Lecture 286:- Create a Controller

To create a controller in an Express app, you can create a new file in the controllers directory with a name that corresponds to the route you want to handle. For example, if you want to create a controller to handle requests to the /users route, you can create a file called users.js in the controllers directory.

In this file, you can export an object that defines the functions to handle different HTTP requests. For example:

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const usersController = {  getUsers(req, res) {    // code to get users from database    res.send('List of users');  },  getUserById(req, res) {    const { id } = req.params;    // code to get user with given id from database    res.send(`User with id ${id}`);  },  createUser(req, res) {    const { body } = req;    // code to create user in database    res.send(`User created with name ${body.name}`);  },  updateUser(req, res) {    const { id } = req.params;    const { body } = req;    // code to update user with given id in database    res.send(`User with id ${id} updated with name ${body.name}`);  },  deleteUser(req, res) {    const { id } = req.params;    // code to delete user with given id from database    res.send(`User with id ${id} deleted`);  } }; module.exports = usersController;

Then, in the routes.js file, you can import the usersController object and map its functions to the appropriate HTTP methods and routes using the express.Router object. For example:

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const express = require('express'); const router = express.Router(); const usersController = require('./controllers/users'); router.get('/users', usersController.getUsers); router.get('/users/:id', usersController.getUserById); router.post('/users', usersController.createUser); router.put('/users/:id', usersController.updateUser); router.delete('/users/:id', usersController.deleteUser); module.exports = router;

This sets up the routing for the /users route and its subroutes using the functions defined in the usersController object.