Setting Up a Backend Project with Node.js

To start a backend project.

- npm init

Then make a file with whatever entry point you named it as, for example, server.js

Once package.json is created:

• npm i <package>
• connect-mongo (store sessions in DB)
• dotenv (for config files, environment variables)
• express
• mongoose
• express-sessions (sessions and cookies)
• method-override (to use PUT, UPDATE, DELETE requests)
• moments (date formatting)
• morgan (logging)
• passport (authentication)

npm i -D <package>

• nodemon (Update every file change instantly without having to restart the server)
• cross-env (To update environment variables in script definition itself)

After installing the dependencies, edit the scripts in package.json

The initial setup is now done.

Now in server.js, get express and dotenv.

To load the config file:

dotenv.config({path: <path to .env file>});

Then to load express:

const app = express();

Create a database collection in MongoDB compass or in MongoDB atlas, then store the connection string.

If you created the database in compass, then the connection string will be:

mongodb://localhost:27017/<project name>

If you take the connection string from atlas, then it will be of the form:

mongodb+srv://<username>:<password>@<user>cluster.cbmll.mongodb.net/<dbname>?retryWrites=true&w=majority

Once you copy this, store this string into an environment variable in your .env file.

You can access env variables using "process.env".

To start the server:

app. listen(<port number>, <some function>);

To run:

npm run <script name>

Ex: npm run dev or npm run start from the above script example

To connect to the database:

First get mongoose:

const mongoose = require("mongoose");

Then:

This connects to the database, and as it returns a promise, we run it as an async function. If it doesn't connect, it terminates the program.

To define what happens in a particular route:

In index.js file in a routes folder:

const router = express.Router();

router.get('/<path>', (req, res) => {

  //functionality

})

module.exports = router;

Back in server.js:

const routes = require("./routes/index");

app.use("/<path>", routes);