common.inc 263 KB
Newer Older
Dries's avatar
 
Dries committed
1 2
<?php

3
use Drupal\Component\Utility\NestedArray;
4
use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;
5
use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
6
use Drupal\Core\Cache\CacheBackendInterface;
7
use Drupal\Core\Database\Database;
8
use Drupal\Core\Template\Attribute;
9

Dries's avatar
 
Dries committed
10 11 12 13 14 15 16 17
/**
 * @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.
 */

18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45
/**
 * @defgroup php_wrappers PHP wrapper functions
 * @{
 * Functions that are wrappers or custom implementations of PHP functions.
 *
 * Certain PHP functions should not be used in Drupal. Instead, Drupal's
 * replacement functions should be used.
 *
 * For example, for improved or more secure UTF8-handling, or RFC-compliant
 * handling of URLs in Drupal.
 *
 * For ease of use and memorizing, all these wrapper functions use the same name
 * as the original PHP function, but prefixed with "drupal_". Beware, however,
 * that not all wrapper functions support the same arguments as the original
 * functions.
 *
 * You should always use these wrapper functions in your code.
 *
 * Wrong:
 * @code
 *   $my_substring = substr($original_string, 0, 5);
 * @endcode
 *
 * Correct:
 * @code
 *   $my_substring = drupal_substr($original_string, 0, 5);
 * @endcode
 *
46
 * @}
47 48
 */

49 50 51
/**
 * Return status for saving which involved creating a new item.
 */
52
const SAVED_NEW = 1;
53 54 55 56

/**
 * Return status for saving which involved an update to an existing item.
 */
57
const SAVED_UPDATED = 2;
58 59 60 61

/**
 * Return status for saving which deleted an existing item.
 */
62
const SAVED_DELETED = 3;
63

64
/**
65
 * The default group for system CSS files added to the page.
66
 */
67
const CSS_SYSTEM = -100;
68 69

/**
70
 * The default group for module CSS files added to the page.
71
 */
72
const CSS_DEFAULT = 0;
73 74

/**
75
 * The default group for theme CSS files added to the page.
76
 */
77
const CSS_THEME = 100;
78

79
/**
80
 * The default group for JavaScript and jQuery libraries added to the page.
81
 */
82
const JS_LIBRARY = -100;
83 84

/**
85
 * The default group for module JavaScript code added to the page.
86
 */
87
const JS_DEFAULT = 0;
88 89

/**
90
 * The default group for theme JavaScript code added to the page.
91
 */
92
const JS_THEME = 100;
93

94 95 96
/**
 * The default group for JavaScript settings added to the page.
 */
97
const JS_SETTING = 200;
98

99
/**
100 101 102
 * Error code indicating that the request exceeded the specified timeout.
 *
 * @see drupal_http_request()
103
 */
104
const HTTP_REQUEST_TIMEOUT = -1;
105

106
/**
107 108 109
 * @defgroup block_caching Block Caching
 * @{
 * Constants that define each block's caching state.
110 111
 *
 * Modules specify the caching patterns for their blocks using binary
112
 * combinations of these constants in their hook_block_info().
113 114 115 116
 * DRUPAL_CACHE_PER_ROLE is used as a default when no caching pattern is
 * specified. Use DRUPAL_CACHE_CUSTOM to disable standard block cache and
 * implement
 *
117 118 119 120 121
 * The block cache is cleared when the 'content' cache tag is invalidated,
 * following the same pattern as the page cache (node, comment, user, taxonomy
 * added or updated...). Blocks requiring more fine-grained clearing might
 * consider disabling the built-in block cache (DRUPAL_NO_CACHE)
 * and roll their own.
122 123 124 125 126
 *
 * Note that user 1 is excluded from block caching.
 */

/**
127 128 129 130 131 132 133
 * The block should not get cached.
 *
 * This setting should be used:
 * - For simple blocks (notably those that do not perform any db query), where
 *   querying the db cache would be more expensive than directly generating the
 *   content.
 * - For blocks that change too frequently.
134
 */
135
const DRUPAL_NO_CACHE = -1;
136 137

