RESTful routing with PHP

ControllerBase.php

<?php
  $bn = basename($_SERVER['SCRIPT_NAME'], '.php');
  $p = explode('_', $bn);
  $model_name = substr($p[0], 0, -1);
  $model_path = "../models/$model_name.php";
  include_once($model_path);
  include_once('../../config/routes.php');
  $controller_name = $p[0];

  function loadRESTfulView($controllerName, $action, $_options) {
    $path = "../views/$controllerName/$action.php";
    $options = $_options;
    include($path);
  }

  function autoload($class_name) {
    include_once ('../models/' . lcfirst($class_name) . '.php');
  }
  spl_autoload_register('autoload');

  $view_dir = "../views/$model_name";

  // ************************ INTERESTING STUFF STARTS HERE ************************ //

  // Adapted from Rails RESTful routing
  // http://guides.rubyonrails.org/routing.html#crud-verbs-and-actions
  
  // Get current page URL
  $current_path = $_SERVER["REQUEST_URI"];
  // Split current path into components
  $p = explode('/', $current_path);
  array_walk($p, function(&$o) {  // For each component
    // Strip out GET parameters — the stuff after the question mark in a URL like on Google
    $l = strpos($o, '?'); // Get position of question mark
    if ($l)  // If there is a question mark
      $o = substr($o, 0, $l);  // Get part of URL before question mark
  });
  // Ignore the domain — just want the path (part of URL after domain)
  $current_path = $p[1];
  // Create a variable to hold the controller action
  $action = '';
  // Create a variable to hold the id (define -1 to be error)
  $id = -1;
  // Server should return HTML (unless JSON is specified in URL)
  $type = 'html';
  if (isset($p[2])) {  // If there is a second component to the path — only for certain routes
    $t = explode('.', $p[2]); // Second part may include a dot-extension, like .json or .html
    $id = intval($t[0]);  // Get integer value of stuff before the dot, or the whole component if no dot
    if (isset($t[1]))  // If there is a type
      $type = $t[1];  // Set the variable for the type
  }
  if ($id > -1) // If there is an ID
    $current_path = $current_path . '/' . $id;  // Start to build up the path again, after breaking it apart

  // Slug is being ignored here
  // Slug is an optional name after the ID that makes the URL more readable
  // Look at StackOverflow URLs — they include the question as part of the URL
  // But the URLs still work without all that stuff
  // Better for SEO, but not necessary, so we ignore any slug here
  if (preg_match("/^[a-zA-Z]+s$/", $current_path)) {  // Match URL with only one component, ending in 's'
    // Ending in 's' because this part of a route should be plural
    // Note that this doesn't work for really weird plurals (that don't end in 's')
    if ($_SERVER['REQUEST_METHOD'] == 'GET')
      $action = 'index';
    else if ($_SERVER['REQUEST_METHOD'] == 'POST')
      $action = 'create';
  }
  else if (preg_match("/^[a-zA-Z]+\/new$/", $current_path)) { // Match URL with one component and another that says 'new'
    $action = 'new';
  }
  else if ($id > -1) {  // If there is an ID
    if ($_SERVER['REQUEST_METHOD'] == 'GET')
      $action = 'show';
    else if ($_SERVER['REQUEST_METHOD'] == 'PUT')
      $action = 'update';
    else if ($_SERVER['REQUEST_METHOD'] == 'DELETE')
      $action = 'destroy';
  }
  else if ($id > -1 && isset($p[3]) && $p[3] == 'edit') { // If there is an ID and URL has 'edit'
    if ($_SERVER['REQUEST_METHOD'] == 'GET')
      $action = 'edit';
  }

  // At this point, if the URL matches correctly, $action is set to a method name
  // 'index', 'new', 'create', 'show', 'edit', 'update', or 'destroy'
  // Otherwise (if the URL doesn't match anything), $action is blank

  if ($type == 'json')
    header('Content-type: application/json'); // Tell browser that response is in JSON format
  
  if (strlen($action) == 0) {  // Didn't match any RESTful route
    // Have controller custom-handle request with everything that we know
    handle_request($current_path, $_SERVER['REQUEST_METHOD'], array_merge($_GET, $_POST), $type);
  }
  else {
    $params = array_merge($_GET, $_POST);
    $params['action'] = $action;
    $params['type'] = $type;
    if ($id > -1) {
      $params['id'] = $id;
      $action($params);  // Call method by name: http://php.net/manual/en/functions.variable-functions.php
    }
    else
      $action($params);
  }
?>

Well-commented version, original file here:
https://github.com/feifanzhou/Pails/blob/master/app/controllers/ControllerBase.php