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      How To Set Up a Ruby on Rails Project with a React Frontend


      The author selected the Electronic Frontier Foundation to receive a donation as part of the Write for DOnations program.

      Introduction

      Ruby on Rails is a popular server-side web application framework, with over 42,000 stars on GitHub at the time of writing this tutorial. It powers a lot of the popular applications that exist on the web today, like GitHub, Basecamp, SoundCloud, Airbnb, and Twitch. With its emphasis on programmer experience and the passionate community that has built up around it, Ruby on Rails will give you the tools you need to build and maintain your modern web application.

      React is a JavaScript library used to create front-end user interfaces. Backed by Facebook, it is one of the most popular front-end libraries used on the web today. React offers features like a virtual Document Object Model (DOM), component architecture, and state management, which make the process of front-end development more organized and efficient.

      With the frontend of the web moving toward frameworks that are separate from the server-side code, combining the elegance of Rails with the efficiency of React will let you build powerful and modern applications informed by current trends. By using React to render components from within a Rails view instead of the Rails template engine, your application will benefit from the latest advancements in JavaScript and front-end development while still leveraging the expressiveness of Ruby on Rails.

      In this tutorial, you will create a Ruby on Rails application that stores your favorite recipes then displays them with a React frontend. When you are finished, you will be able to create, view, and delete recipes using a React interface styled with Bootstrap:

      Completed Recipe App

      If you would like to take a look at the code for this application, check out the companion repository for this tutorial on the DigitalOcean Community GitHub.

      Prerequisites

      To follow this tutorial, you need to have the following:

      • Node.js and npm installed on your development machine. This tutorial uses Node.js version 10.16.0 and npm version 6.9.0. Node.js is a JavaScript run-time environment that allows you to run your code outside of the browser. It comes with a pre-installed Package Manager called npm, which lets you install and update packages. To install these on macOS or Ubuntu 18.04, follow the steps in How to Install Node.js and Create a Local Development Environment on macOS or the “Installing Using a PPA” section of How To Install Node.js on Ubuntu 18.04.

      • The Yarn package manager installed on your development machine, which will allow you to download the React framework. This tutorial was tested on version 1.16.0; to install this dependency, follow the official Yarn installation guide.

      • Installation of the Ruby on Rails framework. To get this, follow our guide on How to Install Ruby on Rails with rbenv on Ubuntu 18.04, or How To Install Ruby on Rails with rbenv on CentOS 7. If you would like to develop this application on macOS, please see this tutorial on How To Install Ruby on Rails with rbenv on macOS. This tutorial was tested on version 2.6.3 of Ruby and version 5.2.3 of Rails, so make sure to specify these versions during the installation process.

      • Installation of PostgreSQL, as shown in Steps 1 and 2 of our tutorial How To Use PostgreSQL with Your Ruby on Rails Application on Ubuntu 18.04 or How To Use PostgreSQL with Your Ruby on Rails Application on macOS. To follow this tutorial, use PostgreSQL version 10. If you are looking to develop this application on a different distribution of Linux or on another OS, see the official PostgreSQL downloads page. For more information on how to use PostgreSQL, see our How To Install and Use PostgreSQL tutorials.

      Step 1 — Creating a New Rails Application

      In this step, you will build your recipe application on the Rails application framework. First, you’ll create a new Rails application, which will be set up to work with React out of the box with little configuration.

      Rails provides a number of scripts called generators that help in creating everything that’s necessary to build a modern web application. To see a full list of these commands and what they do, run the following command in your Terminal window:

      This will yield a comprehensive list of options, which will allow you to set the parameters of your application. One of the commands listed is the new command, which creates a new Rails application.

      Now, you will create a new Rails application using the new generator. Run the following command in your Terminal window:

      • rails new rails_react_recipe -d=postgresql -T --webpack=react --skip-coffee

      The preceding command creates a new Rails application in a directory named rails_react_recipe, installs the required Ruby and JavaScript dependencies, and configures Webpack. Let’s walk through the flags that are associated with this new generator command:

      • The -d flag specifies the preferred database engine, which in this case is PostgreSQL.
      • The -T flag instructs Rails to skip the generation of test files, since you won’t be writing tests for the purposes of this tutorial. This command is also suggested if you want to use a Ruby testing tool different from the one Rails provides.
      • The --webpack instructs Rails to preconfigure for JavaScript with the webpack bundler, in this case specifically for a React application.
      • The --skip-coffee asks Rails not to set up CoffeeScript, which is not needed for this tutorial.

      Once the command is done running, move into the rails_react_recipe directory, which is the root directory of your app:

      Next, list out the contents of the directory:

      This root directory has a number of auto-generated files and folders that make up the structure of a Rails application, including a package.json file containing the dependencies for a React application.

      Now that you have successfully created a new Rails application, you are ready to hook it up to a database in the next step.

      Step 2 — Setting Up the Database

      Before you run your new Rails application, you have to first connect it to a database. In this step, you'll connect the newly created Rails application to a PostgreSQL database, so recipe data can be stored and fetched when needed.

      The database.yml file found in config/database.yml contains database details like database name for different development environments. Rails specifies a database name for the different development environments by appending an underscore (_) followed by the environment name to your app’s name. You can always change any environment database name to whatever you prefer.

      Note: At this point, you can alter config/database.yml to set up which PostgreSQL role you would like Rails to use to create your database. If you followed the Prerequisite How To Use PostgreSQL with Your Ruby on Rails Application and created a role that is secured by a password, you can follow the instructions in Step 4 for macOS or Ubuntu 18.04.

      As earlier stated, Rails offers a lot of commands to make developing web applications easy. This includes commands to work with databases, such as create, drop, and reset. To create a database for your application, run the following command in your Terminal window:

      This command creates a development and test database, yielding the following output:

      Output

      Created database 'rails_react_recipe_development' Created database 'rails_react_recipe_test'

      Now that the application is connected to a database, start the application by running the following command in you Terminal window:

      • rails s --binding=127.0.0.1

      The s or server command fires up Puma, which is a web server distributed with Rails by default, and --binding=127.0.0.1 binds the server to your localhost.

      Once you run this command, your command prompt will disappear, and you will see the following output:

      Output

      => Booting Puma => Rails 5.2.3 application starting in development => Run `rails server -h` for more startup options Puma starting in single mode... * Version 3.12.1 (ruby 2.6.3-p62), codename: Llamas in Pajamas * Min threads: 5, max threads: 5 * Environment: development * Listening on tcp://127.0.0.1:3000 Use Ctrl-C to stop

      To see your application, open a browser window and navigate to http://localhost:3000. You will see the Rails default welcome page:

      Rails welcome page

      This means that you have properly set up your Rails application.

      To stop the web server at anytime, press CTRL+C in the Terminal window where the server is running. Go ahead and do this now; you will get a goodbye message from Puma:

      Output

      ^C- Gracefully stopping, waiting for requests to finish === puma shutdown: 2019-07-31 14:21:24 -0400 === - Goodbye! Exiting

      Your prompt will then reappear.

      You have successfully set up a database for your food recipe application. In the next step, you will install all the extra JavaScript dependencies you need to put together your React frontend.

      Step 3 — Installing Frontend Dependencies

      In this step, you will install the JavaScript dependencies needed on the frontend of your food recipe application. They include:

      Run the following command in your Terminal window to install these packages with the Yarn package manager:

      • yarn add react-router-dom bootstrap jquery popper.js

      This command uses Yarn to install the specified packages and adds them to the package.json file. To verify this, take a look at the package.json file located in the root directory of the project:

      You'll see the installed packages listed under the dependencies key:

      ~/rails_react_recipe/package.json

      {
        "name": "rails_react_recipe",
        "private": true,
        "dependencies": {
          "@babel/preset-react": "^7.0.0",
          "@rails/webpacker": "^4.0.7",
          "babel-plugin-transform-react-remove-prop-types": "^0.4.24",
          "bootstrap": "^4.3.1",
          "jquery": "^3.4.1",
          "popper.js": "^1.15.0",
          "prop-types": "^15.7.2",
          "react": "^16.8.6",
          "react-dom": "^16.8.6",
          "react-router-dom": "^5.0.1"
        },
        "devDependencies": {
          "webpack-dev-server": "^3.7.2"
        }
      }
      

      You have installed a few front-end dependencies for your application. Next, you’ll set up a homepage for your food recipe application.

      Step 4 — Setting Up the Homepage

      With all the required dependencies installed, in this step you will create a homepage for the application. The homepage will serve as the landing page when users first visit the application.

      Rails follows the Model-View-Controller architectural pattern for applications. In the MVC pattern, a controller's purpose is to receive specific requests and pass them along to the appropriate model or view. Right now the application displays the Rails welcome page when the root URL is loaded in the browser. To change this, you will create a controller and view for the homepage and match it to a route.

      Rails provides a controller generator for creating a controller. The controller generator receives a controller name, along with a matching action. For more on this, check out the official Rails documentation.

      This tutorial will call the controller Homepage. Run the following command in your Terminal window to create a Homepage controller with an index action.

