Installation First App Routing Error Handling

Getting Started

Learn how to set up and build your first Eiseniiiia application with clear, step-by-step instructions.

1. Installation


// Via npm
npm install eiseniiiia

// Via CDN
<script src="https://cdn.eiseniiiia.dev/1.0.0/index.js"></script>

                    

Use npm for local development or add the CDN link to your HTML file for quick prototyping.

2. Your First App


import { Router } from 'eiseniiiia';

const app = Router();

app.get('/', (req, res) => {
  res.send('Hello, Eiseniiiia!');
});

app.listen(3000, () => {
  console.log('Server running at http://localhost:3000');
});

                        
Basic server setup with a single route

How It Works

This example creates a Router instance, defines a basic '/' route, and starts the server on port 3000. The res.send() method sends a simple HTML response.

GET /
PORT 3000

3. Advanced Routing

Build complex routing with parameterized paths and middleware.


app.get('/user/:id', (req, res) => {
  res.json({
    id: req.params.id,
    message: 'User details'
  });
});

                        
Route with parameterized path
Request Flow
URL: /user/123
Route Handler

4. Error Handling

Implement global error handling with custom middleware.


app.use((err, req, res, next) => {
  res.status(500).json({
    error: "Server Error",
    details: err.message
  });
});

                        
Global error middleware

Demo Response

HTTP/1.1 500 Internal Server Error 192 B
{"error":"Server Error","details":"Internal error message"}