common.inc 133 KB
Newer Older
Dries's avatar
Dries committed
1
<?php
2
// $Id$
Dries's avatar
Dries committed
3

4 5 6 7 8 9 10 11
/**
 * @file
 * Common functions that many Drupal modules will need to reference.
 *
 * The functions that are critical and need to be available even when serving
 * a cached page are instead located in bootstrap.inc.
 */

12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
/**
 * Return status for saving which involved creating a new item.
 */
define('SAVED_NEW', 1);

/**
 * Return status for saving which involved an update to an existing item.
 */
define('SAVED_UPDATED', 2);

/**
 * Return status for saving which deleted an existing item.
 */
define('SAVED_DELETED', 3);

27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42
/**
 * The weight of JavaScript libraries, settings or jQuery plugins being
 * added to the page.
 */
define('JS_LIBRARY', -100);

/**
 * The default weight of JavaScript being added to the page.
 */
define('JS_DEFAULT', 0);

/**
 * The weight of theme JavaScript code being added to the page.
 */
define('JS_THEME', 100);

43 44 45 46 47 48 49 50
/**
 * Set content for a specified region.
 *
 * @param $region
 *   Page region the content is assigned to.
 * @param $data
 *   Content to be set.
 */
51
function drupal_set_content($region = NULL, $data = NULL) {
52 53 54 55 56 57 58 59 60 61 62 63
  static $content = array();

  if (!is_null($region) && !is_null($data)) {
    $content[$region][] = $data;
  }
  return $content;
}

/**
 * Get assigned content.
 *
 * @param $region
64 65
 *   A specified region to fetch content for. If NULL, all regions will be
 *   returned.
66 67 68
 * @param $delimiter
 *   Content to be inserted between exploded array elements.
 */
69
function drupal_get_content($region = NULL, $delimiter = ' ') {
70
  $content = drupal_set_content();
71 72
  if (isset($region)) {
    if (isset($content[$region]) && is_array($content[$region])) {
Steven Wittens's avatar
Steven Wittens committed
73
      return implode($delimiter, $content[$region]);
74
    }
75 76 77 78
  }
  else {
    foreach (array_keys($content) as $region) {
      if (is_array($content[$region])) {
Steven Wittens's avatar
Steven Wittens committed
79
        $content[$region] = implode($delimiter, $content[$region]);
80 81 82 83 84 85
      }
    }
    return $content;
  }
}

86
/**
87
 * Set the breadcrumb trail for the current page.
88
 *
89 90 91
 * @param $breadcrumb
 *   Array of links, starting with "home" and proceeding up to but not including
 *   the current page.
92
 */
93 94 95
function drupal_set_breadcrumb($breadcrumb = NULL) {
  static $stored_breadcrumb;

96
  if (!is_null($breadcrumb)) {
97 98 99 100 101
    $stored_breadcrumb = $breadcrumb;
  }
  return $stored_breadcrumb;
}

102 103 104
/**
 * Get the breadcrumb trail for the current page.
 */
105 106 107
function drupal_get_breadcrumb() {
  $breadcrumb = drupal_set_breadcrumb();

108
  if (is_null($breadcrumb)) {
109 110 111 112 113 114
    $breadcrumb = menu_get_active_breadcrumb();
  }

  return $breadcrumb;
}

115
/**
116 117
 * Return a string containing RDF namespaces for the <html> tag of an XHTML
 * page.
118 119 120 121 122 123 124 125 126 127
 */
function drupal_get_rdf_namespaces() {
  // Serialize the RDF namespaces used in RDFa annotation.
  $xml_rdf_namespaces = array();
  foreach (module_invoke_all('rdf_namespaces') as $prefix => $uri) {
    $xml_rdf_namespaces[] = 'xmlns:' . $prefix . '="' . $uri . '"';
  }
  return implode("\n  ", $xml_rdf_namespaces);
}

Dries's avatar
Dries committed
128
/**
129
 * Add output to the head tag of the HTML page.
130
 *
131
 * This function can be called as long the headers aren't sent.
Dries's avatar
Dries committed
132 133
 */
function drupal_set_html_head($data = NULL) {
134
  static $stored_head = '';
Dries's avatar
Dries committed
135 136

  if (!is_null($data)) {
137
    $stored_head .= $data . "\n";
Dries's avatar
Dries committed
138 139 140 141
  }
  return $stored_head;
}

142 143 144
/**
 * Retrieve output to be displayed in the head tag of the HTML page.
 */
Dries's avatar
Dries committed
145
function drupal_get_html_head() {
146
  $output = "<meta http-equiv=\"Content-Type\" content=\"text/html; charset=utf-8\" />\n";
Dries's avatar
Dries committed
147 148 149
  return $output . drupal_set_html_head();
}

150
/**
151
 * Reset the static variable which holds the aliases mapped for this request.
152
 */
153 154
function drupal_clear_path_cache() {
  drupal_lookup_path('wipe');
155
}
156

Dries's avatar
Dries committed
157
/**
158
 * Set an HTTP response header for the current page.
159
 *
160
 * Note: When sending a Content-Type header, always include a 'charset' type,
161
 * too. This is necessary to avoid security bugs (e.g. UTF-7 XSS).
Dries's avatar
Dries committed
162 163
 */
function drupal_set_header($header = NULL) {
164
  // We use an array to guarantee there are no leading or trailing delimiters.
165
  // Otherwise, header('') could get called when serving the page later, which
166 167
  // ends HTTP headers prematurely on some PHP versions.
  static $stored_headers = array();
Dries's avatar
Dries committed
168

