* @link http://www.pradosoft.com/
* @copyright Copyright © 2005-2008 PradoSoft
* @license http://www.pradosoft.com/license/
* @version $Id$
* @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
* error[StatusCode][-LanguageCode].html, and for the latter it is
* exception[-LanguageCode].html, 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 error.html and exception.html 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
*
*
* @author Qiang Xue
* @version $Id$
* @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',$value);
}
/**
* Handles PHP user errors and exceptions.
* This is the event handler responding to the Error event
* raised in {@link TApplication}.
* The method mainly uses appropriate template to display the error/exception.
* It terminates the application immediately after the error is displayed.
* @param mixed sender of the event
* @param mixed event parameter (if the event is raised by TApplication, it refers to the exception instance)
*/
public function handleError($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 Debug
* 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'].' PRADO/'.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 Debug
* 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 "Recursive Error\n";
echo "Recursive Error
\n";
echo "".$exception->__toString()."
\n";
echo "";
}
else
{
error_log("Error happened while processing an existing error:\n".$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 Debug 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'].' PRADO/'.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])));
$source.="".$line."
";
}
else
$source.=htmlspecialchars(sprintf("%04d: %s",$i+1,str_replace("\t",' ',$lines[$i])));
}
return $source;
}
private function addLink($message)
{
$baseUrl='http://www.pradosoft.com/docs/classdoc';
return preg_replace('/\b(T[A-Z]\w+)\b/',"\${1}",$message);
}
}
?>