Swift.php

<?php

/*
 * This file is part of SwiftMailer.
 * (c) 2004-2009 Chris Corbyn
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

/**
 * General utility class in Swift Mailer, not to be instantiated.
 * 
 * @package Swift
 * 
 * @author Chris Corbyn
 */
abstract class Swift
{
  
  static $initialized = false;
  static $inits = array();
  
  /** Swift Mailer Version number generated during dist release process */
  const VERSION = '4.2.0';
  
  /**
   * Registers an initializer callable that will be called the first time
   * a SwiftMailer class is autoloaded.
   *
   * This enables you to tweak the default configuration in a lazy way.
   *
   * @param mixed $callable A valid PHP callable that will be called when autoloading the first Swift class
   */
  public static function init($callable)
  {
    self::$inits[] = $callable;
  }
  
  /**
   * Internal autoloader for spl_autoload_register().
   * 
   * @param string $class
   */
  public static function autoload($class)
  {
    //Don't interfere with other autoloaders
    if (0 !== strpos($class, 'Swift_'))
    {
      return;
    }

    $path = dirname(__FILE__).'/'.str_replace('_', '/', $class).'.php';

    if (!file_exists($path))
    {
      return;
    }

    require $path;

    if (self::$inits && !self::$initialized)
    {
      self::$initialized = true;
      foreach (self::$inits as $init)
      {
        call_user_func($init);
      }
    }
  }
  
  /**
   * Configure autoloading using Swift Mailer.
   * 
   * This is designed to play nicely with other autoloaders.
   *
   * @param mixed $callable A valid PHP callable that will be called when autoloading the first Swift class
   */
  public static function registerAutoload($callable = null)
  {
    if (null !== $callable)
    {
      self::$inits[] = $callable;
    }
    spl_autoload_register(array('Swift', 'autoload'));
  }
  
}