Rest API with Express.JS

Build your API with Express.JS

2022-02-20 386 words 2 minutes views

Contents

To include packages/files

Include packages: packages are from package.json

const express = require('express');
const router = express.Router();
		router.get('/', (req, res) => res.send('Profile route'));

const jwt = require('jsonwebtoken');

Inlucde route/file:

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// db.js module.exports = connectDB;
// In server.js
const connectDB = require('./config/db')
connectDB();

File return

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module.exports = connectDB;
module.exports = router;

Try catch

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const connectDB = async () => {
    try{
        await mongoose.connect(db, {
            useNewUrlParser: true
        });

        console.log('MongoDB Connected!');
    } catch(err){
        console.error(err.message);
        // Exit process with failure
        process.exit(1);
    }
}

Build Express API:

Hierarchy

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// server.js
const express = require('express');
const app = express()

app.get('/', (req, res) => res.send('API Running'));
// Define Routes
app.use('/api/users', require('./routes/api/users'));
app.use('/api/auth', require('./routes/api/auth'));
app.use('/api/profile', require('./routes/api/profile'));
app.use('/api/posts', require('./routes/api/posts'));

const PORT = process.env.PORT || 5000;
//app.listen() starts a port and host to listen to incoming requests from a client.
app.listen(PORT, () => console.log(`Server started on port ${PORT}`));

////////////////////////////////////////////////////////////////////////
// profile.js
const express = require('express');
const router = express.Router();

// Postman --Get request--> http://localhost:5000/api/profile
// res.send --> 'Profile route' --> Postman
router.get('/', (req, res) => res.send('Profile route'));

module.exports = router;

Notes regarding REST API

Requests are third party requests sent to our sever(such as Postman)
Router.post/get/put/delete: it is how we handle incoming requests ( requests sent to our server)
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router.post/get/put/delete('/', auth, async (req, res) => { do some response here});

Express.Router() use req,res to handle requests

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req: contains POST request JSON body
	const {name, email, password} = req.body
res: is whatever info the server sends back
	res.status(500).send('Server error');
	res.status(400).json({errors: [{msg: 'User already exists'}]});
	res.json({ msg: 'User deleted' });

More about REST API

POST:

Requester sends info and data to a server
POST request has a body (JSON) and a header (Content-Type, application/json , x-auth-token)

GET:

DON’T have a body When a request is sent to our sever’s route, our server responds a message back (router.get(’/’, (req, res) => res.send(‘Profile route’));)
Can have a header (x-auth-token)

PUT:

Work like a POST, have body & header. But it meanly used to update a resource

Delete:

Delete a resource in DB, usually require a x-auth-token in the header