169
  if (strlen($header)) {
Dries's avatar
Dries committed
170
    header($header);
171
    $stored_headers[] = $header;
Dries's avatar
Dries committed
172
  }
173
  return implode("\n", $stored_headers);
Dries's avatar
Dries committed
174 175
}

176 177 178
/**
 * Get the HTTP response headers for the current page.
 */
Dries's avatar
Dries committed
179 180 181 182
function drupal_get_headers() {
  return drupal_set_header();
}

183
/**
184 185
 * Add a feed URL for the current page.
 *
186 187
 * This function can be called as long the HTML header hasn't been sent.
 *
188
 * @param $url
189
 *   A url for the feed.
190
 * @param $title
191
 *   The title of the feed.
192
 */
193
function drupal_add_feed($url = NULL, $title = '') {
194 195
  static $stored_feed_links = array();

196
  if (!is_null($url) && !isset($stored_feed_links[$url])) {
197
    $stored_feed_links[$url] = theme('feed_icon', $url, $title);
198 199 200 201 202

    drupal_add_link(array('rel' => 'alternate',
                          'type' => 'application/rss+xml',
                          'title' => $title,
                          'href' => $url));
203 204 205 206 207 208 209 210
  }
  return $stored_feed_links;
}

/**
 * Get the feed URLs for the current page.
 *
 * @param $delimiter
211
 *   A delimiter to split feeds by.
212 213 214 215 216 217
 */
function drupal_get_feeds($delimiter = "\n") {
  $feeds = drupal_add_feed();
  return implode($feeds, $delimiter);
}

218 219 220
/**
 * @name HTTP handling
 * @{
221
 * Functions to properly handle HTTP responses.
222 223
 */

224 225 226 227
/**
 * Parse an array into a valid urlencoded query string.
 *
 * @param $query
228
 *   The array to be processed e.g. $_GET.
229
 * @param $exclude
230 231
 *   The array filled with keys to be excluded. Use parent[child] to exclude
 *   nested items.
232
 * @param $parent
233
 *   Should not be passed, only used in recursive calls.
234
 * @return
235
 *   An urlencoded string which can be appended to/as the URL query string.
236 237 238 239 240
 */
function drupal_query_string_encode($query, $exclude = array(), $parent = '') {
  $params = array();

  foreach ($query as $key => $value) {
241
    $key = drupal_urlencode($key);
242
    if ($parent) {
243
      $key = $parent . '[' . $key . ']';
244 245
    }

246
    if (in_array($key, $exclude)) {
247 248 249 250 251 252 253
      continue;
    }

    if (is_array($value)) {
      $params[] = drupal_query_string_encode($value, $exclude, $key);
    }
    else {
254
      $params[] = $key . '=' . drupal_urlencode($value);
255 256 257 258 259 260
    }
  }

  return implode('&', $params);
}

261
/**
262
 * Prepare a destination query string for use in combination with drupal_goto().
263
 *
264 265 266 267
 * Used to direct the user back to the referring page after completing a form.
 * By default the current URL is returned. If a destination exists in the
 * previous request, that destination is returned. As such, a destination can
 * persist across multiple pages.
268 269 270 271
 *
 * @see drupal_goto()
 */
function drupal_get_destination() {
272
  if (isset($_REQUEST['destination'])) {
273
    return 'destination=' . urlencode($_REQUEST['destination']);
274 275
  }
  else {
276 277
    // Use $_GET here to retrieve the original path in source form.
    $path = isset($_GET['q']) ? $_GET['q'] : '';
278 279
    $query = drupal_query_string_encode($_GET, array('q'));
    if ($query != '') {
280
      $path .= '?' . $query;
281
    }
282
    return 'destination=' . urlencode($path);
283 284 285
  }
}

286
/**
287
 * Send the user to a different Drupal page.
288
 *
289 290
 * This issues an on-site HTTP redirect. The function makes sure the redirected
 * URL is formatted correctly.
291
 *
292
 * Usually the redirected URL is constructed from this function's input
293
 * parameters. However you may override that behavior by setting a
294
 * destination in either the $_REQUEST-array (i.e. by using
295
 * the query string of an URI) This is used to direct the user back to
296
 * the proper page after completing a form. For example, after editing
297
 * a post on the 'admin/content/node'-page or after having logged on using the
298
 * 'user login'-block in a sidebar. The function drupal_get_destination()
299 300
 * can be used to help set the destination URL.
 *
301 302
 * Drupal will ensure that messages set by drupal_set_message() and other
 * session data are written to the database before the user is redirected.
303 304 305 306 307
 *
 * This function ends the request; use it rather than a print theme('page')
 * statement in your menu callback.
 *
 * @param $path
308
 *   A Drupal path or a full URL.
309
 * @param $query
310
 *   A query string component, if any.
311
 * @param $fragment
312
 *   A destination fragment identifier (named anchor).
313 314 315 316 317 318 319 320
 * @param $http_response_code
 *   Valid values for an actual "goto" as per RFC 2616 section 10.3 are:
 *   - 301 Moved Permanently (the recommended value for most redirects)
 *   - 302 Found (default in Drupal and PHP, sometimes used for spamming search
 *         engines)
 *   - 303 See Other
 *   - 304 Not Modified
 *   - 305 Use Proxy
321
 *   - 307 Temporary Redirect (alternative to "503 Site Down for Maintenance")
322
 *   Note: Other values are defined by RFC 2616, but are rarely used and poorly
323
 *   supported.
324
 * @see drupal_get_destination()
325
 */
326
function drupal_goto($path = '', $query = NULL, $fragment = NULL, $http_response_code = 302) {
327

