A simple ruby on rails api

Rails is a Ruby web framework which includes everything you need to build fantastic applications, and you can learn it with the support of our large, friendly community.

Requirements

ruby on rails on your machine
A database server/ engine :sqlite, mariadb, postgres, etc
A code editor: I recommend Vim or VS Code
Internet connection

What makes a good API?

Predictable and consistent
Static
Simple and clear
Flexible: easy to scale and maintain

API versioning is mandatory only if:

You are introducing breaking changes features
Your clients apps are installable eg on mobile or desktop
If other developer will use your api
If you plan to scale you application
If you are shipping features gradually

Things to consider

Step 1: Open your terminal and type:

  rails new [your api name] - api

here make sure to leave space between the dash(-) and the api keyword In this exmple is used sqlite if you don't want to use sqlite a -d to spacify your database

Step 2: Versioning your api

We wanna access our api via /api/v1 url. First let's create the missing folders

    mkdir app/controllers/api
    mkdir app/controllers/api/v1

Step 3: Scaffold a resource

Open terminal and excute Rails commands

    rails g scaffold Articles title:string content:text slug:string

    rails db:migrate

Step 4: Move the resource controller to its respective folder

   mv app/controllers/articles_controller.rb app/controllers/api/v1

Step 5: Update the controller

We will add the namespaces prior (before) the class name (line 1) and update the url helper in the create method The final result should be something like this

class Api::V1::ArticlesController < ApplicationController

      before_action :set_article, only: [:show, :update, :destroy]
    
       # GET /articles
       def index
          @articles = Article.all
          render json: @articles
       end

       # GET /articles/1
       def show
           render json: @article
       end
     
       # POST /articles
       def create
           @article = Article.new(article_params)
           if @article.save
              render json: @article, status: :created, location:
              api_v1_article_url(@article)
           else
              render json: @article.errors, status: :unprocessable_entity
           end
       end
     
      # PATCH/PUT /articles/1
      def update
          if @article.update(article_params)
              render json: @article
          else
              render json: @article.errors, status: :unprocessable_entity
          end
      end
      
      # DELETE /articles/1
      def destroy
          @article.destroy
      end
     
     private
     # Use callbacks to share common setup or constraints
     between actions.
     def set_article
         @article = Article.find(params[:id])
     end
     
     # Only allow a trusted parameter “white list” through.
     def article_params
         params.require(:article).permit(:title, :content, :slug)
     end
   end

Step 6: Update the route file

Open config/routes.rb with your text editor. Delete the resource line

     resource :articles

Then add the namespaces. The final route file should look like the one below

      Rails.application.routes.draw do
           namespace :api do
               namespace :v1 do 
                  resources :articles
                end
            end
            # For details on the DSL available within this file, see
            http://guides.rubyonrails.org/routing.html
      end

Step 7: More resources

You can repeat the steps (3 - 6) for as many resources as you want

Step 8: Try it!

We will start by seeding the database Open db/seeds.rb and create a record

   Article.create(title: "Hello World", content: "This is my first api application in rails", slug: "hello-world")

Then run

  rails db:seed

Start the server

  rails s

Open the browser and go to

  http://localhost:3000/api/v1/articles

or you can use postman if you have installed it

CONGRATULATIONS!! YOU HAVE MADE IT TO THE END!!!

Williamug/simple_rails_api