      • rails g controller Homepage index

      Note:
      On Linux, if you run into the error FATAL: Listen error: unable to monitor directories for changes., this is due to a system limit on the number of files your machine can monitor for changes. Run the following command to fix it:

      • echo fs.inotify.max_user_watches=524288 | sudo tee -a /etc/sysctl.conf && sudo sysctl -p

      This will permanently increase the amount of directories that you can monitor with Listen to 524288. You can change this again by running the same command and replacing 524288 with your desired number.

      Running this command generates the following files:

      • A homepage_controller.rb file for receiving all homepage-related requests. This file contains the index action you specified in the command.
      • A homepage.js file for adding any JavaScript behavior related to the Homepage controller.
      • A homepage.scss file for adding styles related to the Homepage controller.
      • A homepage_helper.rb file for adding helper methods related to the Homepage controller.
      • An index.html.erb file which is the view page for rendering anything related to the homepage.

      Apart from these new pages created by running the Rails command, Rails also updates your routes file which is located at config/routes.rb. It adds a get route for your homepage which you will modify as your root route.

      A root route in Rails specifies what will show up when users visit the root URL of your application. In this case, you want your users to see your homepage. Open the routes file located at config/routes.rb in your favorite editor:

      Inside this file, replace get 'homepage/index' with root 'homepage#index' so that the file looks like the following:

      ~/rails_react_recipe/config/routes.rb

      Rails.application.routes.draw do
        root 'homepage#index'
        # For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.html
      end
      

      This modification instructs Rails to map requests to the root of the application to the index action of the Homepage controller, which in turn renders whatever is in the index.html.erb file located at app/views/homepage/index.html.erb on to the browser.

      To verify that this is working, start your application:

      • rails s --binding=127.0.0.1

      Opening the application in the browser, you will see a new landing page for your application:

      Application Homepage

      Once you have verified that your application is working, press CTRL+C to stop the server.

      Next, delete the contents of the ~/rails_react_recipe/app/views/homepage/index.html.erb file. By doing this, you will ensure that the contents of index.html.erb do not interfere with the React rendering of your frontend.

      Now that you have set up your homepage for your application, you can move to the next section, where you will configure the frontend of your application to use React.

      Step 5 — Configuring React as Your Rails Frontend

      In this step, you will configure Rails to use React on the frontend of the application, instead of its template engine. This will allow you to take advantage of React rendering to create a more visually appealing homepage.

      Rails, with the help of the Webpacker gem, bundles all your JavaScript code into packs. These can be found in the packs directory at app/javascript/packs. You can link these packs in Rails views using the javascript_pack_tag helper, and you can link stylesheets imported into the packs using the stylesheet_pack_tag helper. To create an entry point to your React environment, you will add one of these packs to your application layout.

      First, rename the ~/rails_react_recipe/app/javascript/packs/hello_react.jsx file to ~/rails_react_recipe/app/javascript/packs/Index.jsx.

      • mv ~/rails_react_recipe/app/javascript/packs/hello_react.jsx ~/rails_react_recipe/app/javascript/packs/Index.jsx

      After renaming the file, open application.html.erb, the application layout file:

      • nano ~/rails_react_recipe/app/views/layouts/application.html.erb

      Add the following highlighted lines of code at the end of the head tag in the application layout file:

      ~/rails_react_recipe/app/views/layouts/application.html.erb

      <!DOCTYPE html>
      <html>
        <head>
          <title>RailsReactRecipe</title>
          <%= csrf_meta_tags %>
          <%= csp_meta_tag %>
      
          <%= stylesheet_link_tag    'application', media: 'all', 'data-turbolinks-track': 'reload' %>
          <%= javascript_include_tag 'application', 'data-turbolinks-track': 'reload' %>
          <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
          <%= javascript_pack_tag 'Index' %>
        </head>
      
        <body>
          <%= yield %>
        </body>
      </html>
      

      Adding the JavaScript pack to your application’s header makes all your JavaScript code available and executes the code in your Index.jsx file on the page whenever you run the app. Along with the JavaScript pack, you also added a meta viewport tag to control the dimensions and scaling of pages on your application.

      Save and exit the file.

      Now that your entry file is loaded onto the page, create a React component for your homepage. Start by creating a components directory in the app/javascript directory:

      • mkdir ~/rails_react_recipe/app/javascript/components

      The components directory will house the component for the homepage, along with other React components in the application. The homepage will contain some text and a call to action button to view all recipes.

      In your editor, create a Home.jsx file in the components directory:

      • nano ~/rails_react_recipe/app/javascript/components/Home.jsx

      Add the following code to the file:

      ~/rails_react_recipe/app/javascript/components/Home.jsx

      import React from "react";
      import { Link } from "react-router-dom";
      
      export default () => (
        <div className="vw-100 vh-100 primary-color d-flex align-items-center justify-content-center">
          <div className="jumbotron jumbotron-fluid bg-transparent">
            <div className="container secondary-color">
              <h1 className="display-4">Food Recipes</h1>
              <p className="lead">
                A curated list of recipes for the best homemade meal and delicacies.
              </p>
              <hr className="my-4" />
              <Link
                to="/recipes"
                className="btn btn-lg custom-button"
                role="button"
              >
                View Recipes
              </Link>
            </div>
          </div>
        </div>
      );
      

      In this code, you imported React and also the Link component from React Router. The Link component creates a hyperlink to navigate from one page to another. You then created and exported a functional component containing some Markup language for your homepage, styled with Bootstrap classes.

      With your Home component in place, you will now set up routing using React Router. Create a routes directory in the app/javascript directory:

      • mkdir ~/rails_react_recipe/app/javascript/routes

      The routes directory will contain a few routes with their corresponding components. Whenever any specified route is loaded, it will render its corresponding component to the browser.

      In the routes directory, create an Index.jsx file:

      • nano ~/rails_react_recipe/app/javascript/routes/Index.jsx

      Add the following code to it:

      ~/rails_react_recipe/app/javascript/routes/Index.jsx

      import React from "react";
      import { BrowserRouter as Router, Route, Switch } from "react-router-dom";
      import Home from "../components/Home";
      
      export default (
        <Router>
          <Switch>
            <Route path="/" exact component={Home} />
          </Switch>
        </Router>
      );
      

      In this Index.jsx route file, you imported a couple of modules: the React module that allows us to use React, and the BrowserRouter, Route, and Switch modules from React Router, which together help us navigate from one route to another. Lastly, you imported your Home component, which will be rendered whenever a request matches the root (/) route. Whenever you want to add more pages to your application, all you need to do is declare a route in this file and match it to the component you want to render for that page.

      Save and exit the file.

      You have now successfully set up routing using React Router. For React to be aware of the available routes and use them, the routes have to be available at the entry point to the application. To achieve this, you will render your routes in a component that React will render in your entry file.

      Create an App.jsx file in the app/javascript/components directory:

      • nano ~/rails_react_recipe/app/javascript/components/App.jsx

      Add the following code into the App.jsx file:

      ~/rails_react_recipe/app/javascript/components/App.jsx

      import React from "react";
      import Routes from "../routes/Index";
      
      export default props => <>{Routes}</>;
      

      In the App.jsx file, you imported React and the route files you just created. You then exported a component that renders the routes within fragments. This component will be rendered at the entry point of the aplication, thereby making the routes available whenever the application is loaded.

      Now that you have your App.jsx set up, it's time to render it in your entry file. Open the entry Index.jsx file:

      • nano ~/rails_react_recipe/app/javascript/packs/Index.jsx

      Replace the code there with the following code:

      ~/rails_react_recipe/app/javascript/packs/Index.jsx

      import React from "react";
      import { render } from "react-dom";
      import 'bootstrap/dist/css/bootstrap.min.css';
      import $ from 'jquery';
      import Popper from 'popper.js';
      import 'bootstrap/dist/js/bootstrap.bundle.min';
      import App from "../components/App";
      
      document.addEventListener("DOMContentLoaded", () => {
        render(
          <App />,
          document.body.appendChild(document.createElement("div"))
        );
      });
      

      In this code snippet, you imported React, the render method from ReactDOM, Bootstrap, jQuery, Popper.js, and your App component. Using ReactDOM's render method, you rendered your App component in a div element, which was appended to the body of the page. Whenever the application is loaded, React will render the content of the App component inside the div element on the page.

      Save and exit the file.

      Finally, add some CSS styles to your homepage.

      Open up your application.css in your ~/rails_react_recipe/app/assets/stylesheets directory:

      • nano ~/rails_react_recipe/app/assets/stylesheets/application.css

      Next, replace the contents of the application.css file with the follow code:

      ~/rails_react_recipe/app/assets/stylesheets/application.css

      .bg_primary-color {
        background-color: #FFFFFF;
      }
      .primary-color {
        background-color: #FFFFFF;
      }
      .bg_secondary-color {
        background-color: #293241;
      }
      .secondary-color {
        color: #293241;
      }
      .custom-button.btn {
        background-color: #293241;
        color: #FFF;
        border: none;
      }
      .custom-button.btn:hover {
        color: #FFF !important;
        border: none;
      }
      .hero {
        width: 100vw;
        height: 50vh;
      }
      .hero img {
        object-fit: cover;
        object-position: top;
        height: 100%;
        width: 100%;
      }
      .overlay {
        height: 100%;
        width: 100%;
        opacity: 0.4;
      }
      

      This creates the framework for a hero image, or a large web banner on the front page of your website, that you will add later. Additionally, this styles the button that the user will use to enter the application.

