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system/core/Hooks.php

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+<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP 5.1.6 or newer
+ *
+ * @package		CodeIgniter
+ * @author		ExpressionEngine Dev Team
+ * @copyright	Copyright (c) 2008 - 2011, EllisLab, Inc.
+ * @license		http://codeigniter.com/user_guide/license.html
+ * @link		http://codeigniter.com
+ * @since		Version 1.0
+ * @filesource
+ */
+
+// ------------------------------------------------------------------------
+
+/**
+ * CodeIgniter Hooks Class
+ *
+ * Provides a mechanism to extend the base system without hacking.
+ *
+ * @package		CodeIgniter
+ * @subpackage	Libraries
+ * @category	Libraries
+ * @author		ExpressionEngine Dev Team
+ * @link		http://codeigniter.com/user_guide/libraries/encryption.html
+ */
+class CI_Hooks {
+
+	/**
+	 * Determines wether hooks are enabled
+	 *
+	 * @var bool
+	 */
+	var $enabled		= FALSE;
+	/**
+	 * List of all hooks set in config/hooks.php
+	 *
+	 * @var array
+	 */
+	var $hooks			= array();
+	/**
+	 * Determines wether hook is in progress, used to prevent infinte loops
+	 *
+	 * @var bool
+	 */
+	var $in_progress	= FALSE;
+
+	/**
+	 * Constructor
+	 *
+	 */
+	function __construct()
+	{
+		$this->_initialize();
+		log_message('debug', "Hooks Class Initialized");
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Initialize the Hooks Preferences
+	 *
+	 * @access	private
+	 * @return	void
+	 */
+	function _initialize()
+	{
+		$CFG =& load_class('Config', 'core');
+
+		// If hooks are not enabled in the config file
+		// there is nothing else to do
+
+		if ($CFG->item('enable_hooks') == FALSE)
+		{
+			return;
+		}
+
+		// Grab the "hooks" definition file.
+		// If there are no hooks, we're done.
+
+		if (defined('ENVIRONMENT') AND is_file(APPPATH.'config/'.ENVIRONMENT.'/hooks.php'))
+		{
+		    include(APPPATH.'config/'.ENVIRONMENT.'/hooks.php');
+		}
+		elseif (is_file(APPPATH.'config/hooks.php'))
+		{
+			include(APPPATH.'config/hooks.php');
+		}
+
+
+		if ( ! isset($hook) OR ! is_array($hook))
+		{
+			return;
+		}
+
+		$this->hooks =& $hook;
+		$this->enabled = TRUE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Call Hook
+	 *
+	 * Calls a particular hook
+	 *
+	 * @access	private
+	 * @param	string	the hook name
+	 * @return	mixed
+	 */
+	function _call_hook($which = '')
+	{
+		if ( ! $this->enabled OR ! isset($this->hooks[$which]))
+		{
+			return FALSE;
+		}
+
+		if (isset($this->hooks[$which][0]) AND is_array($this->hooks[$which][0]))
+		{
+			foreach ($this->hooks[$which] as $val)
+			{
+				$this->_run_hook($val);
+			}
+		}
+		else
+		{
+			$this->_run_hook($this->hooks[$which]);
+		}
+
+		return TRUE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Run Hook
+	 *
+	 * Runs a particular hook
+	 *
+	 * @access	private
+	 * @param	array	the hook details
+	 * @return	bool
+	 */
+	function _run_hook($data)
+	{
+		if ( ! is_array($data))
+		{
+			return FALSE;
+		}
+
+		// -----------------------------------
+		// Safety - Prevents run-away loops
+		// -----------------------------------
+
+		// If the script being called happens to have the same
+		// hook call within it a loop can happen
+
+		if ($this->in_progress == TRUE)
+		{
+			return;
+		}
+
+		// -----------------------------------
+		// Set file path
+		// -----------------------------------
+
+		if ( ! isset($data['filepath']) OR ! isset($data['filename']))
+		{
+			return FALSE;
+		}
+
+		$filepath = APPPATH.$data['filepath'].'/'.$data['filename'];
+
+		if ( ! file_exists($filepath))
+		{
+			return FALSE;
+		}
+
+		// -----------------------------------
+		// Set class/function name
+		// -----------------------------------
+
+		$class		= FALSE;
+		$function	= FALSE;
+		$params		= '';
+
+		if (isset($data['class']) AND $data['class'] != '')
+		{
+			$class = $data['class'];
+		}
+
+		if (isset($data['function']))
+		{
+			$function = $data['function'];
+		}
+
+		if (isset($data['params']))
+		{
+			$params = $data['params'];
+		}
+
+		if ($class === FALSE AND $function === FALSE)
+		{
+			return FALSE;
+		}
+
+		// -----------------------------------
+		// Set the in_progress flag
+		// -----------------------------------
+
+		$this->in_progress = TRUE;
+
+		// -----------------------------------
+		// Call the requested class and/or function
+		// -----------------------------------
+
+		if ($class !== FALSE)
+		{
+			if ( ! class_exists($class))
+			{
+				require($filepath);
+			}
+
+			$HOOK = new $class;
+			$HOOK->$function($params);
+		}
+		else
+		{
+			if ( ! function_exists($function))
+			{
+				require($filepath);
+			}
+
+			$function($params);
+		}
+
+		$this->in_progress = FALSE;
+		return TRUE;
+	}
+
+}
+
+// END CI_Hooks class
+
+/* End of file Hooks.php */
+/* Location: ./system/core/Hooks.php */