328
  if (isset($_REQUEST['destination'])) {
329
    extract(parse_url(urldecode($_REQUEST['destination'])));
330 331
  }

332
  $url = url($path, array('query' => $query, 'fragment' => $fragment, 'absolute' => TRUE));
333 334
  // Remove newlines from the URL to avoid header injection attacks.
  $url = str_replace(array("\n", "\r"), '', $url);
335

336
  // Allow modules to react to the end of the page request before redirecting.
337
  // We do not want this while running update.php.
338
  if (!defined('MAINTENANCE_MODE') || MAINTENANCE_MODE != 'update') {
339 340
    module_invoke_all('exit', $url);
  }
341

342
  // Even though session_write_close() is registered as a shutdown function, we
343
  // need all session data written to the database before redirecting.
344
  session_write_close();
345

346
  header('Location: ' . $url, TRUE, $http_response_code);
347 348

  // The "Location" header sends a redirect status code to the HTTP daemon. In
349 350
  // some cases this can be wrong, so we make sure none of the code below the
  // drupal_goto() call gets executed upon redirection.
351 352 353
  exit();
}

354
/**
355
 * Generates a site offline message.
356 357
 */
function drupal_site_offline() {
358
  drupal_maintenance_theme();
359
  drupal_set_header($_SERVER['SERVER_PROTOCOL'] . ' 503 Service unavailable');
360
  drupal_set_title(t('Site offline'));
361
  print theme('maintenance_page', filter_xss_admin(variable_get('site_offline_message',
362
    t('@site is currently under maintenance. We should be back shortly. Thank you for your patience.', array('@site' => variable_get('site_name', 'Drupal'))))));
363 364
}

365 366 367
/**
 * Generates a 404 error if the request can not be handled.
 */
368
function drupal_not_found() {
369
  drupal_set_header($_SERVER['SERVER_PROTOCOL'] . ' 404 Not Found');
370

371
  watchdog('page not found', check_plain($_GET['q']), NULL, WATCHDOG_WARNING);
372

373
  // Keep old path for reference.
374 375 376 377
  if (!isset($_REQUEST['destination'])) {
    $_REQUEST['destination'] = $_GET['q'];
  }

378
  $path = drupal_get_normal_path(variable_get('site_404', ''));
drumm's avatar
drumm committed
379
  if ($path && $path != $_GET['q']) {
380 381 382
    // Set the active item in case there are tabs to display, or other
    // dependencies on the path.
    menu_set_active_item($path);
383
    $return = menu_execute_active_handler($path);
384
  }
385

386
  if (empty($return) || $return == MENU_NOT_FOUND || $return == MENU_ACCESS_DENIED) {
drumm's avatar
drumm committed
387
    drupal_set_title(t('Page not found'));
388
    $return = t('The requested page could not be found.');
389
  }
390

391
  // To conserve CPU and bandwidth, omit the blocks.
392
  print theme('page', $return, FALSE);
393
}
394

395 396 397 398
/**
 * Generates a 403 error if the request is not allowed.
 */
function drupal_access_denied() {
399
  drupal_set_header($_SERVER['SERVER_PROTOCOL'] . ' 403 Forbidden');
400
  watchdog('access denied', check_plain($_GET['q']), NULL, WATCHDOG_WARNING);
401

402
  // Keep old path for reference.
403 404 405 406
  if (!isset($_REQUEST['destination'])) {
    $_REQUEST['destination'] = $_GET['q'];
  }

407
  $path = drupal_get_normal_path(variable_get('site_403', ''));
drumm's avatar
drumm committed
408
  if ($path && $path != $_GET['q']) {
409
    // Set the active item in case there are tabs to display or other
410 411
    // dependencies on the path.
    menu_set_active_item($path);
412
    $return = menu_execute_active_handler($path);
413
  }
414

415
  if (empty($return) || $return == MENU_NOT_FOUND || $return == MENU_ACCESS_DENIED) {
drumm's avatar
drumm committed
416 417
    drupal_set_title(t('Access denied'));
    $return = t('You are not authorized to access this page.');
418
  }
419
  print theme('page', $return);
420 421
}

422
/**
423
 * Perform an HTTP request.
424
 *
425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440
 * This is a flexible and powerful HTTP client implementation. Correctly handles
 * GET, POST, PUT or any other HTTP requests. Handles redirects.
 *
 * @param $url
 *   A string containing a fully qualified URI.
 * @param $headers
 *   An array containing an HTTP header => value pair.
 * @param $method
 *   A string defining the HTTP request to use.
 * @param $data
 *   A string containing data to include in the request.
 * @param $retry
 *   An integer representing how many times to retry the request in case of a
 *   redirect.
 * @return
 *   An object containing the HTTP request headers, response code, headers,
441
 *   data and redirect status.
442 443
 */
function drupal_http_request($url, $headers = array(), $method = 'GET', $data = NULL, $retry = 3) {
444
  global $db_prefix;
445
  static $self_test = FALSE;
446
  $result = new stdClass();
447 448 449 450 451 452 453 454 455 456 457 458 459 460 461
  // Try to clear the drupal_http_request_fails variable if it's set. We
  // can't tie this call to any error because there is no surefire way to
  // tell whether a request has failed, so we add the check to places where
  // some parsing has failed.
  if (!$self_test && variable_get('drupal_http_request_fails', FALSE)) {
    $self_test = TRUE;
    $works = module_invoke('system', 'check_http_request');
    $self_test = FALSE;
    if (!$works) {
      // Do not bother with further operations if we already know that we
      // have no chance.
      $result->error = t("The server can't issue HTTP requests");
      return $result;
    }
  }
462