      With your CSS styles in place, save and exit the file. Next, restart the web server for your application, then reload the application in your browser. You will see a brand new homepage:

      Homepage Style

      In this step, you configured your application so that it uses React as its frontend. In the next section, you will create models and controllers that will allow you to create, read, update, and delete recipes.

      Step 6 — Creating the Recipe Controller and Model

      Now that you have set up a React frontend for your application, in this step you'll create a Recipe model and controller. The recipe model will represent the database table that will hold information about the user's recipes while the controller will receive and handle requests to create, read, update, or delete recipes. When a user requests a recipe, the recipe controller receives this request and passes it to the recipe model, which retrieves the requested data from the database. The model then returns the recipe data as a response to the controller. Finally, this information is displayed in the browser.

      Start by creating a Recipe model by using the generate model subcommand provided by Rails and by specifying the name of the model along with its columns and data types. Run the following command in your Terminal window to create a Recipe model:

      • rails generate model Recipe name:string ingredients:text instruction:text image:string

      The preceding command instructs Rails to create a Recipe model together with a name column of type string, an ingredients and instruction column of type text, and an image column of type string. This tutorial has named the model Recipe, because by convention models in Rails use a singular name while their corresponding database tables use a plural name.

      Running the generate model command creates two files:

      • A recipe.rb file that holds all the model related logic.
      • A 20190407161357_create_recipes.rb file (the number at the beginning of the file may differ depending on the date when you run the command). This is a migration file that contains the instruction for creating the database structure.

      Next, edit the recipe model file to ensure that only valid data is saved to the database. You can achieve this by adding some database validation to your model. Open your recipe model located at app/models/recipe.rb:

      • nano ~/rails_react_recipe/app/models/recipe.rb

      Add the following highlighted lines of code to the file:

      class Recipe < ApplicationRecord
        validates :name, presence: true
        validates :ingredients, presence: true
        validates :instruction, presence: true
      end
      

      In this code, you added model validation which checks for the presence of a name, ingredients, and instruction field. Without the presence of these three fields, a recipe is invalid and won’t be saved to the database.

      Save and quit the file.

      For Rails to create the recipes table in your database, you have to run a migration, which in Rails is a way to make changes to your database programmatically. To make sure that the migration works with the database you set up, it is necessary to make changes to the 20190407161357_create_recipes.rb file.

      Open this file in your editor:

      • nano ~/rails_react_recipe/db/migrate/20190407161357_create_recipes.rb

      Add the following highlighted lines, so that the file looks like this:

      db/migrate/20190407161357_create_recipes.rb

      class CreateRecipes < ActiveRecord::Migration[5.2]
        def change
          create_table :recipes do |t|
            t.string :name, null: false
            t.text :ingredients, null: false
            t.text :instruction, null: false
            t.string :image, default: 'https://raw.githubusercontent.com/do-community/react_rails_recipe/master/app/assets/images/Sammy_Meal.jpg'
            t.timestamps
          end
        end
      end
      

      This migration file contains a Ruby class with a change method, and a command to create a table called recipes along with the columns and their data types. You also updated 20190407161357_create_recipes.rb with a NOT NULL constraint on the name, ingredients, and instruction columns by adding null: false, ensuring that these columns have a value before changing the database. Finally, you added a default image URL for your image column; this could be another URL if you wanted to use a different image.

      With these changes, save and exit the file. You’re now ready to run your migration and actually create your table. In your Terminal window, run the following command:

      Here you used the database migrate command, which executes the instructions in your migration file. Once the command runs successfully, you will receive an output similar to the following:

      Output

      == 20190407161357 CreateRecipes: migrating ==================================== -- create_table(:recipes) -> 0.0140s == 20190407161357 CreateRecipes: migrated (0.0141s) ===========================

      With your recipe model in place, create your recipes controller and add the logic for creating, reading, and deleting recipes. In your Terminal window, run the following command:

      • rails generate controller api/v1/Recipes index create show destroy -j=false -y=false --skip-template-engine --no-helper

      In this command, you created a Recipes controller in an api/v1 directory with an index, create, show, and destroy action. The index action will handle fetching all your recipes, the create action will be responsible for creating new recipes, the show action will fetch a single recipe, and the destroy action will hold the logic for deleting a recipe.

      You also passed some flags to make the controller more lightweight, including:

      • -j=false which instructs Rails to skip generating associated JavaScript files.
      • -y=false which instructs Rails to skip generating associated stylesheet files.
      • --skip-template-engine, which instructs Rails to skip generating Rails view files, since React is handling your front-end needs.
      • --no-helper, which instructs Rails to skip generating a helper file for your controller.

      Running the command also updated your routes file with a route for each action in the Recipes controller. To use these routes, make changes to your config/routes.rb file.

      Open up the routes file in your text editor:

      • nano ~/rails_react_recipe/config/routes.rb

      Once it is open, update it to look like the following code, altering or adding the highlighted lines:

      ~/rails_react_recipe/config/routes.rb

      Rails.application.routes.draw do
        namespace :api do
          namespace :v1 do
            get 'recipes/index'
            post 'recipes/create'
            get '/show/:id', to: 'recipes#show'
            delete '/destroy/:id', to: 'recipes#destroy'
          end
        end
        root 'homepage#index'
        get '/*path' => 'homepage#index'
        # For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.html
      end
      

      In this route file, you modified the HTTP verb of the create and destroy routes so that it can post and delete data. You also modified the routes for the show and destroy action by adding an :id parameter into the route. :id will hold the identification number of the recipe you want to read or delete.

      You also added a catch all route with get '/*path' that will direct any other request that doesn’t match the existing routes to the index action of the homepage controller. This way, the routing on the frontend will handle requests that are not related to creating, reading, or deleting recipes.

      Save and exit the file.

      To see a list of routes available in your application, run the following command in your Terminal window:

      Running this command displays a list of URI patterns, verbs, and matching controllers or actions for your project.

      Next, add the logic for getting all recipes at once. Rails uses the ActiveRecord library to handle database-related tasks like this. ActiveRecord connects classes to relational database tables and provides a rich API for working with them.

      To get all recipes, you'll use ActiveRecord to query the recipes table and fetch all the recipes that exist in the database.

      Open the recipes_controller.rb file with the following command:

      • nano ~/rails_react_recipe/app/controllers/api/v1/recipes_controller.rb

      Add the following highlighted lines of code to the recipes controller:

      ~/rails_react_recipe/app/controllers/api/v1/recipes_controller.rb

      class Api::V1::RecipesController < ApplicationController
        def index
          recipe = Recipe.all.order(created_at: :desc)
          render json: recipe
        end
      
        def create
        end
      
        def show
        end
      
        def destroy
        end
      end
      

      In your index action, using the all method provided by ActiveRecord, you get all the recipes in your database. Using the order method, you order them in descending order by their created date. This way, you have the newest recipes first. Lastly, you send your list of recipes as a JSON response with render.

      Next, add the logic for creating new recipes. As with fetching all recipes, you'll rely on ActiveRecord to validate and save the provided recipe details. Update your recipe controller with the following highlighted lines of code:

      ~/rails_react_recipe/app/controllers/api/v1/recipes_controller.rb

      class Api::V1::RecipesController < ApplicationController
        def index
          recipe = Recipe.all.order(created_at: :desc)
          render json: recipe
        end
      
        def create
          recipe = Recipe.create!(recipe_params)
          if recipe
            render json: recipe
          else
            render json: recipe.errors
          end
        end
      
        def show
        end
      
        def destroy
        end
      
        private
      
        def recipe_params
          params.permit(:name, :image, :ingredients, :instruction)
        end
      end
      

      In the create action, you use ActiveRecord’s create method to create a new recipe. The create method has the ability to assign all controller parameters provided into the model at once. This makes it easy to create records, but also opens the possibility of malicious use. This can be prevented by using a feature provided by Rails known as strong parameters. This way, parameters can’t be assigned unless they’ve been whitelisted. In your code, you passed a recipe_params parameter to the create method. The recipe_params is a private method where you whitelisted your controller parameters to prevent wrong or malicious content from getting into your database. In this case, you are permitting a name, image, ingredients, and instruction parameter for valid use of the create method.

