Introduction to connect-mongodb-session

connect-mongodb-session is a MongoDB-backed session store for Express and Connect-based Node.js applications. This module allows developers to store session data in a MongoDB database, facilitating the management of user sessions in a scalable and efficient manner.

In this guide, we will explore various APIs provided by connect-mongodb-session through practical code snippets and an app example.

Setting Up connect-mongodb-session

  
    const session = require('express-session');
    const MongoDBStore = require('connect-mongodb-session')(session);

    const store = new MongoDBStore({
      uri: 'mongodb://localhost:27017/connect_mongodb_session_test',
      collection: 'mySessions'
    });

    store.on('error', function(error) {
      console.log(error);
    });

    app.use(require('express-session')({
      secret: 'This is a secret',
      cookie: {
        maxAge: 1000 * 60 * 60 * 24 * 14 // 14 days
      },
      store: store,
      resave: true,
      saveUninitialized: true
    }));
  

Fetching a Session from the Database

  
    store.get('sessionId', function(error, session) {
      if (error) {
        console.log(error);
      } else {
        console.log(session);
      }
    });
  

Creating and Updating Sessions

  
    store.set('sessionId', { foo: 'bar' }, function(error) {
      if (error) {
        console.log(error);
      }
    });
  

Destroying a Session

  
    store.destroy('sessionId', function(error) {
      if (error) {
        console.log(error);
      }
    });
  

Counting Sessions

  
    store.length(function(error, count) {
      if (error) {
        console.log(error);
      } else {
        console.log(count);
      }
    });
  

Example App

Here’s a simple Express app demonstrating the usage of connect-mongodb-session:

  
    const express = require('express');
    const session = require('express-session');
    const MongoDBStore = require('connect-mongodb-session')(session);

    const app = express();

    const store = new MongoDBStore({
      uri: 'mongodb://localhost:27017/connect_mongodb_session_test',
      collection: 'mySessions'
    });

    store.on('error', function(error) {
      console.log(error);
    });

    app.use(session({
      secret: 'This is a secret',
      resave: true,
      saveUninitialized: true,
      store: store
    }));

    app.get('/', (req, res) => {
      if (req.session.views) {
        req.session.views++;
        res.setHeader('Content-Type', 'text/html');
        res.write(`
views: ${req.session.views}
`);
        res.write('
expires in: ' + (req.session.cookie.maxAge / 1000) + 's
');
        res.end();
      } else {
        req.session.views = 1;
        res.end('welcome to the session demo. refresh!');
      }
    });

    app.listen(3000, () => {
      console.log('App is listening on port 3000');
    });
  

If you have any questions or comments, feel free to leave them below!

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