1<?php
2
3/*
4 * This file is part of the Symfony package.
5 *
6 * (c) Fabien Potencier <fabien@symfony.com>
7 *
8 * For the full copyright and license information, please view the LICENSE
9 * file that was distributed with this source code.
10 */
11
12namespace Symfony\Component\Debug;
13
14use Symfony\Component\HttpFoundation\Response;
15use Symfony\Component\Debug\Exception\FlattenException;
16use Symfony\Component\Debug\Exception\OutOfMemoryException;
17
18/**
19 * ExceptionHandler converts an exception to a Response object.
20 *
21 * It is mostly useful in debug mode to replace the default PHP/XDebug
22 * output with something prettier and more useful.
23 *
24 * As this class is mainly used during Kernel boot, where nothing is yet
25 * available, the Response content is always HTML.
26 *
27 * @author Fabien Potencier <fabien@symfony.com>
28 * @author Nicolas Grekas <p@tchwork.com>
29 */
30class ExceptionHandler
31{
32    private $debug;
33    private $charset;
34    private $handler;
35    private $caughtBuffer;
36    private $caughtLength;
37    private $fileLinkFormat;
38
39    public function __construct($debug = true, $charset = null, $fileLinkFormat = null)
40    {
41        if (false !== strpos($charset, '%') xor false === strpos($fileLinkFormat, '%')) {
42            // Swap $charset and $fileLinkFormat for BC reasons
43            $pivot = $fileLinkFormat;
44            $fileLinkFormat = $charset;
45            $charset = $pivot;
46        }
47        $this->debug = $debug;
48        $this->charset = $charset ?: ini_get('default_charset') ?: 'UTF-8';
49        $this->fileLinkFormat = $fileLinkFormat ?: ini_get('xdebug.file_link_format') ?: get_cfg_var('xdebug.file_link_format');
50    }
51
52    /**
53     * Registers the exception handler.
54     *
55     * @param bool        $debug          Enable/disable debug mode, where the stack trace is displayed
56     * @param string|null $charset        The charset used by exception messages
57     * @param string|null $fileLinkFormat The IDE link template
58     *
59     * @return ExceptionHandler The registered exception handler
60     */
61    public static function register($debug = true, $charset = null, $fileLinkFormat = null)
62    {
63        $handler = new static($debug, $charset, $fileLinkFormat);
64
65        $prev = set_exception_handler(array($handler, 'handle'));
66        if (is_array($prev) && $prev[0] instanceof ErrorHandler) {
67            restore_exception_handler();
68            $prev[0]->setExceptionHandler(array($handler, 'handle'));
69        }
70
71        return $handler;
72    }
73
74    /**
75     * Sets a user exception handler.
76     *
77     * @param callable $handler An handler that will be called on Exception
78     *
79     * @return callable|null The previous exception handler if any
80     */
81    public function setHandler($handler)
82    {
83        if (null !== $handler && !is_callable($handler)) {
84            throw new \LogicException('The exception handler must be a valid PHP callable.');
85        }
86        $old = $this->handler;
87        $this->handler = $handler;
88
89        return $old;
90    }
91
92    /**
93     * Sets the format for links to source files.
94     *
95     * @param string $format The format for links to source files
96     *
97     * @return string The previous file link format.
98     */
99    public function setFileLinkFormat($format)
100    {
101        $old = $this->fileLinkFormat;
102        $this->fileLinkFormat = $format;
103
104        return $old;
105    }
106
107    /**
108     * Sends a response for the given Exception.
109     *
110     * To be as fail-safe as possible, the exception is first handled
111     * by our simple exception handler, then by the user exception handler.
112     * The latter takes precedence and any output from the former is cancelled,
113     * if and only if nothing bad happens in this handling path.
114     */
115    public function handle(\Exception $exception)
116    {
117        if (null === $this->handler || $exception instanceof OutOfMemoryException) {
118            $this->failSafeHandle($exception);
119
120            return;
121        }
122
123        $caughtLength = $this->caughtLength = 0;
124
125        ob_start(array($this, 'catchOutput'));
126        $this->failSafeHandle($exception);
127        while (null === $this->caughtBuffer && ob_end_flush()) {
128            // Empty loop, everything is in the condition
129        }
130        if (isset($this->caughtBuffer[0])) {
131            ob_start(array($this, 'cleanOutput'));
132            echo $this->caughtBuffer;
133            $caughtLength = ob_get_length();
134        }
135        $this->caughtBuffer = null;
136
137        try {
138            call_user_func($this->handler, $exception);
139            $this->caughtLength = $caughtLength;
140        } catch (\Exception $e) {
141            if (!$caughtLength) {
142                // All handlers failed. Let PHP handle that now.