      Your recipe controller can now read and create recipes. All that’s left is the logic for reading and deleting a single recipe. Update your recipes controller with the following code:

      ~/rails_react_recipe/app/controllers/api/v1/recipes_controller.rb

      class Api::V1::RecipesController < ApplicationController
        def index
          recipe = Recipe.all.order(created_at: :desc)
          render json: recipe
        end
      
        def create
          recipe = Recipe.create!(recipe_params)
          if recipe
            render json: recipe
          else
            render json: recipe.errors
          end
        end
      
        def show
          if recipe
            render json: recipe
          else
            render json: recipe.errors
          end
        end
      
        def destroy
          recipe&.destroy
          render json: { message: 'Recipe deleted!' }
        end
      
        private
      
        def recipe_params
          params.permit(:name, :image, :ingredients, :instruction)
        end
      
        def recipe
          @recipe ||= Recipe.find(params[:id])
        end
      end
      

      In the new lines of code, you created a private recipe method. The recipe method uses ActiveRecord’s find method to find a recipe whose idmatches the id provided in the params and assigns it to an instance variable @recipe. In the show action, you checked if a recipe is returned by the recipe method and sent it as a JSON response, or sent an error if it was not.

      In the destroy action, you did something similar using Ruby’s safe navigation operator &., which avoids nil errors when calling a method. This let's you delete a recipe only if it exists, then send a message as a response.

      Now that you have finished making these changes to recipes_controller.rb, save the file and exit your text editor.

      In this step, you created a model and controller for your recipes. You’ve written all the logic needed to work with recipes on the backend. In the next section, you'll create components to view your recipes.

      Step 7 — Viewing Recipes

      In this section, you will create components for viewing recipes. First you’ll create a page where you can view all existing recipes, and then another to view individual recipes.

      You’ll start off by creating a page to view all recipes. However, before you can do this, you need recipes to work with, since your database is currently empty. Rails affords us the opportunity to create seed data for your application.

      Open up the seed file seeds.rb to edit:

      • nano ~/rails_react_recipe/db/seeds.rb

      Replace the contents of this seed file with the following code:

      ~/rails_react_recipe/db/seeds.rb

      9.times do |i|
        Recipe.create(
          name: "Recipe #{i + 1}",
          ingredients: '227g tub clotted cream, 25g butter, 1 tsp cornflour,100g parmesan, grated nutmeg, 250g fresh fettuccine or tagliatelle, snipped chives or chopped parsley to serve (optional)',
          instruction: 'In a medium saucepan, stir the clotted cream, butter, and cornflour over a low-ish heat and bring to a low simmer. Turn off the heat and keep warm.'
        )
      end
      

      In this code, you are using a loop to instruct Rails to create nine recipes with a name, ingredients, and instruction. Save and exit the file.

      To seed the database with this data, run the following command in your Terminal window:

      Running this command adds nine recipes to your database. Now you can fetch them and render them on the frontend.

      The component to view all recipes will make a HTTP request to the index action in the RecipesController to get a list of all recipes. These recipes will then be displayed in cards on the page.

      Create a Recipes.jsx file in the app/javascript/components directory:

      • nano ~/rails_react_recipe/app/javascript/components/Recipes.jsx

      Once the file is open, import the React and Link modules into it by adding the following lines:

      ~/rails_react_recipe/app/javascript/components/Recipes.jsx

      import React from "react";
      import { Link } from "react-router-dom";
      

      Next, create a Recipes class that extends the React.Component class. Add the following highlighted code to create a React component that extends React.Component:

      ~/rails_react_recipe/app/javascript/components/Recipes.jsx

      import React from "react";
      import { Link } from "react-router-dom";
      
      class Recipes extends React.Component {
        constructor(props) {
          super(props);
          this.state = {
            recipes: []
          };
        }
      
      }
      export default Recipes;
      

      Inside the constructor, we are initializing a state object that holds the state of your recipes, which on initialization is an empty array ([]).

      Next, add a componentDidMount method in the Recipe class. The componentDidMount method is a React lifecycle method that is called immediately after a component is mounted. In this lifecycle method, you will make a call to fetch all your recipes. To do this, add the following lines:

      ~/rails_react_recipe/app/javascript/components/Recipes.jsx

      import React from "react";
      import { Link } from "react-router-dom";
      
      class Recipes extends React.Component {
        constructor(props) {
          super(props);
          this.state = {
            recipes: []
          };
        }
      
        componentDidMount() {
            const url = "/api/v1/recipes/index";
            fetch(url)
              .then(response => {
                if (response.ok) {
                  return response.json();
                }
                throw new Error("Network response was not ok.");
              })
              .then(response => this.setState({ recipes: response }))
              .catch(() => this.props.history.push("/"));
        }
      
      }
      export default Recipes;
      

      In your componentDidMount method, you made an HTTP call to fetch all recipes using the Fetch API. If the response is successful, the application saves the array of recipes to the recipe state. If there’s an error, it will redirect the user to the homepage.

      Finally, add a render method in the Recipe class. The render method holds the React elements that will be evaluated and displayed on the browser page when a component is rendered. In this case, the render method will render cards of recipes from the component state. Add the following highlighted lines to Recipes.jsx:

      ~/rails_react_recipe/app/javascript/components/Recipes.jsx

      import React from "react";
      import { Link } from "react-router-dom";
      
      class Recipes extends React.Component {
        constructor(props) {
          super(props);
          this.state = {
            recipes: []
          };
        }
      
        componentDidMount() {
          const url = "/api/v1/recipes/index";
          fetch(url)
            .then(response => {
              if (response.ok) {
                return response.json();
              }
              throw new Error("Network response was not ok.");
            })
            .then(response => this.setState({ recipes: response }))
            .catch(() => this.props.history.push("/"));
        }
        render() {
          const { recipes } = this.state;
          const allRecipes = recipes.map((recipe, index) => (
            <div key={index} className="col-md-6 col-lg-4">
              <div className="card mb-4">
                <img
                  src={recipe.image}
                  className="card-img-top"
                  alt={`${recipe.name} image`}
                />
                <div className="card-body">
                  <h5 className="card-title">{recipe.name}</h5>
                  <Link to={`/recipe/${recipe.id}`} className="btn custom-button">
                    View Recipe
                  </Link>
                </div>
              </div>
            </div>
          ));
          const noRecipe = (
            <div className="vw-100 vh-50 d-flex align-items-center justify-content-center">
              <h4>
                No recipes yet. Why not <Link to="/new_recipe">create one</Link>
              </h4>
            </div>
          );
      
          return (
            <>
              <section className="jumbotron jumbotron-fluid text-center">
                <div className="container py-5">
                  <h1 className="display-4">Recipes for every occasion</h1>
                  <p className="lead text-muted">
                    We’ve pulled together our most popular recipes, our latest
                    additions, and our editor’s picks, so there’s sure to be something
                    tempting for you to try.
                  </p>
                </div>
              </section>
              <div className="py-5">
                <main className="container">
                  <div className="text-right mb-3">
                    <Link to="/recipe" className="btn custom-button">
                      Create New Recipe
                    </Link>
                  </div>
                  <div className="row">
                    {recipes.length > 0 ? allRecipes : noRecipe}
                  </div>
                  <Link to="/" className="btn btn-link">
                    Home
                  </Link>
                </main>
              </div>
            </>
          );
        }
      }
      export default Recipes;
      

      Save and exit Recipes.jsx.

      Now that you have created a component to display all the recipes, the next step is to create a route for it. Open the front-end route file located at app/javascript/routes/Index.jsx:

      • nano app/javascript/routes/Index.jsx

      Add the following highlighted lines to the file:

      ~/rails_react_recipe/app/javascript/routes/Index.jsx

      import React from "react";
      import { BrowserRouter as Router, Route, Switch } from "react-router-dom";
      import Home from "../components/Home";
      import Recipes from "../components/Recipes";
      
      export default (
        <Router>
          <Switch>
            <Route path="/" exact component={Home} />
            <Route path="/recipes" exact component={Recipes} />
          </Switch>
        </Router>
      );
      

      Save and exit the file.

      At this point, it's a good idea to verify that your code is working correctly. As you did before, use the following command to start your server:

      • rails s --binding=127.0.0.1

      Go ahead and open the app in your browser. By clicking the View Recipe button on the homepage, you will see a display with your seed recipes:

      Recipes Page

      Use CTRL+C in your Terminal window to stop the server and get your prompt back.

      Now that you can view all the recipes that exist in your application, it's time to create a second component to view individual recipes. Create a Recipe.jsx file in the app/javascript/components directory:

      • nano app/javascript/components/Recipe.jsx

      As with the Recipes component, import the React and Link modules by adding the following lines:

      ~/rails_react_recipe/app/javascript/components/Recipe.jsx

      import React from "react";
      import { Link } from "react-router-dom";
      

      Next create a Recipe class that extends React.Component class by adding the highlighted lines of code:

      ~/rails_react_recipe/app/javascript/components/Recipe.jsx

      import React from "react";
      import { Link } from "react-router-dom";
      
      class Recipe extends React.Component {
        constructor(props) {
          super(props);
          this.state = { recipe: { ingredients: "" } };
      
          this.addHtmlEntities = this.addHtmlEntities.bind(this);
        }
      }
      
      export default Recipe;
      

      Like with your Recipes component, in the constructor, you initialized a state object that holds the state of a recipe. You also bound an addHtmlEntities method to this so it can be accessible within the component. The addHtmlEntities method will be used to replace character entities with HTML entities in the component.

      In order to find a particular recipe, your application needs the id of the recipe. This means your Recipe component expects an id param. You can access this via the props passed into the component.

