ExceptionHandler.php

<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
namespace Symfony\Component\HttpKernel\Debug;

use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpKernel\Exception\FlattenException;
if (!defined('ENT_SUBSTITUTE')) {
  define('ENT_SUBSTITUTE', 8);
}

/**
 * ExceptionHandler converts an exception to a Response object.
 *
 * It is mostly useful in debug mode to replace the default PHP/XDebug
 * output with something prettier and more useful.
 *
 * As this class is mainly used during Kernel boot, where nothing is yet
 * available, the Response content is always HTML.
 *
 * @author Fabien Potencier <fabien@symfony.com>
 */
class ExceptionHandler {
  private $debug;
  private $charset;
  public function __construct($debug = true, $charset = 'UTF-8') {
    $this->debug = $debug;
    $this->charset = $charset;
  }

  /**
   * Register the exception handler.
   *
   * @return ExceptionHandler The registered exception handler
   */
  public static function register($debug = true) {
    $handler = new static($debug);
    set_exception_handler(array(
      $handler,
      'handle',
    ));
    return $handler;
  }

  /**
   * Sends a Response for the given Exception.
   *
   * @param \Exception $exception An \Exception instance
   */
  public function handle(\Exception $exception) {
    $this
      ->createResponse($exception)
      ->send();
  }

  /**
   * Creates the error Response associated with the given Exception.
   *
   * @param \Exception|FlattenException $exception An \Exception instance
   *
   * @return Response A Response instance
   */
  public function createResponse($exception) {
    $content = '';
    $title = '';
    try {
      if (!$exception instanceof FlattenException) {
        $exception = FlattenException::create($exception);
      }
      switch ($exception
        ->getStatusCode()) {
        case 404:
          $title = 'Sorry, the page you are looking for could not be found.';
          break;
        default:
          $title = 'Whoops, looks like something went wrong.';
      }
      if ($this->debug) {
        $content = $this
          ->getContent($exception);
      }
    } catch (\Exception $e) {

      // something nasty happened and we cannot throw an exception here anymore
      if ($this->debug) {
        $title = sprintf('Exception thrown when handling an exception (%s: %s)', get_class($exception), $exception
          ->getMessage());
      }
      else {
        $title = 'Whoops, looks like something went wrong.';
      }
    }
    return new Response($this
      ->decorate($content, $title), $exception
      ->getStatusCode(), $exception
      ->getHeaders());
  }
  private function getContent($exception) {
    $message = nl2br($exception
      ->getMessage());
    $class = $this
      ->abbrClass($exception
      ->getClass());
    $count = count($exception
      ->getAllPrevious());
    $content = '';
    foreach ($exception
      ->toArray() as $position => $e) {
      $ind = $count - $position + 1;
      $total = $count + 1;
      $class = $this
        ->abbrClass($e['class']);
      $message = nl2br($e['message']);
      $content .= sprintf(<<<EOF
<div class="block_exception clear_fix">
    <h2><span>%d/%d</span> %s: %s</h2>
</div>
<div class="block">
    <ol class="traces list_exception">

EOF
, $ind, $total, $class, $message);
      foreach ($e['trace'] as $i => $trace) {
        $content .= '       <li>';
        if ($trace['function']) {
          $content .= sprintf('at %s%s%s(%s)', $this
            ->abbrClass($trace['class']), $trace['type'], $trace['function'], $this
            ->formatArgs($trace['args']));
        }
        if (isset($trace['file']) && isset($trace['line'])) {
          if ($linkFormat = ini_get('xdebug.file_link_format')) {
            $link = str_replace(array(
              '%f',
              '%l',
            ), array(
              $trace['file'],
              $trace['line'],
            ), $linkFormat);
            $content .= sprintf(' in <a href="%s" title="Go to source">%s line %s</a>', $link, $trace['file'], $trace['line']);
          }
          else {
            $content .= sprintf(' in %s line %s', $trace['file'], $trace['line']);
          }
        }
        $content .= "</li>\n";
      }
      $content .= "    </ol>\n</div>\n";
    }
    return $content;
  }
  private function decorate($content, $title) {
    return <<<EOF
<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
        <meta name="robots" content="noindex,nofollow" />
        <title>{<span class="php-variable">$title</span>}</title>
        <style>
            /* Copyright (c) 2010, Yahoo! Inc. All rights reserved. Code licensed under the BSD License: http://developer.yahoo.com/yui/license.html */
            html{color:#000;background:#FFF;}body,div,dl,dt,dd,ul,ol,li,h1,h2,h3,h4,h5,h6,pre,code,form,fieldset,legend,input,textarea,p,blockquote,th,td{margin:0;padding:0;}table{border-collapse:collapse;border-spacing:0;}fieldset,img{border:0;}address,caption,cite,code,dfn,em,strong,th,var{font-style:normal;font-weight:normal;}li{list-style:none;}caption,th{text-align:left;}h1,h2,h3,h4,h5,h6{font-size:100%;font-weight:normal;}q:before,q:after{content:'';}abbr,acronym{border:0;font-variant:normal;}sup{vertical-align:text-top;}sub{vertical-align:text-bottom;}input,textarea,select{font-family:inherit;font-size:inherit;font-weight:inherit;}input,textarea,select{*font-size:100%;}legend{color:#000;}

