Pretty URLs in PHP frameworks

This is usually done by routing all requests to a single entry point (a file that executes different code based on the request) with a rule like:

# Redirect everything that doesn't match a directory or file to index.phpRewriteCond %{REQUEST_FILENAME} !-dRewriteCond %{REQUEST_FILENAME} !-fRewriteRule .* index.php [L]

This file then compares the request ($_SERVER["REQUEST_URI"]) against a list of routes - a mapping of a pattern matching the request to a controller action (in MVC applications) or another path of execution. Frameworks often include a route that can infer the controller and action from the request itself, as a backup route.

A small, simplified example:

<?php// Define a couple of simple actionsclass Home {    public function GET() { return 'Homepage'; }}class About {    public function GET() { return 'About page'; }}// Mapping of request pattern (URL) to action classes (above)$routes = array(    '/' => 'Home',    '/about' => 'About');// Match the request to a route (find the first matching URL in routes)$request = '/' . trim($_SERVER['REQUEST_URI'], '/');$route = null;foreach ($routes as $pattern => $class) {    if ($pattern == $request) {        $route = $class;        break;    }}// If no route matched, or class for route not found (404)if (is_null($route) || !class_exists($route)) {    header('HTTP/1.1 404 Not Found');    echo 'Page not found';    exit(1);}// If method not found in action class, send a 405 (e.g. Home::POST())if (!method_exists($route, $_SERVER["REQUEST_METHOD"])) {    header('HTTP/1.1 405 Method not allowed');    echo 'Method not allowed';    exit(1);}// Otherwise, return the result of the action$action = new $route;$result = call_user_func(array($action, $_SERVER["REQUEST_METHOD"]));echo $result;

Combined with the first configuration, this is a simple script that will allow you to use URLs like domain.com/about. Hope this helps you make sense of what's going on here.