463
  // Parse the URL and make sure we can handle the schema.
464
  $uri = @parse_url($url);
465

466 467
  if ($uri == FALSE) {
    $result->error = 'unable to parse URL';
468 469 470
    return $result;
  }

471 472
  if (!isset($uri['scheme'])) {
    $result->error = 'missing schema';
473 474 475
    return $result;
  }

476 477
  switch ($uri['scheme']) {
    case 'http':
478
      $port = isset($uri['port']) ? $uri['port'] : 80;
479
      $host = $uri['host'] . ($port != 80 ? ':' . $port : '');
480
      $fp = @fsockopen($uri['host'], $port, $errno, $errstr, 15);
481 482
      break;
    case 'https':
483
      // Note: Only works when PHP is compiled with OpenSSL support.
484
      $port = isset($uri['port']) ? $uri['port'] : 443;
485 486
      $host = $uri['host'] . ($port != 443 ? ':' . $port : '');
      $fp = @fsockopen('ssl://' . $uri['host'], $port, $errno, $errstr, 20);
487 488
      break;
    default:
489
      $result->error = 'invalid schema ' . $uri['scheme'];
490 491 492
      return $result;
  }

493
  // Make sure the socket opened properly.
494
  if (!$fp) {
495 496
    // When a network error occurs, we use a negative number so it does not
    // clash with the HTTP status codes.
497 498
    $result->code = -$errno;
    $result->error = trim($errstr);
499 500 501
    return $result;
  }

502
  // Construct the path to act on.
503 504
  $path = isset($uri['path']) ? $uri['path'] : '/';
  if (isset($uri['query'])) {
505
    $path .= '?' . $uri['query'];
506 507
  }

508
  // Create HTTP request.
509
  $defaults = array(
510
    // RFC 2616: "non-standard ports MUST, default ports MAY be included".
511 512
    // We don't add the port to prevent from breaking rewrite rules checking the
    // host that do not take into account the port number.
513
    'Host' => "Host: $host",
514
    'User-Agent' => 'User-Agent: Drupal (+http://drupal.org/)',
515
    'Content-Length' => 'Content-Length: ' . strlen($data)
516 517
  );

518 519
  // If the server url has a user then attempt to use basic authentication
  if (isset($uri['user'])) {
520
    $defaults['Authorization'] = 'Authorization: Basic ' . base64_encode($uri['user'] . (!empty($uri['pass']) ? ":" . $uri['pass'] : ''));
521 522
  }

523 524 525 526 527 528
  // If the database prefix is being used by SimpleTest to run the tests in a copied
  // database then set the user-agent header to the database prefix so that any
  // calls to other Drupal pages will run the SimpleTest prefixed database. The
  // user-agent is used to ensure that multiple testing sessions running at the
  // same time won't interfere with each other as they would if the database
  // prefix were stored statically in a file or database variable.
529 530
  if (preg_match("/simpletest\d+/", $db_prefix, $matches)) {
    $headers['User-Agent'] = $matches[0];
531 532
  }

533
  foreach ($headers as $header => $value) {
534
    $defaults[$header] = $header . ': ' . trim($value);
535 536
  }

537
  $request = $method . ' ' . $path . " HTTP/1.0\r\n";
538
  $request .= implode("\r\n", $defaults);
539
  $request .= "\r\n\r\n" . $data;
540 541 542 543 544
  $result->request = $request;

  fwrite($fp, $request);

  // Fetch response.
545
  $response = '';
546 547
  while (!feof($fp) && $chunk = fread($fp, 1024)) {
    $response .= $chunk;
548 549 550 551
  }
  fclose($fp);

  // Parse response.
552 553
  list($split, $result->data) = explode("\r\n\r\n", $response, 2);
  $split = preg_split("/\r\n|\n|\r/", $split);
554

555
  list($protocol, $code, $text) = explode(' ', trim(array_shift($split)), 3);
556 557 558
  $result->headers = array();

  // Parse headers.
559
  while ($line = trim(array_shift($split))) {
560
    list($header, $value) = explode(':', $line, 2);
561 562 563
    if (isset($result->headers[$header]) && $header == 'Set-Cookie') {
      // RFC 2109: the Set-Cookie response header comprises the token Set-
      // Cookie:, followed by a comma-separated list of one or more cookies.
564
      $result->headers[$header] .= ',' . trim($value);
565 566 567 568
    }
    else {
      $result->headers[$header] = trim($value);
    }
569 570 571 572 573 574 575 576 577
  }