      Next, add a componentDidMount method where you will access the id param from the match key of the props object. Once you get the id, you will then make an HTTP request to fetch the recipe. Add the following highlighted lines to your file:

      ~/rails_react_recipe/app/javascript/components/Recipe.jsx

      import React from "react";
      import { Link } from "react-router-dom";
      
      class Recipe extends React.Component {
        constructor(props) {
          super(props);
          this.state = { recipe: { ingredients: "" } };
      
          this.addHtmlEntities = this.addHtmlEntities.bind(this);
        }
      
        componentDidMount() {
          const {
            match: {
              params: { id }
            }
          } = this.props;
      
          const url = `/api/v1/show/${id}`;
      
          fetch(url)
            .then(response => {
              if (response.ok) {
                return response.json();
              }
              throw new Error("Network response was not ok.");
            })
            .then(response => this.setState({ recipe: response }))
            .catch(() => this.props.history.push("/recipes"));
        }
      
      }
      
      export default Recipe;
      

      In the componentDidMount method, using object destructuring, you get the id param from the props object, then using the Fetch API, you make a HTTP request to fetch the recipe that owns the id and save it to the component state using the setState method. If the recipe does not exist, the app redirects the user to the recipes page.

      Now add the addHtmlEntities method, which takes a string and replaces all escaped opening and closing brackets with their HTML entities. This will help us convert whatever escaped character was saved in your recipe instruction:

      ~/rails_react_recipe/app/javascript/components/Recipe.jsx

      import React from "react";
      import { Link } from "react-router-dom";
      
      class Recipe extends React.Component {
        constructor(props) {
          super(props);
          this.state = { recipe: { ingredients: "" } };
      
          this.addHtmlEntities = this.addHtmlEntities.bind(this);
        }
      
        componentDidMount() {
          const {
            match: {
              params: { id }
            }
          } = this.props;
      
          const url = `/api/v1/show/${id}`;
      
          fetch(url)
            .then(response => {
              if (response.ok) {
                return response.json();
              }
              throw new Error("Network response was not ok.");
            })
            .then(response => this.setState({ recipe: response }))
            .catch(() => this.props.history.push("/recipes"));
        }
      
        addHtmlEntities(str) {
          return String(str)
            .replace(/&lt;/g, "<")
            .replace(/&gt;/g, ">");
        }
      }
      
      export default Recipe;
      

      Finally, add a render method that gets the recipe from the state and renders it on the page. To do this, add the following highlighted lines:

      ~/rails_react_recipe/app/javascript/components/Recipe.jsx

      import React from "react";
      import { Link } from "react-router-dom";
      
      class Recipe extends React.Component {
        constructor(props) {
          super(props);
          this.state = { recipe: { ingredients: "" } };
      
          this.addHtmlEntities = this.addHtmlEntities.bind(this);
        }
      
        componentDidMount() {
          const {
            match: {
              params: { id }
            }
          } = this.props;
      
          const url = `/api/v1/show/${id}`;
      
          fetch(url)
            .then(response => {
              if (response.ok) {
                return response.json();
              }
              throw new Error("Network response was not ok.");
            })
            .then(response => this.setState({ recipe: response }))
            .catch(() => this.props.history.push("/recipes"));
        }
      
        addHtmlEntities(str) {
          return String(str)
            .replace(/&lt;/g, "<")
            .replace(/&gt;/g, ">");
        }
      
        render() {
          const { recipe } = this.state;
          let ingredientList = "No ingredients available";
      
          if (recipe.ingredients.length > 0) {
            ingredientList = recipe.ingredients
              .split(",")
              .map((ingredient, index) => (
                <li key={index} className="list-group-item">
                  {ingredient}
                </li>
              ));
          }
          const recipeInstruction = this.addHtmlEntities(recipe.instruction);
      
          return (
            <div className="">
              <div className="hero position-relative d-flex align-items-center justify-content-center">
                <img
                  src={recipe.image}
                  alt={`${recipe.name} image`}
                  className="img-fluid position-absolute"
                />
                <div className="overlay bg-dark position-absolute" />
                <h1 className="display-4 position-relative text-white">
                  {recipe.name}
                </h1>
              </div>
              <div className="container py-5">
                <div className="row">
                  <div className="col-sm-12 col-lg-3">
                    <ul className="list-group">
                      <h5 className="mb-2">Ingredients</h5>
                      {ingredientList}
                    </ul>
                  </div>
                  <div className="col-sm-12 col-lg-7">
                    <h5 className="mb-2">Preparation Instructions</h5>
                    <div
                      dangerouslySetInnerHTML={{
                        __html: `${recipeInstruction}`
                      }}
                    />
                  </div>
                  <div className="col-sm-12 col-lg-2">
                    <button type="button" className="btn btn-danger">
                      Delete Recipe
                    </button>
                  </div>
                </div>
                <Link to="/recipes" className="btn btn-link">
                  Back to recipes
                </Link>
              </div>
            </div>
          );
        }
      
      }
      
      export default Recipe;
      

      In this render method, you split your comma separated ingredients into an array and mapped over it, creating a list of ingredients. If there are no ingredients, the app displays a message that says No ingredients available. It also displays the recipe image as a hero image, adds a delete recipe button next to the recipe instruction, and adds a button that links back to the recipes page.

      Save and exit the file.

      To view the Recipe component on a page, add it to your routes file. Open your route file to edit:

      • nano app/javascript/routes/Index.jsx

      Now, add the following highlighted lines to the file:

      ~/rails_react_recipe/app/javascript/routes/Index.jsx

      import React from "react";
      import { BrowserRouter as Router, Route, Switch } from "react-router-dom";
      import Home from "../components/Home";
      import Recipes from "../components/Recipes";
      import Recipe from "../components/Recipe";
      
      export default (
        <Router>
          <Switch>
            <Route path="/" exact component={Home} />
            <Route path="/recipes" exact component={Recipes} />
            <Route path="/recipe/:id" exact component={Recipe} />
          </Switch>
        </Router>
      );
      

      In this route file, you imported your Recipe component and added a route for it. Its route has an :id param that will be replaced by the id of the recipe you want to view.

      Use the rails s command to start your server again, then visit http://localhost:3000 in your browser. Click the View Recipes button to navigate to the recipes page. On the recipes page, view any recipe by clicking its View Recipe button. You will be greeted with a page populated with the data from your database:

      Single Recipe Page

      In this section, you added nine recipes to your database and created components to view these recipes, both individually and as a collection. In the next section, you will add a component to create recipes.

      Step 8 — Creating Recipes

      The next step to having a usable food recipe application is the ability to create new recipes. In this step, you will create a component for creating recipes. This component will contain a form for collecting the required recipe details from the user and will make a request to the create action in the Recipe controller to save the recipe data.

      Create a NewRecipe.jsx file in the app/javascript/components directory:

      • nano app/javascript/components/NewRecipe.jsx

      In the new file, import the React and Link modules you have used so far in other components:

      ~/rails_react_recipe/app/javascript/components/NewRecipe.jsx

      import React from "react";
      import { Link } from "react-router-dom";
      

      Next create a NewRecipe class that extends React.Component class. Add the following highlighted code to create a React component that extends react.Component:

      ~/rails_react_recipe/app/javascript/components/NewRecipe.jsx

      import React from "react";
      import { Link } from "react-router-dom";
      
      class NewRecipe extends React.Component {
        constructor(props) {
          super(props);
          this.state = {
            name: "",
            ingredients: "",
            instruction: ""
          };
      
          this.onChange = this.onChange.bind(this);
          this.onSubmit = this.onSubmit.bind(this);
          this.stripHtmlEntities = this.stripHtmlEntities.bind(this);
        }
      }
      
      export default NewRecipe;
      

      In the NewRecipe component’s constructor, you initialized your state object with empty name, ingredients, and instruction fields. These are the fields you need to create a valid recipe. You also have three methods; onChange, onSubmit, and stripHtmlEntities, which you bound to this. These methods will handle updating the state, form submissions, and converting special characters (like <) into their escaped/encoded values (like &lt;), respectively.

      Next, create the stripHtmlEntities method itself by adding the highlighted lines to the NewRecipe component:

      ~/rails_react_recipe/app/javascript/components/NewRecipe.jsx

      class NewRecipe extends React.Component {
        constructor(props) {
          super(props);
          this.state = {
            name: "",
            ingredients: "",
            instruction: ""
          };
      
          this.onChange = this.onChange.bind(this);
          this.onSubmit = this.onSubmit.bind(this);
          this.stripHtmlEntities = this.stripHtmlEntities.bind(this);
        }
      
        stripHtmlEntities(str) {
          return String(str)
            .replace(/</g, "&lt;")
            .replace(/>/g, "&gt;");
        }
      
      }
      
      export default NewRecipe;
      

      In the stripHtmlEntities method, you’re replacing the < and > characters with their escaped value. This way you’re not storing raw HTML in your database.