143                throw $exception;
144            }
145        }
146    }
147
148    /**
149     * Sends a response for the given Exception.
150     *
151     * If you have the Symfony HttpFoundation component installed,
152     * this method will use it to create and send the response. If not,
153     * it will fallback to plain PHP functions.
154     *
155     * @param \Exception $exception An \Exception instance
156     *
157     * @see sendPhpResponse()
158     * @see createResponse()
159     */
160    private function failSafeHandle(\Exception $exception)
161    {
162        if (class_exists('Symfony\Component\HttpFoundation\Response', false)) {
163            $response = $this->createResponse($exception);
164            $response->sendHeaders();
165            $response->sendContent();
166        } else {
167            $this->sendPhpResponse($exception);
168        }
169    }
170
171    /**
172     * Sends the error associated with the given Exception as a plain PHP response.
173     *
174     * This method uses plain PHP functions like header() and echo to output
175     * the response.
176     *
177     * @param \Exception|FlattenException $exception An \Exception instance
178     */
179    public function sendPhpResponse($exception)
180    {
181        if (!$exception instanceof FlattenException) {
182            $exception = FlattenException::create($exception);
183        }
184
185        if (!headers_sent()) {
186            header(sprintf('HTTP/1.0 %s', $exception->getStatusCode()));
187            foreach ($exception->getHeaders() as $name => $value) {
188                header($name.': '.$value, false);
189            }
190            header('Content-Type: text/html; charset='.$this->charset);
191        }
192
193        echo $this->decorate($this->getContent($exception), $this->getStylesheet($exception));
194    }
195
196    /**
197     * Creates the error Response associated with the given Exception.
198     *
199     * @param \Exception|FlattenException $exception An \Exception instance
200     *
201     * @return Response A Response instance
202     */
203    public function createResponse($exception)
204    {
205        if (!$exception instanceof FlattenException) {
206            $exception = FlattenException::create($exception);
207        }
208
209        return Response::create($this->decorate($this->getContent($exception), $this->getStylesheet($exception)), $exception->getStatusCode(), $exception->getHeaders())->setCharset($this->charset);
210    }
211
212    /**
213     * Gets the HTML content associated with the given exception.
214     *
215     * @param FlattenException $exception A FlattenException instance
216     *
217     * @return string The content as a string
218     */
219    public function getContent(FlattenException $exception)
220    {
221        switch ($exception->getStatusCode()) {
222            case 404:
223                $title = 'Sorry, the page you are looking for could not be found.';
224                break;
225            default:
226                $title = 'Whoops, looks like something went wrong.';
227        }
228
229        $content = '';
230        if ($this->debug) {
231            try {
232                $count = count($exception->getAllPrevious());
233                $total = $count + 1;
234                foreach ($exception->toArray() as $position => $e) {
235                    $ind = $count - $position + 1;
236                    $class = $this->formatClass($e['class']);
237                    $message = nl2br($this->escapeHtml($e['message']));
238                    $content .= sprintf(<<<EOF
239                        <h2 class="block_exception clear_fix">
240                            <span class="exception_counter">%d/%d</span>
241                            <span class="exception_title">%s%s:</span>
242                            <span class="exception_message">%s</span>
243                        </h2>
244                        <div class="block">
245                            <ol class="traces list_exception">
246
247EOF
248                        , $ind, $total, $class, $this->formatPath($e['trace'][0]['file'], $e['trace'][0]['line']), $message);
249                    foreach ($e['trace'] as $trace) {
250                        $content .= '       <li>';
251                        if ($trace['function']) {
252                            $content .= sprintf('at %s%s%s(%s)', $this->formatClass($trace['class']), $trace['type'], $trace['function'], $this->formatArgs($trace['args']));
253                        }
254                        if (isset($trace['file']) && isset($trace['line'])) {
255                            $content .= $this->formatPath($trace['file'], $trace['line']);
256                        }
257                        $content .= "</li>\n";
258                    }
259
260                    $content .= "    </ol>\n</div>\n";
261                }
262            } catch (\Exception $e) {
263                // something nasty happened and we cannot throw an exception anymore
264                if ($this->debug) {
265                    $title = sprintf('Exception thrown when handling an exception (%s: %s)', get_class($e), $this->escapeHtml($e->getMessage()));
266                } else {
267                    $title = 'Whoops, looks like something went wrong.';
268                }
269            }
270        }
271
272        return <<<EOF
273            <div id="sf-resetcontent" class="sf-reset">
274                <h1>$title</h1>
275                $content
276            </div>
277EOF;
278    }
279
280    /**
281     * Gets the stylesheet associated with the given exception.