  $responses = array(
    100 => 'Continue', 101 => 'Switching Protocols',
    200 => 'OK', 201 => 'Created', 202 => 'Accepted', 203 => 'Non-Authoritative Information', 204 => 'No Content', 205 => 'Reset Content', 206 => 'Partial Content',
    300 => 'Multiple Choices', 301 => 'Moved Permanently', 302 => 'Found', 303 => 'See Other', 304 => 'Not Modified', 305 => 'Use Proxy', 307 => 'Temporary Redirect',
    400 => 'Bad Request', 401 => 'Unauthorized', 402 => 'Payment Required', 403 => 'Forbidden', 404 => 'Not Found', 405 => 'Method Not Allowed', 406 => 'Not Acceptable', 407 => 'Proxy Authentication Required', 408 => 'Request Time-out', 409 => 'Conflict', 410 => 'Gone', 411 => 'Length Required', 412 => 'Precondition Failed', 413 => 'Request Entity Too Large', 414 => 'Request-URI Too Large', 415 => 'Unsupported Media Type', 416 => 'Requested range not satisfiable', 417 => 'Expectation Failed',
    500 => 'Internal Server Error', 501 => 'Not Implemented', 502 => 'Bad Gateway', 503 => 'Service Unavailable', 504 => 'Gateway Time-out', 505 => 'HTTP Version not supported'
  );
578 579
  // RFC 2616 states that all unknown HTTP codes must be treated the same as the
  // base code in their class.
580 581 582 583 584 585 586 587 588 589 590 591 592 593
  if (!isset($responses[$code])) {
    $code = floor($code / 100) * 100;
  }

  switch ($code) {
    case 200: // OK
    case 304: // Not modified
      break;
    case 301: // Moved permanently
    case 302: // Moved temporarily
    case 307: // Moved temporarily
      $location = $result->headers['Location'];

      if ($retry) {
594 595
        $result = drupal_http_request($location, $headers, $method, $data, --$retry);
        $result->redirect_code = $code;
596 597 598 599 600 601 602 603 604 605 606
      }
      $result->redirect_url = $location;

      break;
    default:
      $result->error = $text;
  }

  $result->code = $code;
  return $result;
}
607 608 609
/**
 * @} End of "HTTP handling".
 */
610

611
/**
612
 * Custom PHP error handler.
613
 *
614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643
 * @param $error_level
 *   The level of the error raised.
 * @param $message
 *   The error message.
 * @param $filename
 *   The filename that the error was raised in.
 * @param $line
 *   The line number the error was raised at.
 * @param $context
 *   An array that points to the active symbol table at the point the error occurred.
 */
function _drupal_error_handler($error_level, $message, $filename, $line, $context) {
  if ($error_level & error_reporting()) {
    // All these constants are documented at http://php.net/manual/en/errorfunc.constants.php
    $types = array(
      E_ERROR => 'Error',
      E_WARNING => 'Warning',
      E_PARSE => 'Parse error',
      E_NOTICE => 'Notice',
      E_CORE_ERROR => 'Core error',
      E_CORE_WARNING => 'Core warning',
      E_COMPILE_ERROR => 'Compile error',
      E_COMPILE_WARNING => 'Compile warning',
      E_USER_ERROR => 'User error',
      E_USER_WARNING => 'User warning',
      E_USER_NOTICE => 'User notice',
      E_STRICT => 'Strict warning',
      E_RECOVERABLE_ERROR => 'Recoverable fatal error'
    );
    $backtrace = debug_backtrace();
644

645 646
    $caller = _drupal_get_last_caller(debug_backtrace());

647
    // We treat recoverable errors as fatal.
648 649 650 651 652 653 654
    _drupal_log_error(array(
      '%type' => isset($types[$error_level]) ? $types[$error_level] : 'Unknown error',
      '%message' => $message,
      '%function' => $caller['function'],
      '%file' => $caller['file'],
      '%line' => $caller['line'],
    ), $error_level == E_RECOVERABLE_ERROR);
655 656 657 658 659 660 661 662 663 664 665 666
  }
}

/**
 * Custom PHP exception handler.
 *
 * Uncaught exceptions are those not enclosed in a try/catch block. They are
 * always fatal: the execution of the script will stop as soon as the exception
 * handler exits.
 *
 * @param $exception
 *   The exception object that was thrown.
667
 */
668
function _drupal_exception_handler($exception) {
669 670 671 672 673 674 675 676 677 678 679 680
  // Log the message to the watchdog and return an error page to the user.
  _drupal_log_error(_drupal_decode_exception($exception), TRUE);
}

/**
 * Decode an exception, especially to retrive the correct caller.
 *
 * @param $exception
 *   The exception object that was thrown.
 * @return An error in the format expected by _drupal_log_error().
 */
function _drupal_decode_exception($exception) {
681 682 683 684 685 686 687 688 689 690 691
  $backtrace = $exception->getTrace();
  // Add the line throwing the exception to the backtrace.
  array_unshift($backtrace, array('line' => $exception->getLine(), 'file' => $exception->getFile()));

  // For PDOException errors, we try to return the initial caller,
  // skipping internal functions of the database layer.
  if ($exception instanceof PDOException) {
    // The first element in the stack is the call, the second element gives us the caller.
    // We skip calls that occurred in one of the classes of the database layer
    // or in one of its global functions.
    $db_functions = array('db_query', 'pager_query', 'db_query_range', 'db_query_temporary', 'update_sql');
692
    while (!empty($backtrace[1]) && ($caller = $backtrace[1]) &&
693 694 695 696 697
         ((isset($caller['class']) && (strpos($caller['class'], 'Query') !== FALSE || strpos($caller['class'], 'Database') !== FALSE)) ||
         in_array($caller['function'], $db_functions))) {
      // We remove that call.
      array_shift($backtrace);
    }
698
  }
699
  $caller = _drupal_get_last_caller($backtrace);
700

