How to Send and Display Flash Messages in Nodejs

1. Set Up Your Node.js Application:

First, make sure you have a Node.js application set up with a web framework like Express.js. If you haven't already, you can create a basic Express.js application:

npm install express

2. Install Required Packages:

You'll need the following packages to implement flash messages:

npm install express-session connect-flash

3. Configure Express.js Middleware:

In your Node.js application, configure the necessary middleware for session management and flash messages.

const express = require('express');
const session = require('express-session');
const flash = require('connect-flash');
const app = express();

// Session middleware
app.use(session({
  secret: 'your-secret-key', // Replace with a secret key
  resave: false,
  saveUninitialized: false,
}));

// Flash messages middleware
app.use(flash());

4. Create Routes for Flash Messages:

Define routes in your application where you want to use flash messages. Typically, flash messages are used for form submissions, authentication, and other user interactions.

app.get('/login', (req, res) => {
  // Render the login form
  res.render('login');
});

app.post('/login', (req, res) => {
  // Check login credentials (replace with your authentication logic)
  if (validUser) {
    req.flash('success', 'Login successful!');
    res.redirect('/dashboard');
  } else {
    req.flash('error', 'Invalid username or password');
    res.redirect('/login');
  }
});

5. Render Flash Messages in Views:

In your view templates (e.g., using a template engine like EJS or Handlebars), display flash messages to the user. You can typically render flash messages in the layout or on specific pages where feedback is required.

<% if (messages.success) { %>
  

    <%= messages.success %>
  
<% } %>

<% if (messages.error) { %>
  

    <%= messages.error %>
  
<% } %>

6. Pass Flash Messages to Views:

When rendering a page, pass the flash messages to the view context so they can be displayed.

app.get('/dashboard', (req, res) => {
  // Pass flash messages to the view context
  res.render('dashboard', { messages: req.flash() });
});

7. Define CSS Styles:

Style your flash messages using CSS to make them visually appealing and easy to notice. You can use Bootstrap alerts or customize the styles according to your application's design.

By following these steps, you can implement flash messages in your Node.js application to provide feedback to users about various actions and events. Flash messages are a useful way to communicate success messages, errors, or other important information temporarily while maintaining a good user experience.