Subversion-Projekte lars-tiefland.prado

<?php

/**

 * TErrorHandler class file

 *

 * @author Qiang Xue <qiang.xue@gmail.com>

 * @link http://www.pradosoft.com/

 * @copyright Copyright © 2005-2008 PradoSoft

 * @license http://www.pradosoft.com/license/

 * @version $Id: TErrorHandler.php 2541 2008-10-21 15:05:13Z qiang.xue $

 * @package System.Exceptions

 */

/**

 * TErrorHandler class

 *

 * TErrorHandler handles all PHP user errors and exceptions generated during

 * servicing user requests. It displays these errors using different templates

 * and if possible, using languages preferred by the client user.

 * Note, PHP parsing errors cannot be caught and handled by TErrorHandler.

 *

 * The templates used to format the error output are stored under System.Exceptions.

 * You may choose to use your own templates, should you not like the templates

 * provided by Prado. Simply set {@link setErrorTemplatePath ErrorTemplatePath}

 * to the path (in namespace format) storing your own templates.

 *

 * There are two sets of templates, one for errors to be displayed to client users

 * (called external errors), one for errors to be displayed to system developers

 * (called internal errors). The template file name for the former is

 * <b>error[StatusCode][-LanguageCode].html</b>, and for the latter it is

 * <b>exception[-LanguageCode].html</b>, where StatusCode refers to response status

 * code (e.g. 404, 500) specified when {@link THttpException} is thrown,

 * and LanguageCode is the client user preferred language code (e.g. en, zh, de).

 * The templates <b>error.html</b> and <b>exception.html</b> are default ones

 * that are used if no other appropriate templates are available.

 * Note, these templates are not Prado control templates. They are simply

 * html files with keywords (e.g. %%ErrorMessage%%, %%Version%%)

 * to be replaced with the corresponding information.

 *

 * By default, TErrorHandler is registered with {@link TApplication} as the

 * error handler module. It can be accessed via {@link TApplication::getErrorHandler()}.

 * You seldom need to deal with the error handler directly. It is mainly used

 * by the application object to handle errors.

 *

 * TErrorHandler may be configured in application configuration file as follows

 * <module id="error" class="TErrorHandler" ErrorTemplatePath="System.Exceptions" />

 *

 * @author Qiang Xue <qiang.xue@gmail.com>

 * @version $Id: TErrorHandler.php 2541 2008-10-21 15:05:13Z qiang.xue $

 * @package System.Exceptions

 * @since 3.0

 */

class TErrorHandler extends TModule

{

	/**

	 * error template file basename

	 */

	const ERROR_FILE_NAME='error';

	/**

	 * exception template file basename

	 */

	const EXCEPTION_FILE_NAME='exception';

	/**

	 * number of lines before and after the error line to be displayed in case of an exception

	 */

	const SOURCE_LINES=12;

	/**

	 * @var string error template directory

	 */

	private $_templatePath=null;

	/**

	 * Initializes the module.

	 * This method is required by IModule and is invoked by application.

	 * @param TXmlElement module configuration

	 */

	public function init($config)

	{

		$this->getApplication()->setErrorHandler($this);

	}

	/**

	 * @return string the directory containing error template files.

	 */

	public function getErrorTemplatePath()

	{

		if($this->_templatePath===null)

			$this->_templatePath=Prado::getFrameworkPath().'/Exceptions/templates';

		return $this->_templatePath;

	}

	/**

	 * Sets the path storing all error and exception template files.

	 * The path must be in namespace format, such as System.Exceptions (which is the default).

	 * @param string template path in namespace format

	 * @throws TConfigurationException if the template path is invalid

	 */

	public function setErrorTemplatePath($value)

	{

		if(($templatePath=Prado::getPathOfNamespace($value))!==null && is_dir($templatePath))

			$this->_templatePath=$templatePath;

		else

			throw new TConfigurationException('errorhandler_errortemplatepath_invalid',$value);

	}

	/**

	 * Handles PHP user errors and exceptions.

	 * This is the event handler responding to the <b>Error</b> event

	 * raised in {@link TApplication}.

	 * The method mainly uses appropriate template to display the error/exception.

	 * It terminates the application immediately after the error is displayed.

