3. What do we do with legacy code? We refactor! Refactoring is safely changing the implementation of code without changing the behavior of code.

8. The simplest view class class View { protected static $VIEW_PATH = '/wherever/views/'; public function assign($name, $value) { return $this->$name = $value; } public function render($filename) { $filename = self::$VIEW_PATH . $filename; if (is_file($filename)) { ob_start(); include($filename); return ob_get_clean(); } } }

15. Alternative control structures <?php if ($foo): ?> ... <?php endif; ?> <?php foreach ($this as $that): ?> ... <?php endforeach; ?>

26. Using nested requires instead of function calls <?php require_once('db_setup_inc.php'); require_once('account_auth_inc.php'); require_once('i18n_inc.php'); echo ' <h1>Orders for account #' . $account_id . '</h1>'; require('get_all_orders_inc.php'); ...

31. account_auth_inc.php <?php $auth_token = $_COOKIE['token'] ; if ($auth_token) { $acct_id = $db ->GetOne('SELECT acct_id FROM logins WHERE auth_token = ?', array($auth_token)); } if ($acct_id) { $acct = new Account($acct_id); } else { $acct = null; } $_COOKIE['token'] = gen_new_token($auth_token);

33. Function-wrapped <?php function account_auth($db, $auth_token) { if ( $auth_token ) { $acct_id = $db->GetOne('SELECT acct_id FROM logins WHERE auth_token = ?', array($auth_token)); } if ($acct_id) { $acct = new Account($acct_id); } else { $acct = null; } return array($acct, gen_new_token($auth_token)); } list($acct, $_COOKIE['token']) = account_auth($db, $_COOKIE['token']);

35. Moved token handling to Account <?php function account_auth($db, $auth_token) { // Instead of null, we now return an unloaded Account. $acct = new Account(); if ($auth_token) { // SQL code from before $acct->loadFromToken($auth_token); // Token generation and cookie setting $acct->genNewToken($auth_token); } return $acct; } $acct = account_auth($db, $_COOKIE['token']);

37. Global variables everywhere <?php $account_id = $_POST['acct_id']; $account = new Account($account_id); function getPurchases() { global $account; global $database; ... } function getLanguage() { global $account; global $database; global $i18n; ... }

43. Parameterizing globals <?php $account_id = $_POST['acct_id']; $account = new Account( $database , $account_id); function getPurchases( $account ) { global $account; global $database; ... } function getLanguage( $account, $i18n ) { global $account; global $database; global $i18n; ... }