Express: Handling form data

This is an example of an HTML form:

<form method="POST" action="/submit-form">
  <input type="text" name="username" />
  <input type="submit" />

When the user presses the submit button, the browser will automatically make a POST request to the /submit-form URL on the same origin of the page. The browser sends the data contained, encoded as application/x-www-form-urlencoded. In this particular example, the form data contains the username input field value.

Forms can also send data using the GET method, but the vast majority of the forms you’ll build will use POST.

The form data will be sent in the POST request body.

To extract it, you will need to use the express.urlencoded() middleware:

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

  extended: true

Now, you need to create a POST endpoint on the /submit-form route, and any data will be available on Request.body:'/submit-form', (req, res) => {
  const username = req.body.username

Don’t forget to validate the data before using it.

Lessons in this unit:

0: Introduction
1: Introduction to Express
2: Request parameters
3: Send a response to the client
4: Send a JSON response
5: Manage cookies
6: Work with HTTP headers
7: Handling redirects
8: Routing
9: Template engines
10: Middleware
11: Serving Static Assets with Express
12: Send files to the client
13: Sessions
14: Validating and sanitizing input
15: ▶︎ Handling form data
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