	 * @param mixed sender of the event

	 * @param mixed event parameter (if the event is raised by TApplication, it refers to the exception instance)

	 */

	public function handleError($sender,$param)

	{

		static $handling=false;

		// We need to restore error and exception handlers,

		// because within error and exception handlers, new errors and exceptions

		// cannot be handled properly by PHP

		restore_error_handler();

		restore_exception_handler();

		// ensure that we do not enter infinite loop of error handling

		if($handling)

			$this->handleRecursiveError($param);

		else

		{

			$handling=true;

			if(($response=$this->getResponse())!==null)

				$response->clear();

			if(!headers_sent())

				header('Content-Type: text/html; charset=UTF-8');

			if($param instanceof THttpException)

				$this->handleExternalError($param->getStatusCode(),$param);

			else if($this->getApplication()->getMode()===TApplicationMode::Debug)

				$this->displayException($param);

			else

				$this->handleExternalError(500,$param);

		}

	}

	/**

	 * Displays error to the client user.

	 * THttpException and errors happened when the application is in <b>Debug</b>

	 * mode will be displayed to the client user.

	 * @param integer response status code

	 * @param Exception exception instance

	 */

	protected function handleExternalError($statusCode,$exception)

	{

		if(!($exception instanceof THttpException))

			error_log($exception->__toString());

		$content=$this->getErrorTemplate($statusCode,$exception);

		$serverAdmin=isset($_SERVER['SERVER_ADMIN'])?$_SERVER['SERVER_ADMIN']:'';

		if($this->getApplication()->getMode()===TApplicationMode::Debug)

			$version=$_SERVER['SERVER_SOFTWARE'].' <a href="http://www.pradosoft.com/">PRADO</a>/'.Prado::getVersion();

		else

			$version='';

		$tokens=array(

			'%%StatusCode%%' => "$statusCode",

			'%%ErrorMessage%%' => htmlspecialchars($exception->getMessage()),

			'%%ServerAdmin%%' => $serverAdmin,

			'%%Version%%' => $version,

			'%%Time%%' => @strftime('%Y-%m-%d %H:%M',time())

		);

		header("HTTP/1.0 $statusCode ".$exception->getMessage());

		echo strtr($content,$tokens);

	}

	/**

	 * Handles error occurs during error handling (called recursive error).

	 * THttpException and errors happened when the application is in <b>Debug</b>

	 * mode will be displayed to the client user.

	 * Error is displayed without using existing template to prevent further errors.

	 * @param Exception exception instance

	 */

	protected function handleRecursiveError($exception)

	{

		if($this->getApplication()->getMode()===TApplicationMode::Debug)

		{

			echo "<html><head><title>Recursive Error</title></head>\n";

			echo "<body><h1>Recursive Error</h1>\n";

			echo "<pre>".$exception->__toString()."</pre>\n";

			echo "</body></html>";

		}

		else

		{

			error_log("Error happened while processing an existing error:\n".$exception->__toString());

			header('HTTP/1.0 500 Internal Error');

		}

	}

	/**

	 * Displays exception information.

	 * Exceptions are displayed with rich context information, including

	 * the call stack and the context source code.

	 * This method is only invoked when application is in <b>Debug</b> mode.

	 * @param Exception exception instance

	 */

	protected function displayException($exception)

	{

		if(php_sapi_name()==='cli')

		{

			echo $exception->getMessage()."\n";

			echo $exception->getTraceAsString();

			return;

		}

		if($exception instanceof TTemplateException)

		{

			$fileName=$exception->getTemplateFile();

			$lines=empty($fileName)?explode("\n",$exception->getTemplateSource()):@file($fileName);

			$source=$this->getSourceCode($lines,$exception->getLineNumber());

			if($fileName==='')

				$fileName='---embedded template---';

			$errorLine=$exception->getLineNumber();

		}

		else

		{

			if(($trace=$this->getExactTrace($exception))!==null)

			{

				$fileName=$trace['file'];

				$errorLine=$trace['line'];

			}

			else

			{

				$fileName=$exception->getFile();

				$errorLine=$exception->getLine();

			}

			$source=$this->getSourceCode(@file($fileName),$errorLine);

		}

		if($this->getApplication()->getMode()===TApplicationMode::Debug)

			$version=$_SERVER['SERVER_SOFTWARE'].' <a href="http://www.pradosoft.com/">PRADO</a>/'.Prado::getVersion();

		else

			$version='';

		$tokens=array(

			'%%ErrorType%%' => get_class($exception),

			'%%ErrorMessage%%' => $this->addLink(htmlspecialchars($exception->getMessage())),

			'%%SourceFile%%' => htmlspecialchars($fileName).' ('.$errorLine.')',

			'%%SourceCode%%' => $source,

			'%%StackTrace%%' => htmlspecialchars($exception->getTraceAsString()),

			'%%Version%%' => $version,

			'%%Time%%' => @strftime('%Y-%m-%d %H:%M',time())

		);

		$content=$this->getExceptionTemplate($exception);

		echo strtr($content,$tokens);

	}

	/**

	 * Retrieves the template used for displaying internal exceptions.