701 702 703 704 705 706 707
  return array(
    '%type' => get_class($exception),
    '%message' => $exception->getMessage(),
    '%function' => $caller['function'],
    '%file' => $caller['file'],
    '%line' => $caller['line'],
  );
708
}
709

710 711 712
/**
 * Log a PHP error or exception, display an error page in fatal cases.
 *
713 714
 * @param $error
 *   An array with the following keys: %type, %message, %function, %file, %line.
715 716 717
 * @param $fatal
 *   TRUE if the error is fatal.
 */
718
function _drupal_log_error($error, $fatal = FALSE) {
719 720 721 722
  // Initialize a maintenance theme early if the boostrap was not complete.
  // Do it early because drupal_set_message() triggers an init_theme().
  if ($fatal && (drupal_get_bootstrap_phase() != DRUPAL_BOOTSTRAP_FULL)) {
    unset($GLOBALS['theme']);
723 724 725
    if (!defined('MAINTENANCE_MODE')) {
      define('MAINTENANCE_MODE', 'error');
    }
726 727
    drupal_maintenance_theme();
  }
728

729 730
  // When running inside the testing framework, we relay the errors
  // to the tested site by the way of HTTP headers.
731
  if (preg_match("/^simpletest\d+/", $_SERVER['HTTP_USER_AGENT']) && !headers_sent() && (!defined('SIMPLETEST_COLLECT_ERRORS') || SIMPLETEST_COLLECT_ERRORS)) {
732 733
    static $number = 0;
    $assertion = array(
734 735
      $error['%message'],
      $error['%type'],
736 737 738 739 740
      array(
        'function' => $error['%function'],
        'file' => $error['%file'],
        'line' => $error['%line'],
      ),
741 742 743 744 745
    );
    header('X-Drupal-Assertion-' . $number . ': ' . rawurlencode(serialize($assertion)));
    $number++;
  }

746 747
  // Force display of error messages in update.php.
  if (variable_get('error_level', 1) == 1 || (defined('MAINTENANCE_MODE') && MAINTENANCE_MODE == 'update')) {
748
    drupal_set_message(t('%type: %message in %function (line %line of %file).', $error), 'error');
749
  }
750

751 752 753 754 755 756 757
  try {
    watchdog('php', '%type: %message in %function (line %line of %file).', $error, WATCHDOG_ERROR);
  }
  catch (Exception $e) {
    $new_error = _drupal_decode_exception($e);
    drupal_set_message(t('%type: %message in %function (line %line of %file).', $new_error), 'error');
  }
758

759 760 761
  if ($fatal) {
    drupal_set_header($_SERVER['SERVER_PROTOCOL'] . ' Service unavailable');
    drupal_set_title(t('Error'));
762
    if (!defined('MAINTENANCE_MODE') && drupal_get_bootstrap_phase() == DRUPAL_BOOTSTRAP_FULL) {
763
      print theme('page', t('The website encountered an unexpected error. Please try again later.'), FALSE);
Dries's avatar
Dries committed
764
    }
765
    else {
766
      print theme('maintenance_page', t('The website encountered an unexpected error. Please try again later.'), FALSE);
767 768
    }
    exit;
Dries's avatar
Dries committed
769 770 771
  }
}

772
/**
773
 * Gets the last caller from a backtrace.
774 775 776 777 778 779 780
 *
 * @param $backtrace
 *   A standard PHP backtrace.
 * @return
 *   An associative array with keys 'file', 'line' and 'function'.
 */
function _drupal_get_last_caller($backtrace) {
781 782 783 784 785 786
  // Errors that occur inside PHP internal functions
  // do not generate information about file and line.
  while ($backtrace && !isset($backtrace[0]['line'])) {
    array_shift($backtrace);
  }

787 788 789
  // The first trace is the call itself.
  // It gives us the line and the file of the last call.
  $call = $backtrace[0];
790

791 792 793 794 795 796 797 798 799 800 801 802 803 804 805
  // The second call give us the function where the call originated.
  if (isset($backtrace[1])) {
    if (isset($backtrace[1]['class'])) {
      $call['function'] = $backtrace[1]['class'] . $backtrace[1]['type'] . $backtrace[1]['function'] . '()';
    }
    else {
      $call['function'] = $backtrace[1]['function'] . '()';
    }
  }
  else {
    $call['function'] = 'main()';
  }
  return $call;
}

806
function _fix_gpc_magic(&$item) {
Dries's avatar
Dries committed
807
  if (is_array($item)) {
Kjartan's avatar
Kjartan committed
808 809 810
    array_walk($item, '_fix_gpc_magic');
  }
  else {
Kjartan's avatar
Kjartan committed
811
    $item = stripslashes($item);
812 813 814
  }
}

815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832
/**
 * Helper function to strip slashes from $_FILES skipping over the tmp_name keys
 * since PHP generates single backslashes for file paths on Windows systems.
 *
 * tmp_name does not have backslashes added see
 * http://php.net/manual/en/features.file-upload.php#42280
 */
function _fix_gpc_magic_files(&$item, $key) {
  if ($key != 'tmp_name') {
    if (is_array($item)) {
      array_walk($item, '_fix_gpc_magic_files');
    }
    else {
      $item = stripslashes($item);
    }
  }
}

