expressjsHow can I use Express.js decorators to create a dynamic web application?

Express.js decorators allow developers to create a dynamic web application with ease. The decorators provide a way to dynamically change the behavior of an application without changing the code.

For example, the following code uses the express.decorate() decorator to add a /hello route to the application.

const express = require('express')
const app = express()

app.decorate('hello', (req, res) => {
  res.send('Hello World!')
})

app.listen(3000, () => {
  console.log('Server running on port 3000')
})

Output example

Server running on port 3000

The code above adds a /hello route to the application. When a request is made to the /hello route, the express.decorate() decorator will execute the function and send the response Hello World!.

The decorator can also be used to add dynamic behavior to the application. For example, the following code uses the express.decorate() decorator to add a /user route with dynamic behavior.

app.decorate('user', (req, res) => {
  let userId = req.params.userId
  res.send(`User ${userId}`)
})

When a request is made to the /user/:userId route, the express.decorate() decorator will execute the function and send the response User {userId} where {userId} is the value of the userId parameter.

By using Express.js decorators, developers can easily create a dynamic web application.

Helpful links

• Express.js Decorators
• Express.js Routing

Edit this code on GitHub