      Next add the onChange and onSubmit methods to the NewRecipe component to handle editing and submission of the form:

      ~/rails_react_recipe/app/javascript/components/NewRecipe.jsx

      class NewRecipe extends React.Component {
        constructor(props) {
          super(props);
          this.state = {
            name: "",
            ingredients: "",
            instruction: ""
          };
      
          this.onChange = this.onChange.bind(this);
          this.onSubmit = this.onSubmit.bind(this);
          this.stripHtmlEntities = this.stripHtmlEntities.bind(this);
        }
      
        stripHtmlEntities(str) {
          return String(str)
            .replace(/</g, "&lt;")
            .replace(/>/g, "&gt;");
        }
      
        onChange(event) {
          this.setState({ [event.target.name]: event.target.value });
        }
      
        onSubmit(event) {
          event.preventDefault();
          const url = "/api/v1/recipes/create";
          const { name, ingredients, instruction } = this.state;
      
          if (name.length == 0 || ingredients.length == 0 || instruction.length == 0)
            return;
      
          const body = {
            name,
            ingredients,
            instruction: instruction.replace(/n/g, "<br> <br>")
          };
      
          const token = document.querySelector('meta[name="csrf-token"]').content;
          fetch(url, {
            method: "POST",
            headers: {
              "X-CSRF-Token": token,
              "Content-Type": "application/json"
            },
            body: JSON.stringify(body)
          })
            .then(response => {
              if (response.ok) {
                return response.json();
              }
              throw new Error("Network response was not ok.");
            })
            .then(response => this.props.history.push(`/recipe/${response.id}`))
            .catch(error => console.log(error.message));
        }
      
      }
      
      export default NewRecipe;
      

      In the onChange method, you used the ES6 computed property names to set the value of every user input to its corresponding key in your state. In the onSubmit method, you checked that none of the required inputs are empty. You then build an object that contains the parameters required by the recipe controller to create a new recipe. Using regular expression, you replace every new line character in the instruction with a break tag, so you can retain the text format entered by the user.

      To protect against Cross-Site Request Forgery (CSRF) attacks, Rails attaches a CSRF security token to the HTML document. This token is required whenever a non-GET request is made. With the token constant in the preceding code, your application verifies the token on the server and throws an exception if the security token doesn't match what is expected. In the onSubmit method, the application retrieves the CSRF token embedded in your HTML document by Rails and makes a HTTP request with a JSON string. If the recipe is successfully created, the application redirects the user to the recipe page where they can view their newly created recipe.

      Lastly, add a render method that renders a form for the user to enter the details for the recipe the user wishes to create:

      ~/rails_react_recipe/app/javascript/components/NewRecipe.jsx

      class NewRecipe extends React.Component {
        constructor(props) {
          super(props);
          this.state = {
            name: "",
            ingredients: "",
            instruction: ""
          };
      
          this.onChange = this.onChange.bind(this);
          this.onSubmit = this.onSubmit.bind(this);
          this.stripHtmlEntities = this.stripHtmlEntities.bind(this);
        }
      
        stripHtmlEntities(str) {
          return String(str)
            .replace(/</g, "&lt;")
            .replace(/>/g, "&gt;");
        }
      
        onChange(event) {
          this.setState({ [event.target.name]: event.target.value });
        }
      
        onSubmit(event) {
          event.preventDefault();
          const url = "/api/v1/recipes/create";
          const { name, ingredients, instruction } = this.state;
      
          if (name.length == 0 || ingredients.length == 0 || instruction.length == 0)
            return;
      
          const body = {
            name,
            ingredients,
            instruction: instruction.replace(/n/g, "<br> <br>")
          };
      
          const token = document.querySelector('meta[name="csrf-token"]').content;
          fetch(url, {
            method: "POST",
            headers: {
              "X-CSRF-Token": token,
              "Content-Type": "application/json"
            },
            body: JSON.stringify(body)
          })
            .then(response => {
              if (response.ok) {
                return response.json();
              }
              throw new Error("Network response was not ok.");
            })
            .then(response => this.props.history.push(`/recipe/${response.id}`))
            .catch(error => console.log(error.message));
        }
      
        render() {
          return (
            <div className="container mt-5">
              <div className="row">
                <div className="col-sm-12 col-lg-6 offset-lg-3">
                  <h1 className="font-weight-normal mb-5">
                    Add a new recipe to our awesome recipe collection.
                  </h1>
                  <form onSubmit={this.onSubmit}>
                    <div className="form-group">
                      <label htmlFor="recipeName">Recipe name</label>
                      <input
                        type="text"
                        name="name"
                        id="recipeName"
                        className="form-control"
                        required
                        onChange={this.onChange}
                      />
                    </div>
                    <div className="form-group">
                      <label htmlFor="recipeIngredients">Ingredients</label>
                      <input
                        type="text"
                        name="ingredients"
                        id="recipeIngredients"
                        className="form-control"
                        required
                        onChange={this.onChange}
                      />
                      <small id="ingredientsHelp" className="form-text text-muted">
                        Separate each ingredient with a comma.
                      </small>
                    </div>
                    <label htmlFor="instruction">Preparation Instructions</label>
                    <textarea
                      className="form-control"
                      id="instruction"
                      name="instruction"
                      rows="5"
                      required
                      onChange={this.onChange}
                    />
                    <button type="submit" className="btn custom-button mt-3">
                      Create Recipe
                    </button>
                    <Link to="/recipes" className="btn btn-link mt-3">
                      Back to recipes
                    </Link>
                  </form>
                </div>
              </div>
            </div>
          );
        }
      
      }
      
      export default NewRecipe;
      

      In the render method, you have a form that contains three input fields; one for the recipeName, recipeIngredients, and instruction. Each input field has an onChange event handler that calls the onChange method. Also, there's an onSubmit event handler on the submit button that calls the onSubmit method which then submits the form data.

      Save and exit the file.

      To access this component in the browser, update your route file with its route:

      • nano app/javascript/routes/Index.jsx

      Update your route file to include these highlighted lines:

      ~/rails_react_recipe/app/javascript/routes/Index.jsx

      import React from "react";
      import { BrowserRouter as Router, Route, Switch } from "react-router-dom";
      import Home from "../components/Home";
      import Recipes from "../components/Recipes";
      import Recipe from "../components/Recipe";
      import NewRecipe from "../components/NewRecipe";
      
      export default (
        <Router>
          <Switch>
            <Route path="/" exact component={Home} />
            <Route path="/recipes" exact component={Recipes} />
            <Route path="/recipe/:id" exact component={Recipe} />
            <Route path="/recipe" exact component={NewRecipe} />
          </Switch>
        </Router>
      );
      

      With the route in place, save and exit your file. Restart your development server and visit http://localhost:3000 in your browser. Navigate to the recipes page and click the Create New Recipe button. You will find a page with a form to add recipes to your database:

      Create Recipe Page

      Enter the required recipe details and click the Create Recipe button; you will see the newly created recipe on the page.

      In this step, you brought your food recipe application to life by adding the ability to create recipes. In the next step, you’ll add the functionality to delete recipes.

      Step 9 — Deleting Recipes

      In this section, you will modify your Recipe component to be able to delete recipes.

      When you click the delete button on the recipe page, the application will send a request to delete a recipe from the database. To do this, open up your Recipe.jsx file:

      • nano app/javascript/components/Recipe.jsx

      In the constructor of the Recipe component, bind this to the deleteRecipe method:

      ~/rails_react_recipe/app/javascript/components/Recipe.jsx

      class Recipe extends React.Component {
        constructor(props) {
          super(props);
          this.state = { recipe: { ingredients: "" } };
          this.addHtmlEntities = this.addHtmlEntities.bind(this);
          this.deleteRecipe = this.deleteRecipe.bind(this);
        }
      ...
      

      Now add a deleteRecipe method to the Recipe component:

      ~/rails_react_recipe/app/javascript/components/Recipe.jsx

      class Recipe extends React.Component {
        constructor(props) {
          super(props);
          this.state = { recipe: { ingredients: "" } };
      
          this.addHtmlEntities = this.addHtmlEntities.bind(this);
          this.deleteRecipe = this.deleteRecipe.bind(this);
        }
      
        componentDidMount() {
          const {
            match: {
              params: { id }
            }
          } = this.props;
          const url = `/api/v1/show/${id}`;
          fetch(url)
            .then(response => {
              if (response.ok) {
                return response.json();
              }
              throw new Error("Network response was not ok.");
            })
            .then(response => this.setState({ recipe: response }))
            .catch(() => this.props.history.push("/recipes"));
        }
      
        addHtmlEntities(str) {
          return String(str)
            .replace(/&lt;/g, "<")
            .replace(/&gt;/g, ">");
        }
      
        deleteRecipe() {
          const {
            match: {
              params: { id }
            }
          } = this.props;
          const url = `/api/v1/destroy/${id}`;
          const token = document.querySelector('meta[name="csrf-token"]').content;
      
          fetch(url, {
            method: "DELETE",
            headers: {
              "X-CSRF-Token": token,
              "Content-Type": "application/json"
            }
          })
            .then(response => {
              if (response.ok) {
                return response.json();
              }
              throw new Error("Network response was not ok.");
            })
            .then(() => this.props.history.push("/recipes"))
            .catch(error => console.log(error.message));
        }
      
        render() {
          const { recipe } = this.state;
          let ingredientList = "No ingredients available";
      ... 
      