            html { background: #eee; padding: 10px }
            body { font: 11px Verdana, Arial, sans-serif; color: #333 }
            img { border: 0; }
            .clear { clear:both; height:0; font-size:0; line-height:0; }
            .clear_fix:after { display:block; height:0; clear:both; visibility:hidden; }
            .clear_fix { display:inline-block; }
            * html .clear_fix { height:1%; }
            .clear_fix { display:block; }
            #content { width:970px; margin:0 auto; }
            .sf-exceptionreset, .sf-exceptionreset .block { margin: auto }
            .sf-exceptionreset abbr { border-bottom: 1px dotted #000; cursor: help; }
            .sf-exceptionreset p { font-size:14px; line-height:20px; color:#868686; padding-bottom:20px }
            .sf-exceptionreset strong { font-weight:bold; }
            .sf-exceptionreset a { color:#6c6159; }
            .sf-exceptionreset a img { border:none; }
            .sf-exceptionreset a:hover { text-decoration:underline; }
            .sf-exceptionreset em { font-style:italic; }
            .sf-exceptionreset h1, .sf-exceptionreset h2 { font: 20px Georgia, "Times New Roman", Times, serif }
            .sf-exceptionreset h2 span { background-color: #fff; color: #333; padding: 6px; float: left; margin-right: 10px; }
            .sf-exceptionreset .traces li { font-size:12px; padding: 2px 4px; list-style-type:decimal; margin-left:20px; }
            .sf-exceptionreset .block { background-color:#FFFFFF; padding:10px 28px; margin-bottom:20px;
                -webkit-border-bottom-right-radius: 16px;
                -webkit-border-bottom-left-radius: 16px;
                -moz-border-radius-bottomright: 16px;
                -moz-border-radius-bottomleft: 16px;
                border-bottom-right-radius: 16px;
                border-bottom-left-radius: 16px;
                border-bottom:1px solid #ccc;
                border-right:1px solid #ccc;
                border-left:1px solid #ccc;
            }
            .sf-exceptionreset .block_exception { background-color:#ddd; color: #333; padding:20px;
                -webkit-border-top-left-radius: 16px;
                -webkit-border-top-right-radius: 16px;
                -moz-border-radius-topleft: 16px;
                -moz-border-radius-topright: 16px;
                border-top-left-radius: 16px;
                border-top-right-radius: 16px;
                border-top:1px solid #ccc;
                border-right:1px solid #ccc;
                border-left:1px solid #ccc;
            }
            .sf-exceptionreset li a { background:none; color:#868686; text-decoration:none; }
            .sf-exceptionreset li a:hover { background:none; color:#313131; text-decoration:underline; }
            .sf-exceptionreset ol { padding: 10px 0; }
            .sf-exceptionreset h1 { background-color:#FFFFFF; padding: 15px 28px; margin-bottom: 20px;
                -webkit-border-radius: 10px;
                -moz-border-radius: 10px;
                border-radius: 10px;
                border: 1px solid #ccc;
            }
        </style>
    </head>
    <body>
        <div id="content" class="sf-exceptionreset">
            <h1>{<span class="php-variable">$title</span>}</h1>
{<span class="php-variable">$content</span>}
        </div>
    </body>
</html>
EOF;
  }
  private function abbrClass($class) {
    $parts = explode('\\', $class);
    return sprintf("<abbr title=\"%s\">%s</abbr>", $class, array_pop($parts));
  }

  /**
   * Formats an array as a string.
   *
   * @param array $args The argument array
   *
   * @return string
   */
  public function formatArgs(array $args) {
    $result = array();
    foreach ($args as $key => $item) {
      if ('object' === $item[0]) {
        $formattedValue = sprintf("<em>object</em>(%s)", $this
          ->abbrClass($item[1]));
      }
      elseif ('array' === $item[0]) {
        $formattedValue = sprintf("<em>array</em>(%s)", is_array($item[1]) ? $this
          ->formatArgs($item[1]) : $item[1]);
      }
      elseif ('string' === $item[0]) {
        $formattedValue = sprintf("'%s'", htmlspecialchars($item[1], ENT_QUOTES | ENT_SUBSTITUTE, $this->charset));
      }
      elseif ('null' === $item[0]) {
        $formattedValue = '<em>null</em>';
      }
      elseif ('boolean' === $item[0]) {
        $formattedValue = '<em>' . strtolower(var_export($item[1], true)) . '</em>';
      }
      elseif ('resource' === $item[0]) {
        $formattedValue = '<em>resource</em>';
      }
      else {
        $formattedValue = str_replace("\n", '', var_export(htmlspecialchars((string) $item[1], ENT_QUOTES | ENT_SUBSTITUTE, $this->charset), true));
      }
      $result[] = is_int($key) ? $formattedValue : sprintf("'%s' => %s", $key, $formattedValue);
    }
    return implode(', ', $result);
  }

}