833
/**
834
 * Fix double-escaping problems caused by "magic quotes" in some PHP installations.
835
 */
836
function fix_gpc_magic() {
837
  static $fixed = FALSE;
838
  if (!$fixed && ini_get('magic_quotes_gpc')) {
Dries's avatar
Dries committed
839 840 841 842
    array_walk($_GET, '_fix_gpc_magic');
    array_walk($_POST, '_fix_gpc_magic');
    array_walk($_COOKIE, '_fix_gpc_magic');
    array_walk($_REQUEST, '_fix_gpc_magic');
843
    array_walk($_FILES, '_fix_gpc_magic_files');
844
    $fixed = TRUE;
Dries's avatar
Dries committed
845
  }
846 847
}

848
/**
849
 * Translate strings to the page language or a given language.
850
 *
851
 * Human-readable text that will be displayed somewhere within a page should
852
 * be run through the t() function.
853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870
 *
 * Examples:
 * @code
 *   if (!$info || !$info['extension']) {
 *     form_set_error('picture_upload', t('The uploaded file was not an image.'));
 *   }
 *
 *   $form['submit'] = array(
 *     '#type' => 'submit',
 *     '#value' => t('Log in'),
 *   );
 * @endcode
 *
 * Any text within t() can be extracted by translators and changed into
 * the equivalent text in their native language.
 *
 * Special variables called "placeholders" are used to signal dynamic
 * information in a string which should not be translated. Placeholders
871 872
 * can also be used for text that may change from time to time (such as
 * link paths) to be changed without requiring updates to translations.
873 874 875 876 877 878 879 880 881 882 883 884
 *
 * For example:
 * @code
 *   $output = t('There are currently %members and %visitors online.', array(
 *     '%members' => format_plural($total_users, '1 user', '@count users'),
 *     '%visitors' => format_plural($guests->count, '1 guest', '@count guests')));
 * @endcode
 *
 * There are three styles of placeholders:
 * - !variable, which indicates that the text should be inserted as-is. This is
 *   useful for inserting variables into things like e-mail.
 *   @code
885
 *     $message[] = t("If you don't want to receive such e-mails, you can change your settings at !url.", array('!url' => url("user/$account->uid", array('absolute' => TRUE))));
886 887
 *   @endcode
 *
888 889 890
 * - @variable, which indicates that the text should be run through
 *   check_plain, to escape HTML characters. Use this for any output that's
 *   displayed within a Drupal page.
891
 *   @code
892
 *     drupal_set_title($title = t("@name's blog", array('@name' => $account->name)), PASS_THROUGH);
893 894
 *   @endcode
 *
895 896 897
 * - %variable, which indicates that the string should be HTML escaped and
 *   highlighted with theme_placeholder() which shows up by default as
 *   <em>emphasized</em>.
898
 *   @code
899
 *     $message = t('%name-from sent %name-to an e-mail.', array('%name-from' => $user->name, '%name-to' => $account->name));
900 901
 *   @endcode
 *
902
 * When using t(), try to put entire sentences and strings in one t() call.
903 904 905 906
 * This makes it easier for translators, as it provides context as to what
 * each word refers to. HTML markup within translation strings is allowed, but
 * should be avoided if possible. The exception are embedded links; link
 * titles add a context for translators, so should be kept in the main string.
907
 *
908
 * Here is an example of incorrect usage of t():
909 910 911 912 913 914
 * @code
 *   $output .= t('<p>Go to the @contact-page.</p>', array('@contact-page' => l(t('contact page'), 'contact')));
 * @endcode
 *
 * Here is an example of t() used correctly:
 * @code
915
 *   $output .= '<p>' . t('Go to the <a href="@contact-page">contact page</a>.', array('@contact-page' => url('contact'))) . '</p>';
916 917
 * @endcode
 *
918
 * Avoid escaping quotation marks wherever possible.
919 920 921 922 923 924 925
 *
 * Incorrect:
 * @code
 *   $output .= t('Don\'t click me.');
 * @endcode
 *
 * Correct:
926
 * @code
927
 *   $output .= t("Don't click me.");
928
 * @endcode
929
 *
930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970
 * Because t() is designed for handling code-based strings, in almost all
 * cases, the actual string and not a variable must be passed through t().
 *
 * Extraction of translations is done based on the strings contained in t()
 * calls. If a variable is passed through t(), the content of the variable
 * cannot be extracted from the file for translation.
 *
 * Incorrect:
 * @code
 *   $message = 'An error occurred.';
 *   drupal_set_message(t($message), 'error');
 *   $output .= t($message);
 * @endcode
 *
 * Correct:
 * @code
 *   $message = t('An error occurred.');
 *   drupal_set_message($message, 'error');
 *   $output .= $message;
 * @endcode
 *
 * The only case in which variables can be passed safely through t() is when
 * code-based versions of the same strings will be passed through t() (or
 * otherwise extracted) elsewhere.
 *
 * In some cases, modules may include strings in code that can't use t()
 * calls. For example, a module may use an external PHP application that
 * produces strings that are loaded into variables in Drupal for output.
 * In these cases, module authors may include a dummy file that passes the
 * relevant strings through t(). This approach will allow the strings to be
 * extracted.
 *
 * Sample external (non-Drupal) code:
 * @code
 *   class Time {
 *     public $yesterday = 'Yesterday';
 *     public $today = 'Today';
 *     public $tomorrow = 'Tomorrow';
 *   }
 * @endcode
 *
971
 * Sample dummy file.
972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022
 * @code
 *   // Dummy function included in example.potx.inc.
 *   function example_potx() {
 *     $strings = array(
 *       t('Yesterday'),
 *       t('Today'),
 *       t('Tomorrow'),
 *     );
 *     // No return value needed, since this is a dummy function.
 *   }
 * @endcode
 *
 * Having passed strings through t() in a dummy function, it is then
 * okay to pass variables through t().
 *
 * Correct (if a dummy file was used):
 * @code
 *   $time = new Time();
 *   $output .= t($time->today);
 * @endcode
 *
 * However tempting it is, custom data from user input or other non-code
 * sources should not be passed through t(). Doing so leads to the following
 * problems and errors:
 *  - The t() system doesn't support updates to existing strings. When user
 *    data is updated, the next time it's passed through t() a new record is
 *    created instead of an update. The database bloats over time and any
 *    existing translations are orphaned with each update.
 *  - The t() system assumes any data it receives is in English. User data may
 *    be in another language, producing translation errors.
 *  - The "Built-in interface" text group in the locale system is used to
 *    produce translations for storage in .po files. When non-code strings are
 *    passed through t(), they are added to this text group, which is rendered
 *    inaccurate since it is a mix of actual interface strings and various user
 *    input strings of uncertain origin.
 *
 * Incorrect:
 * @code
 *   $item = item_load();
 *   $output .= check_plain(t($item['title']));
 * @endcode
 *
 * Instead, translation of these data can be done through the locale system,
 * either directly or through helper functions provided by contributed
 * modules.
 * @see hook_locale()
 *
 * During installation, st() is used in place of t(). Code that may be called
 * during installation or during normal operation should use the get_t()
 * helper function.
 * @see st()
1023 1024
 * @see get_t()
 *
1025
 * @param $string
1026
 *   A string containing the English string to translate.
1027 1028
 * @param $args
 *   An associative array of replacements to make after translation. Incidences
1029 1030
 *   of any key in this array are replaced with the corresponding value. Based
 *   on the first character of the key, the value is escaped and/or themed:
1031 1032 1033 1034
 *    - !variable: inserted as is
 *    - @variable: escape plain text to HTML (check_plain)
 *    - %variable: escape text and theme as a placeholder for user-submitted
 *      content (check_plain + theme_placeholder)
1035
 * @param $langcode
1036 1037
 *   Optional language code to translate to a language other than what is used
 *   to display the page.
1038 1039
 * @return
 *   The translated string.
1040
 */
1041
function t($string, $args = array(), $langcode = NULL) {
1042
  global $language;
1043 1044
  static $custom_strings;

