YII 类库手册

protected function argumentsToString($args)
{
    $count=0;

    $isAssoc=$args!==array_values($args);

    foreach($args as $key => $value)
    {
        $count++;
        if($count>=5)
        {
            if($count>5)
                unset($args[$key]);
            else
                $args[$key]='...';
            continue;
        }

        if(is_object($value))
            $args[$key] = get_class($value);
        else if(is_bool($value))
            $args[$key] = $value ? 'true' : 'false';
        else if(is_string($value))
        {
            if(strlen($value)>64)
                $args[$key] = '"'.substr($value,0,64).'..."';
            else
                $args[$key] = '"'.$value.'"';
        }
        else if(is_array($value))
            $args[$key] = 'array('.$this->argumentsToString($value).')';
        else if($value===null)
            $args[$key] = 'null';
        else if(is_resource($value))
            $args[$key] = 'resource';

        if(is_string($key))
        {
            $args[$key] = '"'.$key.'" => '.$args[$key];
        }
        else if($isAssoc)
        {
            $args[$key] = $key.' => '.$args[$key];
        }
    }
    $out = implode(", ", $args);

    return $out;
}

public function getError()
{
    return $this->_error;
}

protected function getExactTrace($exception)
{
    $traces=$exception->getTrace();

    foreach($traces as $trace)
    {
        // property access exception
        if(isset($trace['function']) && ($trace['function']==='__get' || $trace['function']==='__set'))
            return $trace;
    }
    return null;
}

protected function getVersionInfo()
{
    if(YII_DEBUG)
    {
        $version='<a href="http://www.yiiframework.com/">Yii Framework</a>/'.Yii::getVersion();
        if(isset($_SERVER['SERVER_SOFTWARE']))
            $version=$_SERVER['SERVER_SOFTWARE'].' '.$version;
    }
    else
        $version='';
    return $version;
}

protected function getViewFile($view,$code)
{
    $viewPaths=array(
        Yii::app()->getTheme()===null ? null :  Yii::app()->getTheme()->getSystemViewPath(),
        Yii::app() instanceof CWebApplication ? Yii::app()->getSystemViewPath() : null,
        YII_PATH.DIRECTORY_SEPARATOR.'views',
    );

    foreach($viewPaths as $i=>$viewPath)
    {
        if($viewPath!==null)
        {
             $viewFile=$this->getViewFileInternal($viewPath,$view,$code,$i===2?'en_us':null);
             if(is_file($viewFile))
                  return $viewFile;
        }
    }
}

protected function getViewFileInternal($viewPath,$view,$code,$srcLanguage=null)
{
    $app=Yii::app();
    if($view==='error')
    {
        $viewFile=$app->findLocalizedFile($viewPath.DIRECTORY_SEPARATOR."error{$code}.php",$srcLanguage);
        if(!is_file($viewFile))
            $viewFile=$app->findLocalizedFile($viewPath.DIRECTORY_SEPARATOR.'error.php',$srcLanguage);
    }
    else
        $viewFile=$viewPath.DIRECTORY_SEPARATOR."exception.php";
    return $viewFile;
}

public function handle($event)
{
    // set event as handled to prevent it from being handled by other event handlers
    $event->handled=true;

    if($this->discardOutput)
    {
        // the following manual level counting is to deal with zlib.output_compression set to On
        for($level=ob_get_level();$level>0;--$level)
        {
            @ob_end_clean();
        }
    }

    if($event instanceof CExceptionEvent)
        $this->handleException($event->exception);
    else // CErrorEvent
        $this->handleError($event);
}

protected function handleError($event)
{
    $trace=debug_backtrace();
    // skip the first 3 stacks as they do not tell the error position
    if(count($trace)>3)
        $trace=array_slice($trace,3);
    $traceString='';
    foreach($trace as $i=>$t)
    {
        if(!isset($t['file']))
            $trace[$i]['file']='unknown';

        if(!isset($t['line']))
            $trace[$i]['line']=0;

        if(!isset($t['function']))
            $trace[$i]['function']='unknown';