282     *
283     * @param FlattenException $exception A FlattenException instance
284     *
285     * @return string The stylesheet as a string
286     */
287    public function getStylesheet(FlattenException $exception)
288    {
289        return <<<EOF
290            .sf-reset { font: 11px Verdana, Arial, sans-serif; color: #333 }
291            .sf-reset .clear { clear:both; height:0; font-size:0; line-height:0; }
292            .sf-reset .clear_fix:after { display:block; height:0; clear:both; visibility:hidden; }
293            .sf-reset .clear_fix { display:inline-block; }
294            .sf-reset * html .clear_fix { height:1%; }
295            .sf-reset .clear_fix { display:block; }
296            .sf-reset, .sf-reset .block { margin: auto }
297            .sf-reset abbr { border-bottom: 1px dotted #000; cursor: help; }
298            .sf-reset p { font-size:14px; line-height:20px; color:#868686; padding-bottom:20px }
299            .sf-reset strong { font-weight:bold; }
300            .sf-reset a { color:#6c6159; cursor: default; }
301            .sf-reset a img { border:none; }
302            .sf-reset a:hover { text-decoration:underline; }
303            .sf-reset em { font-style:italic; }
304            .sf-reset h1, .sf-reset h2 { font: 20px Georgia, "Times New Roman", Times, serif }
305            .sf-reset .exception_counter { background-color: #fff; color: #333; padding: 6px; float: left; margin-right: 10px; float: left; display: block; }
306            .sf-reset .exception_title { margin-left: 3em; margin-bottom: 0.7em; display: block; }
307            .sf-reset .exception_message { margin-left: 3em; display: block; }
308            .sf-reset .traces li { font-size:12px; padding: 2px 4px; list-style-type:decimal; margin-left:20px; }
309            .sf-reset .block { background-color:#FFFFFF; padding:10px 28px; margin-bottom:20px;
310                -webkit-border-bottom-right-radius: 16px;
311                -webkit-border-bottom-left-radius: 16px;
312                -moz-border-radius-bottomright: 16px;
313                -moz-border-radius-bottomleft: 16px;
314                border-bottom-right-radius: 16px;
315                border-bottom-left-radius: 16px;
316                border-bottom:1px solid #ccc;
317                border-right:1px solid #ccc;
318                border-left:1px solid #ccc;
319            }
320            .sf-reset .block_exception { background-color:#ddd; color: #333; padding:20px;
321                -webkit-border-top-left-radius: 16px;
322                -webkit-border-top-right-radius: 16px;
323                -moz-border-radius-topleft: 16px;
324                -moz-border-radius-topright: 16px;
325                border-top-left-radius: 16px;
326                border-top-right-radius: 16px;
327                border-top:1px solid #ccc;
328                border-right:1px solid #ccc;
329                border-left:1px solid #ccc;
330                overflow: hidden;
331                word-wrap: break-word;
332            }
333            .sf-reset a { background:none; color:#868686; text-decoration:none; }
334            .sf-reset a:hover { background:none; color:#313131; text-decoration:underline; }
335            .sf-reset ol { padding: 10px 0; }
336            .sf-reset h1 { background-color:#FFFFFF; padding: 15px 28px; margin-bottom: 20px;
337                -webkit-border-radius: 10px;
338                -moz-border-radius: 10px;
339                border-radius: 10px;
340                border: 1px solid #ccc;
341            }
342EOF;
343    }
344
345    private function decorate($content, $css)
346    {
347        return <<<EOF
348<!DOCTYPE html>
349<html>
350    <head>
351        <meta charset="{$this->charset}" />
352        <meta name="robots" content="noindex,nofollow" />
353        <style>
354            /* Copyright (c) 2010, Yahoo! Inc. All rights reserved. Code licensed under the BSD License: http://developer.yahoo.com/yui/license.html */
355            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;}
356
357            html { background: #eee; padding: 10px }
