{"id":110313,"date":"2021-06-14T07:00:00","date_gmt":"2021-06-14T04:00:00","guid":{"rendered":"https:\/\/www.javacodegeeks.com\/?p=110313"},"modified":"2021-06-07T14:17:14","modified_gmt":"2021-06-07T11:17:14","slug":"express-js-sessions-tutorial","status":"publish","type":"post","link":"https:\/\/www.javacodegeeks.com\/express-js-sessions-tutorial.html","title":{"rendered":"Express.js Sessions Tutorial"},"content":{"rendered":"

Hello! In this tutorial, we will explain the Express.js sessions. We will understand how to manage sessions in a Node.js application. HTTP<\/strong> is a stateless protocol<\/em> and to manage sessions in a Node.js application we will use the express-session<\/code> dependency.<\/p>\n

1. Introduction<\/h2>\n

To set up this application we will put the expression-session<\/code> and cookie-parser<\/code> middleware dependencies in place. But before doing any programming stuff we will need to install Node.js on windows and you can download the installer from this<\/a> link. Click on the installer (also include the NPM package manager) for your platform and run the installer to start with the Node.js setup wizard. Follow the wizard steps and click on Finish when it is done. If everything goes well you can navigate to the command prompt to verify if the installation was successful as shown in Fig. 1.<\/p>\n

\n
\"express<\/a>
Fig. 1: Verifying node and npm installation<\/figcaption><\/figure>\n<\/div>\n

2. Express.js Sessions Tutorial<\/h2>\n

To set up the Express.js server, we will need to navigate a path where our project will reside. For programming stuff, I am using Visual Studio Code<\/a> as my preferred IDE. You’re free to choose the IDE of your choice.<\/p>\n

2.1 Setting up dependencies<\/h3>\n

Navigate to a directory and run npm init -y<\/code> to create a package.json<\/code> file. This file<\/a> holds the metadata relevant to the project and is used for managing the project dependencies, script, version, etc. Add the following code to the file wherein we will specify the dependencies.

<\/div> <\/div><\/p>\n

package.json<\/em><\/span><\/p>\n

{\n  \"name\": \"expressjs-session\",\n  \"version\": \"1.0.0\",\n  \"description\": \"\",\n  \"main\": \"index.js\",\n  \"scripts\": {\n    \"test\": \"echo \\\"Error: no test specified\\\" && exit 1\",\n    \"start\": \"node index.js\"\n  },\n  \"keywords\": [],\n  \"author\": \"\",\n  \"license\": \"ISC\",\n  \"dependencies\": {\n    \"express\": \"^4.17.1\",\n    \"express-session\": \"^1.17.2\",\n    \"cookie-parser\": \"^1.4.5\"\n  },\n  \"devDependencies\": {\n    \"nodemon\": \"^2.0.7\"\n  }\n}\n<\/pre>\n
To download the dependencies navigate to the directory path containing the file and use the npm install<\/code> command. If everything goes well the dependencies will be loaded inside the node_modules<\/code> folder and you are good to go with the further steps.<\/p>\n
2.2 Creating an Express server<\/h3>\n
Add the following programming stuff to the index.js<\/code> file and we will import the expression-session<\/code> and cookie-parser<\/code> middleware modules. Whenever a user will make an introductory request a new session will be created for the user. Now when another request from the same user comes, the application will already have their session information stored.<\/p>\n
index.js<\/em><\/span><\/p>\n
const express = require('express');\nconst cookieParser = require('cookie-parser');\nconst session = require('express-session');\n\nconst app = express();\napp.use(cookieParser());\n\/\/ using secret for cookie handling\napp.use(session(\n    {\n        secret: 'Your_Secret_Key',   \/\/ used to sign the session id cookie\n        saveUninitialized: true,     \/\/ forces the session that is \"uninitialized\" to be saved to the store\n        resave: false                     \/\/ forces the session to be saved back to the session store, even if a session was not modified by request\n    }\n));\n\n\/\/ endpoint\n\/\/ http:\/\/localhost:4001\/session\napp.get('\/session', function (req, res) {\n    if (req.session.page_views) {\n        \/\/ incrementing the page views counter by 1\n        req.session.page_views++;\n        res.status(200).json({info: `Welcome to this tutorial. Visit counter : ${req.session.page_views}`});\n    } else {\n        \/\/ introductory request\n        \/\/ setting the page views counter to 1\n        req.session.page_views = 1;\n        res.status(200).json({info: 'Welcome to this tutorial for the first time'});\n    }\n});\n\nconst PORT = process.env.port || 4001;\napp.listen(PORT, () => {\n    console.log(`Server started on port ${PORT}`);\n});\n<\/pre>\n
3. Run the Application<\/h2>\n
To launch the application navigate to the project directory and enter the following command as shown in Fig. 2. If everything goes well the application will be started successfully on port number 4001<\/code>.<\/p>\n
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\"express<\/a>
Fig. 2: Launch the application<\/figcaption><\/figure>\n<\/div>\n
4. Project Demo<\/h2>\n
When the application is started, open the browser and enter the following url – http:\/\/localhost:4001\/session<\/code>. If the request will be the first the following message will be shown to the user – Welcome to this tutorial for the first time<\/em> and if the user sends the repeated requests the message with display a page visit counter. That is all for this tutorial and I hope the article served you with whatever you were looking for. Happy Learning and do not forget to share!<\/p>\n
5. Summary<\/h2>\n
In this tutorial, we learned:<\/p>\n