Rails API 💎
The new rails api command scaffolds everything we need to get up and running.
- Run the following:
rails new my-first-api --api -T
What’s going on here? The
--api command tells rails that we want an API structure application instead of a standard rails structure. The
-T command also tells rails that we don’t want Minitest as our testing suite. You’ll most likely be used to Rspec so we’ll talk about that later in the guide.
- Enable Cross-Origin Resource Sharing (CORS) in your gem and config directory. Locate your gemfile and uncomment the following
# Use Rack CORS for handling Cross-Origin Resource Sharing (CORS), making cross-origin AJAX possible gem 'rack-cors'
Do not forget to
bundle install !
Now in your config/initializers directory, you should now see a
cors.rb file. Add the following to
# config/initializers/cors.rb class Application < Rails::Application config.middleware.insert_before 0, "Rack::Cors" do allow do origins '*' resource '*', :headers => :any, :methods => [:get, :post, :patch, :options] end end end
Since this tutorial is mainly for testing and toy projects, we are allowing ALL methods from another domain. You should tailor the header and methods to your liking.
Rails API Versioning
Versioning is the process of seperating and creating new features/data/endpoints for your API. Since this is our first API, let’s make our
- Run the following in your terminal
mkdir mkdir app/controllers/api && mkdir app/controllers/api/v1
If everything looks right you should see your directory identical as below.
Now that our versioning is complete, let’s test out a model and controller to work with our new url of
- Let’s scaffold a test model/controller and call it
rails g scaffold Movies name:string rating:integer rails db:migrate
The Rails engine creates your controller in the default
/controllers directory but we need to move our new controller into the
- You can either move it manually or the following:
mv app/controllers/movies_controller.rb app/controllers/api/v1
- Update the Movies Controller
Our newly generated controller does not properly inherit from the namespace api/v1 (We will update the routes later in the tutorial) so let’s change our controller class from
class MoviesController < ApplicationController
class Api::V1::MoviesController < ApplicationController
- Update the Routes
Locate to your config folder and open your
Rails.application.routes.draw do resources :movies end
If we go to
localhost:3000/movies we will not call the controller. We must update our Routes to:
Rails.application.routes.draw do namespace :api do namespace :v1 do resources :movies end end end
which allows us to call the json data from
- Let’s seed our sqlite database with some classic movies so we can practice getting data with GET requests to the API.
Copy and paste the following data to your
Movie.create(name: "The Nightmare Before Christmas", rating: 5) Movie.create(name: "Titanic", rating: 5) Movie.create(name: "Venom", rating: 4) Movie.create(name: "A Quiet Place", rating: 5) Movie.create(name: "Nobody's Fool", rating: 2) Movie.create(name: "Suspiria", rating: 4) Movie.create(name: "Hereditary", rating: 4) Movie.create(name: "Office Space", rating: 5) Movie.create(name: "Elf", rating: 4) Movie.create(name: "Dawn of the Planet of the Apes", rating: 3) Movie.create(name: "Secret life of Pets", rating: 4) Movie.create(name: "Overlord", rating: 3) Movie.create(name: "Wonder Woman", rating: 5) Movie.create(name: "Bohemian Rhapsody", rating: 4) Movie.create(name: "Ocean's 8", rating: 5)
Seed the DB using
rails db:seed && rails db:migrate
- Test the API using a GET request.
Start your Rails server
rails s and navigate to
localhost:3000/api/v1/movies and if it is successful you should see the following JSON output:
(Optional) I’m using a pretty JSON viewer for chrome which you can download here.
Congrats! You have successfully created a Rails API and completed your first GET request!