Prerequisite
- Express -
npm install express - Express Sessions -
npm install express-session - MySQL Server
- MySQL for Node.js -
npm install MySQL - Node.js
Lets Get Started
First, create a folder called auth cd into the folder and run the following command on your terminal
npm init
On the prompt type login and on the prompt for entry point type login.js.
Afterward, the prerequisite packages will be installed
npm install express
npm install express-session
npm install MySQL
Create Login Function
In your login.js, you need to include the following packages
var mysql = require('mysql');
var express = require('express');
var session = require('express-session');
var bodyParser = require('body-parser');
var path = require('path');
DB Connection
You can run the following in your console or using your preferred MySQL
CREATE DATABASE IF NOT EXISTS `auth` DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci;
USE auth;
CREATE TABLE IF NOT EXISTS `users` (
`id` int(11) NOT NULL,
`username` varchar(50) NOT NULL,
`password` varchar(255) NOT NULL,
`email` varchar(100) NOT NULL
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;
INSERT INTO users (`id`, `username`, `password`, `email`) VALUES (1, 'jeremiahiro', 'password1', 'jeremiahiro@gmail.com');
ALTER TABLE 'accounts' ADD PRIMARY KEY ('id');
ALTER TABLE 'accounts' MODIFY 'id' int(11) NOT NULL AUTO_INCREMENT,AUTO_INCREMENT=2;
This will create a database with the name auth and the table users and also insert test credentials.
Next up we will try to connect to the database using the following commands.
var connection = mysql.createConnection({
host : 'localhost',
user : 'root',
password : '',
database : 'auth'
});
We would use Express which was installed earlier, this is because it includes packages that will help in sessions and handling HTTP requests
var app = express();
app.use(session({
secret: 'secret',
resave: true,
saveUninitialized: true
}));
app.use(bodyParser.urlencoded({extended : true}));
app.use(bodyParser.json());
N/B: change the secret code for the sessions as the sessions will be used to determine if a user is logged in or not.
The bodyParser is used to extract data from the login form.
To display our login form we use the following
app.get('/', function(request, response) {
response.sendFile(path.join(__dirname + '/login.html'));
});
I'm assuming you have a beautifully styled form named login.html
To handle the POST request form the login form action should be /login.
// for action
app.post('/login', function(request, response) {
var username = request.body.username;
var password = request.body.password;
if (username && password) {
// check if user exists
connection.query('SELECT * FROM users WHERE username = ? AND password = ?', [username, password], function(error, results, fields) {
if (results.length > 0) {
request.session.loggedin = true;
request.session.username = username;
response.redirect('/home');
} else {
response.send('Incorrect Username and/or Password!');
}
response.end();
});
} else {
response.send('Please enter Username and Password!');
response.end();
}
});
One the user is authenticated, we can not redirect to our application home page or dashboard
app.get('/dashboard', function(request, response) {
if (request.session.loggedin) {
response.send('Welcome back, ' + request.session.username + '!');
} else {
response.send('Please login to view this page!');
}
response.end();
});
For testing our application, it needs to listen to a port at such we will use port 3000
app.listen(3000);
That's all we need to create a basic login.
Discussion
Loved this short and simple article man. It was a great help to my DBMS project.
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