      In the deleteRecipe method, you get the id of the recipe to be deleted, then build your url and grab the CSRF token. Next, you make a DELETE request to the Recipes controller to delete the recipe. If the recipe is successfully deleted, the application redirects the user to the recipes page.

      To run the code in the deleteRecipe method whenever the delete button is clicked, pass it as the click event handler to the button. Add an onClick event to the delete button in the render method:

      ~/rails_react_recipe/app/javascript/components/Recipe.jsx

      ...
      return (
        <div className="">
          <div className="hero position-relative d-flex align-items-center justify-content-center">
            <img
              src={recipe.image}
              alt={`${recipe.name} image`}
              className="img-fluid position-absolute"
            />
            <div className="overlay bg-dark position-absolute" />
            <h1 className="display-4 position-relative text-white">
              {recipe.name}
            </h1>
          </div>
          <div className="container py-5">
            <div className="row">
              <div className="col-sm-12 col-lg-3">
                <ul className="list-group">
                  <h5 className="mb-2">Ingredients</h5>
                  {ingredientList}
                </ul>
              </div>
              <div className="col-sm-12 col-lg-7">
                <h5 className="mb-2">Preparation Instructions</h5>
                <div
                  dangerouslySetInnerHTML={{
                    __html: `${recipeInstruction}`
                  }}
                />
              </div>
              <div className="col-sm-12 col-lg-2">
                <button type="button" className="btn btn-danger" onClick={this.deleteRecipe}>
                  Delete Recipe
                </button>
              </div>
            </div>
            <Link to="/recipes" className="btn btn-link">
              Back to recipes
            </Link>
          </div>
        </div>
      );
      ...
      

      At this point in the tutorial, your complete Recipe.jsx file will look like this:

      ~/rails_react_recipe/app/javascript/components/Recipe.jsx

      import React from "react";
      import { Link } from "react-router-dom";
      
      class Recipe extends React.Component {
        constructor(props) {
          super(props);
          this.state = { recipe: { ingredients: "" } };
      
          this.addHtmlEntities = this.addHtmlEntities.bind(this);
          this.deleteRecipe = this.deleteRecipe.bind(this);
        }
      
        addHtmlEntities(str) {
          return String(str)
            .replace(/&lt;/g, "<")
            .replace(/&gt;/g, ">");
        }
      
        componentDidMount() {
          const {
            match: {
              params: { id }
            }
          } = this.props;
          const url = `/api/v1/show/${id}`;
          fetch(url)
            .then(response => {
              if (response.ok) {
                return response.json();
              }
              throw new Error("Network response was not ok.");
            })
            .then(response => this.setState({ recipe: response }))
            .catch(() => this.props.history.push("/recipes"));
        }
      
        deleteRecipe() {
          const {
            match: {
              params: { id }
            }
          } = this.props;
          const url = `/api/v1/destroy/${id}`;
          const token = document.querySelector('meta[name="csrf-token"]').content;
          fetch(url, {
            method: "DELETE",
            headers: {
              "X-CSRF-Token": token,
              "Content-Type": "application/json"
            }
          })
            .then(response => {
              if (response.ok) {
                return response.json();
              }
              throw new Error("Network response was not ok.");
            })
            .then(() => this.props.history.push("/recipes"))
            .catch(error => console.log(error.message));
        }
      
        render() {
          const { recipe } = this.state;
          let ingredientList = "No ingredients available";
          if (recipe.ingredients.length > 0) {
            ingredientList = recipe.ingredients
              .split(",")
              .map((ingredient, index) => (
                <li key={index} className="list-group-item">
                  {ingredient}
                </li>
              ));
          }
      
          const recipeInstruction = this.addHtmlEntities(recipe.instruction);
      
          return (
            <div className="">
              <div className="hero position-relative d-flex align-items-center justify-content-center">
                <img
                  src={recipe.image}
                  alt={`${recipe.name} image`}
                  className="img-fluid position-absolute"
                />
                <div className="overlay bg-dark position-absolute" />
                <h1 className="display-4 position-relative text-white">
                  {recipe.name}
                </h1>
              </div>
              <div className="container py-5">
                <div className="row">
                  <div className="col-sm-12 col-lg-3">
                    <ul className="list-group">
                      <h5 className="mb-2">Ingredients</h5>
                      {ingredientList}
                    </ul>
                  </div>
                  <div className="col-sm-12 col-lg-7">
                    <h5 className="mb-2">Preparation Instructions</h5>
                    <div
                      dangerouslySetInnerHTML={{
                        __html: `${recipeInstruction}`
                      }}
                    />
                  </div>
                  <div className="col-sm-12 col-lg-2">
                    <button type="button" className="btn btn-danger" onClick={this.deleteRecipe}>
                      Delete Recipe
                    </button>
                  </div>
                </div>
                <Link to="/recipes" className="btn btn-link">
                  Back to recipes
                </Link>
              </div>
            </div>
          );
        }
      }
      
      export default Recipe;
      

      Save and exit the file.

      Restart the application server and navigate to the homepage. Click the View Recipes button to view all existing recipes, view any individual recipe, and click the Delete Recipe button on the page to delete the article. You will be redirected to the recipes page, and the deleted recipe will no longer exists.

      With the delete button working, you now have a fully functional recipe application!

      Conclusion

      In this tutorial, you created a food recipe application with Ruby on Rails and a React frontend, using PostgreSQL as your database and Bootstrap for styling. If you'd like to run through more Ruby on Rails content, take a look at our Securing Communications in a Three-tier Rails Application Using SSH Tunnels tutorial, or head to our How To Code in Ruby series to refresh your Ruby skills. To dive deeper into React, try out our How To Display Data from the DigitalOcean API with React article.



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      How To Install Python 3 and Set Up a Programming Environment on Debian 10


      Introduction

      Python is a flexible and versatile programming language suitable for many use cases, including scripting, automation, data analysis, machine learning, and back-end development. First published in 1991 with a name inspired by the British comedy group Monty Python, the development team wanted to make Python a language that was fun to use. Quick to set up with immediate feedback on errors, Python is a useful language to learn for beginners and experienced developers alike. Python 3 is the most current version of the language and is considered to be the future of Python.

      This tutorial will get your Debian 10 server set up with a Python 3 programming environment. Programming on a server has many advantages and supports collaboration across development projects.

      Prerequisites

      In order to complete this tutorial, you should have a non-root user with sudo privileges on a Debian 10 server. To learn how to achieve this setup, follow our Debian 10 initial server setup guide.

      If you’re not already familiar with a terminal environment, you may find the article “An Introduction to the Linux Terminal” useful for becoming better oriented with the terminal.

      With your server and user set up, you are ready to begin.

      Step 1 — Setting Up Python 3

      Debian Linux ships with both Python 3 and Python 2 pre-installed. To make sure that our versions are up-to-date, let’s update and upgrade the system with the apt command to work with the Advanced Packaging Tool:

      • sudo apt update
      • sudo apt -y upgrade

      The -y flag will confirm that we are agreeing for all items to be installed.

      Once the process is complete, we can check the version of Python 3 that is installed in the system by typing:

      You’ll receive output in the terminal window that will let you know the version number. While this number may vary, the output will be similar to this:

      Output

      Python 3.7.3

      To manage software packages for Python, let’s install pip, a tool that will install and manage programming packages we may want to use in our development projects. You can learn more about modules or packages that you can install with pip by reading “How To Import Modules in Python 3.”

      • sudo apt install -y python3-pip

      Python packages can be installed by typing:

      • pip3 install package_name

      Here, package_name can refer to any Python package or library, such as Django for web development or NumPy for scientific computing. So if you would like to install NumPy, you can do so with the command pip3 install numpy.

      There are a few more packages and development tools to install to ensure that we have a robust set-up for our programming environment:

      • sudo apt install build-essential libssl-dev libffi-dev python3-dev

      Once Python is set up, and pip and other tools are installed, we can set up a virtual environment for our development projects.

      Step 2 — Setting Up a Virtual Environment

      Virtual environments enable you to have an isolated space on your server for Python projects, ensuring that each of your projects can have its own set of dependencies that won’t disrupt any of your other projects.

      Setting up a programming environment provides us with greater control over our Python projects and over how different versions of packages are handled. This is especially important when working with third-party packages.

      You can set up as many Python programming environments as you want. Each environment is basically a directory or folder on your server that has a few scripts in it to make it act as an environment.

      While there are a few ways to achieve a programming environment in Python, we’ll be using the venv module here, which is part of the standard Python 3 library. Let’s install venv by typing:

      • sudo apt install -y python3-venv

      With this installed, we are ready to create environments. Let’s either choose which directory we would like to put our Python programming environments in, or create a new directory with mkdir, as in:

      • mkdir environments
      • cd environments

      Once you are in the directory where you would like the environments to live, you can create an environment by running the following command:

      Essentially, pyvenv sets up a new directory that contains a few items which we can view with the ls command:

      Output

      bin include lib lib64 pyvenv.cfg share

      Together, these files work to make sure that your projects are isolated from the broader context of your local machine, so that system files and project files don’t mix. This is good practice for version control and to ensure that each of your projects has access to the particular packages that it needs. Python Wheels, a built-package format for Python that can speed up your software production by reducing the number of times you need to compile, will be in the Ubuntu 18.04 share directory.