	 * Internal exceptions will be displayed with source code causing the exception.

	 * This occurs when the application is in debug mode.

	 * @param Exception the exception to be displayed

	 * @return string the template content

	 */

	protected function getExceptionTemplate($exception)

	{

		$lang=Prado::getPreferredLanguage();

		$exceptionFile=Prado::getFrameworkPath().'/Exceptions/templates/'.self::EXCEPTION_FILE_NAME.'-'.$lang.'.html';

		if(!is_file($exceptionFile))

			$exceptionFile=Prado::getFrameworkPath().'/Exceptions/templates/'.self::EXCEPTION_FILE_NAME.'.html';

		if(($content=@file_get_contents($exceptionFile))===false)

			die("Unable to open exception template file '$exceptionFile'.");

		return $content;

	}

	/**

	 * Retrieves the template used for displaying external exceptions.

	 * External exceptions are those displayed to end-users. They do not contain

	 * error source code. Therefore, you might want to override this method

	 * to provide your own error template for displaying certain external exceptions.

	 * The following tokens in the template will be replaced with corresponding content:

	 * %%StatusCode%% : the status code of the exception

	 * %%ErrorMessage%% : the error message (HTML encoded).

	 * %%ServerAdmin%% : the server admin information (retrieved from Web server configuration)

	 * %%Version%% : the version information of the Web server.

	 * %%Time%% : the time the exception occurs at

	 *

	 * @param integer status code (such as 404, 500, etc.)

	 * @param Exception the exception to be displayed

	 * @return string the template content

	 */

	protected function getErrorTemplate($statusCode,$exception)

	{

		$base=$this->getErrorTemplatePath().DIRECTORY_SEPARATOR.self::ERROR_FILE_NAME;

		$lang=Prado::getPreferredLanguage();

		if(is_file("$base$statusCode-$lang.html"))

			$errorFile="$base$statusCode-$lang.html";

		else if(is_file("$base$statusCode.html"))

			$errorFile="$base$statusCode.html";

		else if(is_file("$base-$lang.html"))

			$errorFile="$base-$lang.html";

		else

			$errorFile="$base.html";

		if(($content=@file_get_contents($errorFile))===false)

			die("Unable to open error template file '$errorFile'.");

		return $content;

	}

	private function getExactTrace($exception)

	{

		$trace=$exception->getTrace();

		$result=null;

		// if PHP exception, we want to show the 2nd stack level context

		// because the 1st stack level is of little use (it's in error handler)

		if($exception instanceof TPhpErrorException)

			$result=isset($trace[0]['file'])?$trace[0]:$trace[1];

		else if($exception instanceof TInvalidOperationException)

		{

			// in case of getter or setter error, find out the exact file and row

			if(($result=$this->getPropertyAccessTrace($trace,'__get'))===null)

				$result=$this->getPropertyAccessTrace($trace,'__set');

		}

		if($result!==null && strpos($result['file'],': eval()\'d code')!==false)

			return null;

		return $result;

	}

	private function getPropertyAccessTrace($trace,$pattern)

	{

		$result=null;

		foreach($trace as $t)

		{

			if(isset($t['function']) && $t['function']===$pattern)

				$result=$t;

			else

				break;

		}

		return $result;

	}

	private function getSourceCode($lines,$errorLine)

	{

		$beginLine=$errorLine-self::SOURCE_LINES>=0?$errorLine-self::SOURCE_LINES:0;

		$endLine=$errorLine+self::SOURCE_LINES<=count($lines)?$errorLine+self::SOURCE_LINES:count($lines);

		$source='';

		for($i=$beginLine;$i<$endLine;++$i)

		{

			if($i===$errorLine-1)

			{

				$line=htmlspecialchars(sprintf("%04d: %s",$i+1,str_replace("\t",'    ',$lines[$i])));

				$source.="<div class=\"error\">".$line."</div>";

			}

			else

				$source.=htmlspecialchars(sprintf("%04d: %s",$i+1,str_replace("\t",'    ',$lines[$i])));

		}

		return $source;

	}

	private function addLink($message)

	{

		$baseUrl='http://www.pradosoft.com/docs/classdoc';

		return preg_replace('/\b(T[A-Z]\w+)\b/',"<a href=\"$baseUrl/\${1}\" target=\"_blank\">\${1}</a>",$message);

	}

}