express-urlrewrite

What is express-urlrewrite?

The express-urlrewrite package is a middleware for Express.js that allows you to rewrite URLs based on specified patterns. This can be useful for redirecting traffic, simplifying URLs, or handling legacy URL structures.

What are express-urlrewrite's main functionalities?

Simple URL Rewriting

This feature allows you to rewrite a simple URL from '/old-path' to '/new-path'. When a user visits '/old-path', they will be served the content from '/new-path'.

const express = require('express');
const rewrite = require('express-urlrewrite');
const app = express();

app.use(rewrite('/old-path', '/new-path'));

app.get('/new-path', (req, res) => {
  res.send('This is the new path');
});

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

Pattern-based URL Rewriting

This feature allows you to rewrite URLs based on patterns. In this example, any URL matching '/user/:id' will be rewritten to '/profile/:id', where ':id' is a dynamic parameter.

const express = require('express');
const rewrite = require('express-urlrewrite');
const app = express();

app.use(rewrite('/user/:id', '/profile/:id'));

app.get('/profile/:id', (req, res) => {
  res.send(`Profile ID: ${req.params.id}`);
});

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

Regular Expression URL Rewriting

This feature allows you to use regular expressions for URL rewriting. In this example, any URL matching the pattern '/old-<number>' will be rewritten to '/new/<number>'.

const express = require('express');
const rewrite = require('express-urlrewrite');
const app = express();

app.use(rewrite(/^\/old-(\d+)$/, '/new/$1'));

app.get('/new/:id', (req, res) => {
  res.send(`New ID: ${req.params.id}`);
});

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

Other packages similar to express-urlrewrite

connect-modrewrite

The connect-modrewrite package provides similar functionality to express-urlrewrite, allowing you to rewrite URLs using mod_rewrite syntax. It is more flexible in terms of complex rewrite rules but may have a steeper learning curve.

express-rewrite

The express-rewrite package is another alternative for URL rewriting in Express.js. It offers similar features but with a different API. It is less popular than express-urlrewrite but can be a good alternative for specific use cases.

express-redirect

The express-redirect package focuses on URL redirection rather than rewriting. It allows you to easily set up HTTP redirects in your Express.js application. While it doesn't offer the same level of URL manipulation as express-urlrewrite, it is useful for simple redirection needs.

README

express-urlrewrite

URL rewrite middleware for express.

Examples

Rewrite using a regular expression, rewriting /i123 to /items/123.

app.use(rewrite(/^\/i(\w+)/, '/items/$1'));

Rewrite using route parameters, references may be named or numeric. For example rewrite /foo..bar to /commits/foo/to/bar:

app.use(rewrite('/:src..:dst', '/commits/$1/to/$2'));
app.use(rewrite('/:src..:dst', '/commits/:src/to/:dst'));

You may also use the wildcard * to soak up several segments, for example /js/vendor/jquery.js would become /public/assets/js/vendor/jquery.js:

app.use(rewrite('/js/*', '/public/assets/js/$1'));

In the above examples, the original query string (if any) is left untouched. The regular expression is applied to the full url, so the query string can be modified as well:

app.use(rewrite('/file\\?param=:param', '/file/:param'))

The query string delimiter (?) must be escaped for the regular expression to work.

New in version 1.1

app.use(rewrite('/path', '/anotherpath?param=some'))

now updates req.query, so req.query.param == 'some'.

New in version 1.2

rewrite can be used as a route middleware as in

app.get('/route/:var', rewrite('/rewritten/:var'));

app.get('/rewritten/:var', someMw);

Instead of passing control to next middleware, it passes control to next route.

Debugging

Set environment variable DEBUG=express-urlrewrite