      To use this environment, you need to activate it, which you can achieve by typing the following command that calls the activate script:

      • source my_env/bin/activate

      Your command prompt will now be prefixed with the name of your environment, in this case it is called my_env. Depending on what version of Debian Linux you are running, your prefix may appear somewhat differently, but the name of your environment in parentheses should be the first thing you see on your line:

      This prefix lets us know that the environment my_env is currently active, meaning that when we create programs here they will use only this particular environment’s settings and packages.

      Note: Within the virtual environment, you can use the command python instead of python3, and pip instead of pip3 if you would prefer. If you use Python 3 on your machine outside of an environment, you will need to use the python3 and pip3 commands exclusively.

      After following these steps, your virtual environment is ready to use.

      Step 3 — Creating a “Hello, World” Program

      Now that we have our virtual environment set up, let’s create a traditional “Hello, World!” program. This will let us test our environment and provides us with the opportunity to become more familiar with Python if we aren’t already.

      To do this, we’ll open up a command-line text editor such as nano and create a new file:

      Once the text file opens up in the terminal window we’ll type out our program:

      print("Hello, World!")
      

      Exit nano by typing the CTRL and X keys, and when prompted to save the file press y.

      Once you exit out of nano and return to your shell, let’s run the program:

      The hello.py program that you just created should cause your terminal to produce the following output:

      Output

      Hello, World!

      To leave the environment, simply type the command deactivate and you will return to your original directory.

      Conclusion

      Congratulations! At this point you have a Python 3 programming environment set up on your Debian 10 Linux server and you can now begin a coding project!

      If you are using a local machine rather than a server, refer to the tutorial that is relevant to your operating system in our “How To Install and Set Up a Local Programming Environment for Python 3” series.

      With your server ready for software development, you can continue to learn more about coding in Python by reading our free How To Code in Python 3 eBook, or consulting our Programming Project tutorials.

      Download our free Python eBook!

      How To Code in Python eBook in EPUB format

      How To Code in Python eBook in PDF format



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      How To Set Up Time Synchronization on Debian 10


      Introduction

      Accurate timekeeping has become a critical component of modern software deployments. Whether it’s making sure logs are recorded in the right order or database updates are applied correctly, out-of-sync time can cause errors, data corruption, and other difficult issues to debug.

      Debian 10 has time synchronization built in and activated by default using the standard ntpd time server, provided by the ntp package. In this article we will look at some basic time-related commands, verify that ntpd is active and connected to peers, and learn how to activate the alternate systemd-timesyncd network time service.

      Prerequisites

      Before starting this tutorial, you will need a Debian 10 server with a non-root, sudo-enabled user, as described in this Debian 10 server setup tutorial.

      Step 1 — Navigating Basic Time Commands

      The most basic command for finding out the time on your server is date. Any user can type this command to print out the date and time:

      Output

      Wed 31 Jul 2019 06:03:19 PM UTC

      Most often your server will default to the UTC time zone, as highlighted in the above output. UTC is Coordinated Universal Time, the time at zero degrees longitude. Consistently using Universal Time reduces confusion when your infrastructure spans multiple time zones.

      If you have different requirements and need to change the time zone, you can use the timedatectl command to do so.

      First, list the available time zones:

      • timedatectl list-timezones

      A list of time zones will print to your screen. You can press SPACE to page down, and b to page up. Once you find the correct time zone, make note of it then type q to exit the list.

      Now set the time zone with timedatectl set-timezone, making sure to replace the highlighted portion below with the time zone you found in the list. You'll need to use sudo with timedatectl to make this change:

      • sudo timedatectl set-timezone America/New_York

      You can verify your changes by running date again:

      Output

      Wed 31 Jul 2019 02:08:43 PM EDT

      The time zone abbreviation should reflect the newly chosen value.

      Now that we know how to check the clock and set time zones, let’s make sure our time is being synchronized properly.

      Step 2 — Checking the Status of ntpd

      By default, Debian 10 runs the standard ntpd server to keep your system time synchronized with a pool of external time servers. We can check that it's running with the systemctl command:

      • sudo systemctl status ntp

      Output

      ● ntp.service - Network Time Service Loaded: loaded (/lib/systemd/system/ntp.service; enabled; vendor preset: enabled) Active: active (running) since Wed 2019-07-31 13:57:08 EDT; 17min ago Docs: man:ntpd(8) Main PID: 429 (ntpd) Tasks: 2 (limit: 1168) Memory: 2.1M CGroup: /system.slice/ntp.service └─429 /usr/sbin/ntpd -p /var/run/ntpd.pid -g -u 106:112 . . .

      The active (running) status indicates that ntpd started up properly. To get more information about the status of ntpd we can use the ntpq command:

      Output

      remote refid st t when poll reach delay offset jitter ============================================================================== 0.debian.pool.n .POOL. 16 p - 64 0 0.000 0.000 0.000 1.debian.pool.n .POOL. 16 p - 64 0 0.000 0.000 0.000 2.debian.pool.n .POOL. 16 p - 64 0 0.000 0.000 0.000 3.debian.pool.n .POOL. 16 p - 64 0 0.000 0.000 0.000 +208.67.72.50 152.2.133.55 2 u 12 64 377 39.381 1.696 0.674 +198.46.223.227 204.9.54.119 2 u 6 64 377 22.671 3.536 1.818 -zinc.frizzen.ne 108.61.56.35 3 u 43 64 377 12.012 1.268 2.553 -pyramid.latt.ne 204.123.2.72 2 u 11 64 377 69.922 2.858 0.604 +nu.binary.net 128.252.19.1 2 u 10 64 377 35.362 3.148 0.587 #107.155.79.108 129.7.1.66 2 u 65 64 377 42.380 1.638 1.014 +t1.time.bf1.yah 98.139.133.62 2 u 6 64 377 11.233 3.305 1.118 *sombrero.spider 129.6.15.30 2 u 47 64 377 1.304 2.941 0.889 +hydrogen.consta 209.51.161.238 2 u 45 64 377 1.830 2.280 1.026 -4.53.160.75 142.66.101.13 2 u 42 64 377 29.077 2.997 0.789 #horp-bsd01.horp 146.186.222.14 2 u 39 64 377 16.165 4.189 0.717 -ntpool1.603.new 204.9.54.119 2 u 46 64 377 27.914 3.717 0.939

      ntpq is a query tool for ntpd. The -p flag asks for information about the NTP servers (or peers) ntpd is connected to. Your output will be slightly different, but should list the default Debian pool servers plus a few others. Bear in mind that it can take a few minutes for ntpd to establish connections.

      Step 3 — Switching to systemd-timesyncd

      It is possible to use systemd's built-in timesyncd component to replace ntpd. timesyncd is a lighter-weight alternative to ntpd that is more integrated with systemd. Note, however, that it doesn't support running as a time server, and it is slightly less sophisticated in the techniques it uses to keep your system time in sync. If you are running complex real-time distributed systems, you may want to stick with ntpd.

      To use timesyncd, we must first uninstall ntpd:

      Then, start up the timesyncd service:

      • sudo systemctl start systemd-timesyncd

      Finally, check the status of the service to make sure it's running:

      • sudo systemctl status systemd-timesyncd

      Output

      ● systemd-timesyncd.service - Network Time Synchronization Loaded: loaded (/lib/systemd/system/systemd-timesyncd.service; enabled; vendor preset: enabled) Drop-In: /usr/lib/systemd/system/systemd-timesyncd.service.d └─disable-with-time-daemon.conf Active: active (running) since Wed 2019-07-31 14:21:37 EDT; 6s ago Docs: man:systemd-timesyncd.service(8) Main PID: 1681 (systemd-timesyn) Status: "Synchronized to time server for the first time 96.245.170.99:123 (0.debian.pool.ntp.org)." Tasks: 2 (limit: 1168) Memory: 1.3M CGroup: /system.slice/systemd-timesyncd.service └─1681 /lib/systemd/systemd-timesyncd

      We can use timedatectl to print out systemd's current understanding of the time:

      Output

      Local time: Wed 2019-07-31 14:22:15 EDT Universal time: Wed 2019-07-31 18:22:15 UTC RTC time: n/a Time zone: America/New_York (EDT, -0400) System clock synchronized: yes NTP service: active RTC in local TZ: no

      This prints out the local time, universal time (which may be the same as local time, if you didn't switch from the UTC time zone), and some network time status information. System clock synchronized: yes means that the time has been successfully synced, and NTP service: active means that timesyncd is enabled and running.

      Conclusion

      In this article we’ve shown how to view the system time, change time zones, work with ntpd, and switch to systemd's timesyncd service. If you have more sophisticated timekeeping needs than what we’ve covered here, you might refer to the offical NTP documentation, and also take a look at the NTP Pool Project, a global group of volunteers providing much of the world's NTP infrastructure.



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