REST (Representational State Transfer)

Intro

REST

REST is an architectural style specifically designed for building web services using standard HTTP methods (GET, POST, PUT, DELETE, etc.) and defined by key design principles:

• Statelessness: No session between the server and client; each request is independent.
• Uniform Interface: Resources are identified via URIs, and data formats are typically JSON or XML.
• Client-Server: Separation of client and server concerns.
• Cacheable: Responses must be explicitly marked as cacheable or not.

REST- Roy Fielding PhD Dissertation

The Representational State Transfer (REST) style is an abstraction of the architectural elements within a distributed hypermedia system. REST ignores the details of component implementation and protocol syntax in order to focus on the roles of components, the constraints upon their interaction with other components, and their interpretation of significant data elements. It encompasses the fundamental constraints upon components, connectors, and data that define the basis of the Web architecture, and thus the essence of its behavior as a network-based application

REST API Architecture

Rest API Queries

A REST API query typically involves sending an HTTP request to a specified endpoint (URL) with certain parameters, headers, and sometimes a body, depending on the type of request being made (GET, POST, PUT, DELETE, etc.).

A REST API query typically includes:

• An HTTP method (GET, POST, PUT, DELETE)
• A URL endpoint
• Request headers (like Content-Type or Accept)
• An optional request body (for POST and PUT requests)
• Query parameters (for filtering, searching, etc.)

This structure allows clients to communicate with the server and perform CRUD (Create, Read, Update, Delete) operations on resources effectively.

Here’s a breakdown of what a REST API query might look like for various types of requests:

1. GET Request

This is used to retrieve data from the server.

Example: Fetching a user profile

GET /api/users/123 HTTP/1.1
Host: example.com
Accept: application/json

Example URL:

https://example.com/api/users/123

2. POST Request

This is used to create a new resource on the server.

Example: Creating a new user

POST /api/users HTTP/1.1
Host: example.com
Content-Type: application/json
Accept: application/json
 
{
  "name": "Alice",
  "email": "alice@example.com"
}

3. PUT Request

This is used to update an existing resource.

Example: Updating user profile

PUT /api/users/123 HTTP/1.1
Host: example.com
Content-Type: application/json
Accept: application/json
 
{
  "name": "Alice Smith",
  "email": "alice.smith@example.com"
}

4. DELETE Request

This is used to delete a resource.

Example: Deleting a user

DELETE /api/users/123 HTTP/1.1
Host: example.com
Accept: application/json

Using a Query Parameter

For example, if you want to search for users by name, you might use a query parameter in a GET request.

Example: Searching users

GET /api/users?name=Alice HTTP/1.1
Host: example.com
Accept: application/json

Example Using Fetch in JavaScript

Here’s how you might make a GET request using the Fetch API in JavaScript:

fetch('https://example.com/api/users/123', {
  method: 'GET',
  headers: {
    'Accept': 'application/json'
  }
})
.then(response => response.json())
.then(data => console.log(data))
.catch(error => console.error('Error:', error));

RESTful APIs

A RESTful API is an application programming interface that conforms to the constraints of REST architecture.

• flask-restful-api-tutorials