1045
  if (!isset($langcode)) {
1046
    $langcode = isset($language->language) ? $language->language : 'en';
1047
  }
1048

1049 1050 1051 1052
  // First, check for an array of customized strings. If present, use the array
  // *instead of* database lookups. This is a high performance way to provide a
  // handful of string replacements. See settings.php for examples.
  // Cache the $custom_strings variable to improve performance.
1053
  if (!isset($custom_strings[$langcode])) {
1054
    $custom_strings[$langcode] = variable_get('locale_custom_strings_' . $langcode, array());
1055 1056
  }
  // Custom strings work for English too, even if locale module is disabled.
1057 1058
  if (isset($custom_strings[$langcode][$string])) {
    $string = $custom_strings[$langcode][$string];
1059 1060
  }
  // Translate with locale module if enabled.
1061 1062
  elseif (function_exists('locale') && $langcode != 'en') {
    $string = locale($string, $langcode);
1063
  }
1064
  if (empty($args)) {
1065
    return $string;
Kjartan's avatar
Kjartan committed
1066 1067
  }
  else {
1068
    // Transform arguments before inserting them.
1069
    foreach ($args as $key => $value) {
1070 1071
      switch ($key[0]) {
        case '@':
1072
          // Escaped only.
1073
          $args[$key] = check_plain($value);
1074
          break;
1075

1076 1077
        case '%':
        default:
1078
          // Escaped and placeholder.
1079 1080
          $args[$key] = theme('placeholder', $value);
          break;
1081

1082
        case '!':
1083
          // Pass-through.
1084 1085
      }
    }
1086 1087
    return strtr($string, $args);
  }
1088 1089
}

1090
/**
1091
 * @defgroup validation Input validation
1092
 * @{
1093
 * Functions to validate user input.
1094 1095
 */

1096
/**
1097 1098 1099
 * Verify the syntax of the given e-mail address.
 *
 * Empty e-mail addresses are allowed. See RFC 2822 for details.
1100
 *
1101
 * @param $mail
1102
 *   A string containing an e-mail address.
1103
 * @return
1104
 *   TRUE if the address is in a valid format.
1105
 */
1106
function valid_email_address($mail) {
1107
  return (bool)filter_var($mail, FILTER_VALIDATE_EMAIL);
1108 1109
}

1110 1111 1112
/**
 * Verify the syntax of the given URL.
 *
1113 1114 1115
 * This function should only be used on actual URLs. It should not be used for
 * Drupal menu paths, which can contain arbitrary characters.
 *
1116
 * @param $url