        $traceString.="#$i {$trace[$i]['file']}({$trace[$i]['line']}): ";
        if(isset($t['object']) && is_object($t['object']))
            $traceString.=get_class($t['object']).'->';
        $traceString.="{$trace[$i]['function']}()\n";

        unset($trace[$i]['object']);
    }

    $app=Yii::app();
    if($app instanceof CWebApplication)
    {
        switch($event->code)
        {
            case E_WARNING:
                $type = 'PHP warning';
                break;
            case E_NOTICE:
                $type = 'PHP notice';
                break;
            case E_USER_ERROR:
                $type = 'User error';
                break;
            case E_USER_WARNING:
                $type = 'User warning';
                break;
            case E_USER_NOTICE:
                $type = 'User notice';
                break;
            case E_RECOVERABLE_ERROR:
                $type = 'Recoverable error';
                break;
            default:
                $type = 'PHP error';
        }
        $this->_error=$data=array(
            'code'=>500,
            'type'=>$type,
            'message'=>$event->message,
            'file'=>$event->file,
            'line'=>$event->line,
            'trace'=>$traceString,
            'traces'=>$trace,
        );
        if(!headers_sent())
            header("HTTP/1.0 500 PHP Error");
        if($this->isAjaxRequest())
            $app->displayError($event->code,$event->message,$event->file,$event->line);
        else if(YII_DEBUG)
            $this->render('exception',$data);
        else
            $this->render('error',$data);
    }
    else
        $app->displayError($event->code,$event->message,$event->file,$event->line);
}

protected function handleException($exception)
{
    $app=Yii::app();
    if($app instanceof CWebApplication)
    {
        if(($trace=$this->getExactTrace($exception))===null)
        {
            $fileName=$exception->getFile();
            $errorLine=$exception->getLine();
        }
        else
        {
            $fileName=$trace['file'];
            $errorLine=$trace['line'];
        }

        $trace = $exception->getTrace();

        foreach($trace as $i=>$t)
        {
            if(!isset($t['file']))
                $trace[$i]['file']='unknown';

            if(!isset($t['line']))
                $trace[$i]['line']=0;

            if(!isset($t['function']))
                $trace[$i]['function']='unknown';

            unset($trace[$i]['object']);
        }

        $this->_error=$data=array(
            'code'=>($exception instanceof CHttpException)?$exception->statusCode:500,
            'type'=>get_class($exception),
            'errorCode'=>$exception->getCode(),
            'message'=>$exception->getMessage(),
            'file'=>$fileName,
            'line'=>$errorLine,
            'trace'=>$exception->getTraceAsString(),
            'traces'=>$trace,
        );

        if(!headers_sent())
            header("HTTP/1.0 {$data['code']} ".get_class($exception));

        if($exception instanceof CHttpException || !YII_DEBUG)
            $this->render('error',$data);
        else
        {
            if($this->isAjaxRequest())
                $app->displayException($exception);
            else
                $this->render('exception',$data);
        }
    }
    else
        $app->displayException($exception);
}

protected function isAjaxRequest()
{
    return isset($_SERVER['HTTP_X_REQUESTED_WITH']) && $_SERVER['HTTP_X_REQUESTED_WITH']==='XMLHttpRequest';
}

protected function isCoreCode($trace)
{
    if(isset($trace['file']))
    {
        $systemPath=realpath(dirname(__FILE__).'/..');
        return $trace['file']==='unknown' || strpos(realpath($trace['file']),$systemPath.DIRECTORY_SEPARATOR)===0;
    }
    return false;
}

protected function render($view,$data)
{
    if($view==='error' && $this->errorAction!==null)
        Yii::app()->runController($this->errorAction);
    else
    {
        // additional information to be passed to view
        $data['version']=$this->getVersionInfo();
        $data['time']=time();
        $data['admin']=$this->adminInfo;
        include($this->getViewFile($view,$data['code']));
    }
}

protected function renderSourceCode($file,$errorLine,$maxLines)
{
    $errorLine--;    // adjust line number to 0-based from 1-based
    if($errorLine<0 || ($lines=@file($file))===false || ($lineCount=count($lines))<=$errorLine)
        return '';

    $halfLines=(int)($maxLines/2);
    $beginLine=$errorLine-$halfLines>0 ? $errorLine-$halfLines:0;
    $endLine=$errorLine+$halfLines<$lineCount?$errorLine+$halfLines:$lineCount-1;
    $lineNumberWidth=strlen($endLine+1);

    $output='';
    for($i=$beginLine;$i<=$endLine;++$i)
    {
        $isErrorLine = $i===$errorLine;
        $code=sprintf("<span class=\"ln".($isErrorLine?' error-ln':'')."\">%0{$lineNumberWidth}d</span> %s",$i+1,CHtml::encode(str_replace("\t",'    ',$lines[$i])));
        if(!$isErrorLine)
            $output.=$code;
        else
            $output.='<span class="error">'.$code.'</span>';
    }
    return '<div class="code"><pre>'.$output.'</pre></div>';
}