Tutorial

Creating a CRUD API with Ruby on Rails and Making API Calls

Jeremy Duncan

Jeremy Duncan

— 3 min read
Creating a CRUD API with Ruby on Rails and Making API Calls

In this tutorial, we will create a simple API using Ruby on Rails that supports CRUD (Create, Read, Update, Delete) operations. We will also demonstrate how to make API calls to this Rails API and handle the data.

Prerequisites

Before we start, ensure you have the following installed:

  • Ruby
  • Rails
  • Postman (for testing API calls)

Step 1: Setting Up the Rails Project

First, create a new Rails project:

rails new blog_api
cd blog_api

Generate a scaffold for a simple resource, Post:

rails generate scaffold Post title:string content:text

Setting up database

  1. Ensure your database and credentials are configured in config/database.yml
  2. Create the database
rails db:create
  1. Run the migrations to create the database tables:
rails db:migrate

Step 2: Configuring Routes

In config/routes.rb, ensure the routes are set up for the posts resource:

Rails.application.routes.draw do
  resources :posts
end

Step 3: Modify the PostsController

Update your PostsController to skip CSRF verification for JSON format requests.

app/controllers/posts_controller.rb

class PostsController < ApplicationController
  # Add to controller
  protect_from_forgery unless: -> { request.format.json? }

end

Step 4: Testing the API

Start the Rails server:

rails s

Creating a Post

To create a post, make a POST request to http://localhost:3000/posts with the following JSON body:

{
  "post": {
    "title": "My First Post",
    "content": "This is the content of my first post."
  }
}

Reading Posts

To get a list of posts, make a GET request to http://localhost:3000/posts.

Updating a Post

To update a post, make a PUT request to http://localhost:3000/posts/1 with the following JSON body:

{
  "post": {
    "title": "Updated Post",
    "content": "This is the updated content."
  }
}

Deleting a Post

To delete a post, make a DELETE request to http://localhost:3000/posts/1.

Step 5: Making API Calls with Postman

Sending a GET Request

  1. Open Postman and create a new GET request.
  2. Enter the URL: http://localhost:3000/posts
  3. Click Send and you should see a list of posts.

Sending a POST Request

  1. Create a new POST request in Postman.
  2. Enter the URL: http://localhost:3000/posts
  3. Go to the Body tab and select raw and JSON.
  4. Click Send to create a new post.

Enter the JSON body:

{
  "post": {
    "title": "Another Post",
    "content": "This is another post."
  }
}

Sending a PUT Request

  1. Create a new PUT request in Postman.
  2. Enter the URL: http://localhost:3000/posts/1
  3. Go to the Body tab and select raw and JSON.
  4. Click Send to update the post.

Enter the JSON body:

{
  "post": {
    "title": "Updated Post Title",
    "content": "This is the updated content of the post."
  }
}

Sending a DELETE Request

  1. Create a new DELETE request in Postman.
  2. Enter the URL: http://localhost:3000/posts/1
  3. Click Send to delete the post.

Conclusion

In this tutorial, we created a simple CRUD API using Ruby on Rails and demonstrated how to make API calls using Postman. This setup provides a foundation for building more complex APIs and interacting with them programmatically.

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