<?php
// $Id: errorhandler.php,v 1.1 2004/09/09 05:14:50 onokazu Exp $
//  ------------------------------------------------------------------------ //
//                XOOPS - PHP Content Management System                      //
//                    Copyright (c) 2000 XOOPS.org                           //
//                       <http://www.xoops.org/>                             //
//  ------------------------------------------------------------------------ //
//  This program is free software; you can redistribute it and/or modify     //
//  it under the terms of the GNU General Public License as published by     //
//  the Free Software Foundation; either version 2 of the License, or        //
//  (at your option) any later version.                                      //
//                                                                           //
//  You may not change or alter any portion of this comment or credits       //
//  of supporting developers from this source code or any supporting         //
//  source code which is considered copyrighted (c) material of the          //
//  original comment or credit authors.                                      //
//                                                                           //
//  This program is distributed in the hope that it will be useful,          //
//  but WITHOUT ANY WARRANTY; without even the implied warranty of           //
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the            //
//  GNU General Public License for more details.                             //
//                                                                           //
//  You should have received a copy of the GNU General Public License        //
//  along with this program; if not, write to the Free Software              //
//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA //
//  ------------------------------------------------------------------------ //

/**
 * Error handler class
 *
 * @author Michael van Dam
 */
class XoopsErrorHandler
{
	/**
	 * List of errors
	 * 
	 * @var array 
	 * @access private 
	 */
	var $_errors = array();

	/**
	 * Show error messages?
	 *
	 * @var boolean
	 * @access private
	 */
	var $_showErrors = false;

	/**
	 * Was there a fatal error (E_USER_ERROR)
	 *
	 * @var boolean
	 * @access private
	 */
	var $_isFatal = false;

	/**
	 * Constructor
	 *
	 * Registers the error handler and shutdown functions.  NOTE: when
	 * registering an error handler, the setting or 'error_reporting' is
	 * ignored and *everything* is trapped.
	 */
	function XoopsErrorHandler()
	{
		set_error_handler('XoopsErrorHandler_HandleError');
		register_shutdown_function('XoopsErrorHandler_Shutdown'); 
	}

	/**
	 * Get the (singleton) instance of the error handler
	 *
	 * @access public
	 */
	function &getInstance()
	{
		static $instance = null;
		if (empty($instance)) {
			$instance = new XoopsErrorHandler;
		}
		return $instance;
	}

	/**
	 * Activate the error handler
	 *
	 * @access public 
	 * @param boolean $showErrors True if debug mode is on
	 * @return void 
	 */
	function activate($showErrors=false)
	{ 
		$this->_showErrors = $showErrors;
	} 

	/**
	 * Handle an error
	 * 
	 * @param array $error Associative array containing error info
	 * @access public 
	 * @return void 
	 */
	function handleError($error)
	{
		if (($error['errno'] & error_reporting()) != $error['errno']) {
			return;
		}
		$this->_errors[] = $error;
		if ($error['errno'] == E_USER_ERROR) {
			$this->_isFatal = true;
			exit();
		}
	} 

	/**
	 * Render the list of errors
	 *
	 * NOTE: Unfortunately PHP 'fatal' and 'parse' errors are not trappable.
	 * If the server has 'display_errors Off', then the result will be a
	 * blank page.  It would be nice to print a message 'This page cannot
	 * be displayed', but there seems to be no way to print this only when
	 * exiting due to a fatal error rather than normal end of page.
	 *
	 * Thus, 'trigger_error' should be used to trap problems early and
	 * display a meaningful message before a PHP fatal or parse error can
	 * occur.
	 * 
	 * @TODO Use CSS
	 * @TODO Use language? or allow customized message?
	 *
	 * @access public 
	 * @return void 
	 */
	function renderErrors()
	{
		$output = '';
		if ($this->_isFatal) {
			$output .= 'This page cannot be displayed due to an internal error.<br/><br/>';
			$output .= 'If you are the administrator of this site, please visit the <a href="http://wiki.xoops.org/wakka.php?wakka=TroubleshootingBlankPage">Xoops Troubleshooting Page</a> for assistance.<br/><br/>';
		}
		if (!$this->_showErrors || empty($this->_errors)) {
			return $output;
		}

		foreach( $this->_errors as $error )
		{
			switch ( $error['errno'] )
			{
				case E_USER_NOTICE:
					$output .= "Notice [Xoops]: ";
					break;
				case E_USER_WARNING:
					$output .= "Warning [Xoops]: ";
					break;
				case E_USER_ERROR:
					$output .= "Error [Xoops]: ";
					break;
				case E_NOTICE:
					$output .= "Notice [PHP]: ";
					break;
				case E_WARNING:
					$output .= "Warning [PHP]: ";
					break;
				default:
					$output .= "Unknown Condition [" . $error['errno'] . "]: ";
			} 
			$output .= sprintf( "%s in file %s line %s<br>\n", $error['errstr'], $error['errfile'], $error['errline'] );
		} 
		return $output;
	} 

} 

/**
 * User-defined error handler (called from 'trigger_error')
 * 
 * NOTE: Some recent versions of PHP have a 5th parameter, &$p_ErrContext
 * which is an associative array of all variables defined in scope in which
 * error occurred.  We cannot support this, for compatibility with older PHP.
 * 
 * @access public 
 * @param int $errNo Type of error
 * @param string $errStr Error message
 * @param string $errFile File in which error occurred
 * @param int $errLine Line number on which error occurred
 * @return void 
 */
function XoopsErrorHandler_HandleError($errNo, $errStr, $errFile, $errLine)
{ 
	// NOTE: we only store relative pathnames
	$new_error = array( 
		'errno' => $errNo,
		'errstr' => $errStr,
		'errfile' => preg_replace("|^" . XOOPS_ROOT_PATH . "/|", '', $errFile),
		'errline' => $errLine 
		);
	$error_handler =& XoopsErrorHandler::getInstance();
	$error_handler->handleError($new_error);
} 

/**
 * User-defined shutdown function (called from 'exit')
 * 
 * @access public 
 * @return void 
 */
function XoopsErrorHandler_Shutdown()
{
	$error_handler =& XoopsErrorHandler::getInstance();
	echo $error_handler->renderErrors();
} 

?>
