/**

*

* @package phpBB3

* @version $Id: index.php 8479 2008-03-29 00:22:48Z naderman $

* @copyright (c) 2007 phpBB Group

* @license http://opensource.org/licenses/gpl-license.php GNU Public License

*

*/

/**

* @ignore

*/

if (!defined('IN_PHPBB'))

{

	exit;

}

/**

* phpBB Hook Class

* @package phpBB3

*/

class phpbb_hook

{

	/**

	* Registered hooks

	*/

	var $hooks = array();

	/**

	* Results returned by functions called

	*/

	var $hook_result = array();

	/**

	* internal pointer

	*/

	var $current_hook = NULL;

	/**

	* Initialize hook class.

	*

	* @param array $valid_hooks array containing the hookable functions/methods

	*/

	function phpbb_hook($valid_hooks)

	{

		foreach ($valid_hooks as $_null => $method)

		{

			$this->add_hook($method);

		}

		if (function_exists('phpbb_hook_register'))

		{

			phpbb_hook_register($this);

		}

	}

	/**

	* Register function/method to be called within hook

	* This function is normally called by the modification/application to attach/register the functions.

	*

	* @param mixed $definition Declaring function (with __FUNCTION__) or class with array(__CLASS__, __FUNCTION__)

	* @param mixed $hook The replacement function/method to be called. Passing function name or array with object/class definition

	* @param string $mode Specify the priority/chain mode. 'normal' -> hook gets appended to the chain. 'standalone' -> only the specified hook gets called - later hooks are not able to overwrite this (E_NOTICE is triggered then). 'first' -> hook is called as the first one within the chain. 'last' -> hook is called as the last one within the chain.

	*/

	function register($definition, $hook, $mode = 'normal')

	{

		$class = (!is_array($definition)) ? '__global' : $definition[0];

		$function = (!is_array($definition)) ? $definition : $definition[1];

		// Method able to be hooked?

		if (isset($this->hooks[$class][$function]))

		{

			switch ($mode)

			{

				case 'standalone':

					if (!isset($this->hooks[$class][$function]['standalone']))

					{

						$this->hooks[$class][$function] = array('standalone' => $hook);

					}

					else

					{

						trigger_error('Hook not able to be called standalone, previous hook already standalone.', E_NOTICE);

					}

				break;

				case 'first':

				case 'last':

					$this->hooks[$class][$function][$mode][] = $hook;

				break;

				case 'normal':

				default:

					$this->hooks[$class][$function]['normal'][] = $hook;

				break;

			}

		}

	}

	/**

	* Calling all functions/methods attached to a specified hook.

	* Called by the function allowing hooks...

	*

	* @param mixed $definition Declaring function (with __FUNCTION__) or class with array(__CLASS__, __FUNCTION__)

	* @return bool False if no hook got executed, true otherwise

	*/

	function call_hook($definition)

	{

		$class = (!is_array($definition)) ? '__global' : $definition[0];

		$function = (!is_array($definition)) ? $definition : $definition[1];

		if (!empty($this->hooks[$class][$function]))

		{

			// Developer tries to call a hooked function within the hooked function...

			if ($this->current_hook !== NULL && $this->current_hook['class'] === $class && $this->current_hook['function'] === $function)

			{

				return false;

			}

			// Call the hook with the arguments attached and store result

			$arguments = func_get_args();

			$this->current_hook = array('class' => $class, 'function' => $function);

			$arguments[0] = &$this;

			// Call the hook chain...

			if (isset($this->hooks[$class][$function]['standalone']))

			{

				$this->hook_result[$class][$function] = call_user_func_array($this->hooks[$class][$function]['standalone'], $arguments);

			}

			else

			{

				foreach (array('first', 'normal', 'last') as $mode)

				{

					if (!isset($this->hooks[$class][$function][$mode]))

					{

						continue;

					}

					foreach ($this->hooks[$class][$function][$mode] as $hook)

					{

						$this->hook_result[$class][$function] = call_user_func_array($hook, $arguments);

					}

				}

			}

			$this->current_hook = NULL;

			return true;

		}

		$this->current_hook = NULL;

		return false;

	}

	/**

	* Get result from previously called functions/methods for the same hook

	*

	* @param mixed $definition Declaring function (with __FUNCTION__) or class with array(__CLASS__, __FUNCTION__)

	* @return mixed False if nothing returned if there is no result, else array('result' => ... )

	*/

	function previous_hook_result($definition)

	{

		$class = (!is_array($definition)) ? '__global' : $definition[0];

		$function = (!is_array($definition)) ? $definition : $definition[1];

		if (!empty($this->hooks[$class][$function]) && isset($this->hook_result[$class][$function]))

		{

			return array('result' => $this->hook_result[$class][$function]);

		}

		return false;

	}

	/**

	* Check if the called functions/methods returned something.

	*

	* @param mixed $definition Declaring function (with __FUNCTION__) or class with array(__CLASS__, __FUNCTION__)

	* @return bool True if results are there, false if not

	*/

	function hook_return($definition)

	{

		$class = (!is_array($definition)) ? '__global' : $definition[0];

		$function = (!is_array($definition)) ? $definition : $definition[1];

		if (!empty($this->hooks[$class][$function]) && isset($this->hook_result[$class][$function]))

		{

			return true;

		}

		return false;

	}

	/**

	* Give actual result from called functions/methods back.

	*

	* @param mixed $definition Declaring function (with __FUNCTION__) or class with array(__CLASS__, __FUNCTION__)

	* @return mixed The result

	*/

	function hook_return_result($definition)

	{

		$class = (!is_array($definition)) ? '__global' : $definition[0];

		$function = (!is_array($definition)) ? $definition : $definition[1];

		if (!empty($this->hooks[$class][$function]) && isset($this->hook_result[$class][$function]))

		{

			$result = $this->hook_result[$class][$function];

			unset($this->hook_result[$class][$function]);

			return $result;

		}

		return;

	}

	/**

	* Add new function to the allowed hooks.

	*

	* @param mixed $definition Declaring function (with __FUNCTION__) or class with array(__CLASS__, __FUNCTION__)

	*/

	function add_hook($definition)

	{

		if (!is_array($definition))

		{

			$definition = array('__global', $definition);

		}

		$this->hooks[$definition[0]][$definition[1]] = array();

	}

	/**

	* Remove function from the allowed hooks.

	*

	* @param mixed $definition Declaring function (with __FUNCTION__) or class with array(__CLASS__, __FUNCTION__)

	*/

	function remove_hook($definition)

	{

		$class = (!is_array($definition)) ? '__global' : $definition[0];

		$function = (!is_array($definition)) ? $definition : $definition[1];

		if (isset($this->hooks[$class][$function]))

		{

			unset($this->hooks[$class][$function]);

			if (isset($this->hook_result[$class][$function]))

			{

				unset($this->hook_result[$class][$function]);

			}

		}

	}

}

?>