README.md

AdvancedNodeApp

Advanced code for Nodejs applications using Express.
Author: Francis Rodrigues

Setup environment

• Run npm install in the root of the project to install server dependencies
• Change into the client directory and run npm install --legacy-peer-deps
• Change back into the root of the project and run npm run dev to start the server
• Access the application at localhost:3000 in your browser

Important: The credentials for the Mongo Atlas DB in dev.js are read only. If you attempt to log in without first adding your own connection string (covered later in the course) you will see an error: [0] MongoError: user is not allowed to do action [insert] on [advnode.users]

Implementing cache with Redis

app.get('/api/blogs', requireLogin, async (req, res) => {
  const redis = require('redis');
  const util = require('util');

  const redisUrl = 'redis://127.0.0.1:6379';
  const client = redis.createClient(redisUrl);

  // Wraps client.get into a Promise.
  client.get = util.promisify(client.get);

  // Do we have any cached data in Redis related to this query.
  const cachedBlogs = await client.get(req.user.id);

  // if yes, then respond to the request right away and return it.
  if (cachedBlogs) {
    console.log('SERVING FROM CACHE..');
    return res.send(JSON.parse(cachedBlogs));
  }

  // if no, we need to respond to request and update our cache
  // to store the data
  const blogs = await Blog.find({ _user: req.user.id });

  console.log('SERVING FROM MONGODB..');
  res.send(blogs);

  client.set(req.user.id, JSON.stringify(blogs));
});

Sources to learn more

• Starting project for a course on Advanced Node - @Udemy

License

MIT