Restful API Ruby on Rails

In this time I will create a simple Restful API with the Ruby on Rails framework.

Preparation

Use Postman for test your API
Use Rack CORS for handling Cross-Origin Resource Sharing (CORS), making cross-origin AJAX possible.

Installation Ruby on Rails

Because we only create a simple Restful API, so what we run is the following command to create a project Ruby on Rails.

rails new project-name --api -T

This means that we will create a project only for the API without unit tests.

Configure

Activate Rack CORS on Rails to get our API. The easiest way to configure CORS on your Rails app is to use rack-cors gem. You can install it like any other gem, by executing:

gem install rack-cors

or by adding the following line into your Gemfile:

gem 'rack-cors'

Next, you need to provide the configuration for the gem. You need to inform Rails which origin it should allow. To do that, you need to create a new initializer for your application.

The content of the config/initializers/cors.rb should be the following:

Rails.application.config.middleware.insert_before 0, Rack::Cors do
  allow do
    origins "https://examples.com" ## or '*' if the API used is only for localhost.

    resource "*",
      headers: :any,
      methods: [:get, :post, :put, :patch, :delete, :options, :head]
  end
end

Restful API as student example

create a model student with the attribute name, and address

rails generate model Student name: string address: text

create a students controller as follow

rails generate controller students

on the directory controller create a new directory as follows "api/v1" and move file student_controllers.rb to that directory. Next, change the command in the students_controller file to

module Api
  module V1
    class StudentsController < ApplicationController
      def index
        @students = Student.all
        render json: @students
      end

      def show
        @student = Student.find(params[:id])
        render json: @student
      end

      def create
        @student = Student.new(student_params)

        if @student.save
          render json: @student
        else
          render json: @student.errors, status: :unprocessable_entity
        end
      end

      def update
        @student = Student.find(params[:id])

        if @student.update(student_params)
          render json: @student
        else
          render json: @student, status: :unprocessable_entity
        end
      end

      def destroy
        @student = Student.find(params[:id])

        if @student.present?
          @student.destroy
          render json: @student
        else
          render json: { error: 'Student not found' }
        end
      end

      private
      def student_params
        params.require(:student).permit(:name, :address)
      end
    end
  end
end

Next, do API testing (GET, POST, PUT, DELETE) with Postman and check whether "localhost/api/v1/students" run well or not.

myusuf20 / restful-api-ruby-on-rails Goto Github PK