358            img { border: 0; }
359            #sf-resetcontent { width:970px; margin:0 auto; }
360            $css
361        </style>
362    </head>
363    <body>
364        $content
365    </body>
366</html>
367EOF;
368    }
369
370    private function formatClass($class)
371    {
372        $parts = explode('\\', $class);
373
374        return sprintf('<abbr title="%s">%s</abbr>', $class, array_pop($parts));
375    }
376
377    private function formatPath($path, $line)
378    {
379        $path = $this->escapeHtml($path);
380        $file = preg_match('#[^/\\\\]*$#', $path, $file) ? $file[0] : $path;
381
382        if ($linkFormat = $this->fileLinkFormat) {
383            $link = strtr($this->escapeHtml($linkFormat), array('%f' => $path, '%l' => (int) $line));
384
385            return sprintf(' in <a href="%s" title="Go to source">%s line %d</a>', $link, $file, $line);
386        }
387
388        return sprintf(' in <a title="%s line %3$d" ondblclick="var f=this.innerHTML;this.innerHTML=this.title;this.title=f;">%s line %d</a>', $path, $file, $line);
389    }
390
391    /**
392     * Formats an array as a string.
393     *
394     * @param array $args The argument array
395     *
396     * @return string
397     */
398    private function formatArgs(array $args)
399    {
400        $result = array();
401        foreach ($args as $key => $item) {
402            if ('object' === $item[0]) {
403                $formattedValue = sprintf('<em>object</em>(%s)', $this->formatClass($item[1]));
404            } elseif ('array' === $item[0]) {
405                $formattedValue = sprintf('<em>array</em>(%s)', is_array($item[1]) ? $this->formatArgs($item[1]) : $item[1]);
406            } elseif ('string' === $item[0]) {
407                $formattedValue = sprintf("'%s'", $this->escapeHtml($item[1]));
408            } elseif ('null' === $item[0]) {
409                $formattedValue = '<em>null</em>';
410            } elseif ('boolean' === $item[0]) {
411                $formattedValue = '<em>'.strtolower(var_export($item[1], true)).'</em>';
412            } elseif ('resource' === $item[0]) {
413                $formattedValue = '<em>resource</em>';
414            } else {
415                $formattedValue = str_replace("\n", '', var_export($this->escapeHtml((string) $item[1]), true));
416            }
417
418            $result[] = is_int($key) ? $formattedValue : sprintf("'%s' => %s", $key, $formattedValue);
419        }
420
421        return implode(', ', $result);
422    }
423
424    /**
425     * Returns an UTF-8 and HTML encoded string.
426     */
427    protected static function utf8Htmlize($str)
428    {
429        if (!preg_match('//u', $str) && function_exists('iconv')) {
430            set_error_handler('var_dump', 0);
431            $charset = ini_get('default_charset');
432            if ('UTF-8' === $charset || $str !== @iconv($charset, $charset, $str)) {
433                $charset = 'CP1252';
434            }
435            restore_error_handler();
436
437            $str = iconv($charset, 'UTF-8', $str);
438        }
439
440        return htmlspecialchars($str, ENT_QUOTES | (PHP_VERSION_ID >= 50400 ? ENT_SUBSTITUTE : 0), 'UTF-8');
441    }
442
443    /**
444     * HTML-encodes a string.
445     */
446    private function escapeHtml($str)
447    {
448        return htmlspecialchars($str, ENT_QUOTES | (PHP_VERSION_ID >= 50400 ? ENT_SUBSTITUTE : 0), $this->charset);
449    }
450
451    /**
452     * @internal
453     */
454    public function catchOutput($buffer)
455    {
456        $this->caughtBuffer = $buffer;
457
458        return '';
459    }
460
461    /**
462     * @internal
463     */
464    public function cleanOutput($buffer)
465    {
466        if ($this->caughtLength) {
467            // use substr_replace() instead of substr() for mbstring overloading resistance
468            $cleanBuffer = substr_replace($buffer, '', 0, $this->caughtLength);
469            if (isset($cleanBuffer[0])) {
470                $buffer = $cleanBuffer;
471            }
472        }
473
474        return $buffer;
475    }
476}
477