code and more importantly, doesn’t fall? It’s about zero. Without a blueprint the chance of failure is high.

The same approach applies to web service development. You need a blueprint, or more appropriately, an API specification. This is necessary to evaluate the API design and solicit feedback before even starting to build the implementation.

In addition to providing a specification for the web service’s development, an API contract serves to document its expected behavior, data types, and security requirements.

You should now be satisfied that API design is necessary for a RESTful web service, and should start to wonder how is the best approach to actually designing an API specification.

API Design Tooling

The tooling chosen by an API designer has substantial influence over the designer’s productivity. Highly productive tools such as the Anypoint API Designer from MuleSoft is perfect for designing APIs with OAS (swagger) or RAML.

#integration #api #rest #rest api #restful #api design #raml #rest api design