/**
138 139 140 141 142
 * The block is handling its own caching in its hook_block_view().
 *
 * From the perspective of the block cache system, this is equivalent to
 * DRUPAL_NO_CACHE. Useful when time based expiration is needed or a site uses
 * a node access which invalidates standard block cache.
143
 */
144
const DRUPAL_CACHE_CUSTOM = -2;
145 146

/**
147 148 149 150
 * The block or element can change depending on the user's roles.
 *
 * This is the default setting for blocks, used when the block does not specify
 * anything.
151
 */
152
const DRUPAL_CACHE_PER_ROLE = 0x0001;
153 154

/**
155 156
 * The block or element can change depending on the user.
 *
157 158 159
 * This setting can be resource-consuming for sites with large number of users,
 * and thus should only be used when DRUPAL_CACHE_PER_ROLE is not sufficient.
 */
160
const DRUPAL_CACHE_PER_USER = 0x0002;
161 162 163 164

/**
 * The block or element can change depending on the page being viewed.
 */
165
const DRUPAL_CACHE_PER_PAGE = 0x0004;
166 167

/**
168
 * The block or element is the same for every user and page that it is visible.
169
 */
170
const DRUPAL_CACHE_GLOBAL = 0x0008;
171

172 173 174 175
/**
 * @} End of "defgroup block_caching".
 */

176 177 178 179 180 181 182 183 184
/**
 * The delimiter used to split plural strings.
 *
 * This is the ETX (End of text) character and is used as a minimal means to
 * separate singular and plural variants in source and translation text. It
 * was found to be the most compatible delimiter for the supported databases.
 */
const LOCALE_PLURAL_DELIMITER = "\03";

185
/**
186
 * Adds content to a specified region.
187 188
 *
 * @param $region
189
 *   Page region the content is added to.
190
 * @param $data
191
 *   Content to be added.
192
 */
193
function drupal_add_region_content($region = NULL, $data = NULL) {
194 195
  static $content = array();

196
  if (isset($region) && isset($data)) {
197 198 199 200 201 202
    $content[$region][] = $data;
  }
  return $content;
}

/**
203
 * Gets assigned content for a given region.
204 205
 *
 * @param $region
206 207
 *   A specified region to fetch content for. If NULL, all regions will be
 *   returned.
208
 * @param $delimiter
209
 *   Content to be inserted between imploded array elements.
210
 */
211 212
function drupal_get_region_content($region = NULL, $delimiter = ' ') {
  $content = drupal_add_region_content();
213 214
  if (isset($region)) {
    if (isset($content[$region]) && is_array($content[$region])) {
Steven Wittens's avatar
Steven Wittens committed
215
      return implode($delimiter, $content[$region]);
216
    }
217 218 219 220
  }
  else {
    foreach (array_keys($content) as $region) {
      if (is_array($content[$region])) {
Steven Wittens's avatar
Steven Wittens committed
221
        $content[$region] = implode($delimiter, $content[$region]);
222 223 224 225 226 227
      }
    }
    return $content;
  }
}

228
/**
229
 * Gets the name of the currently active install profile.
230 231 232 233
 *
 * When this function is called during Drupal's initial installation process,
 * the name of the profile that's about to be installed is stored in the global
 * installation state. At all other times, the standard Drupal systems variable
234 235
 * table contains the name of the current profile, and we can call
 * variable_get() to determine what one is active.
236 237 238 239 240 241 242 243 244 245 246
 *
 * @return $profile
 *   The name of the install profile.
 */
function drupal_get_profile() {
  global $install_state;

  if (isset($install_state['parameters']['profile'])) {
    $profile = $install_state['parameters']['profile'];
  }
  else {
247
    $profile = variable_get('install_profile', 'standard');
248 249 250 251 252 253
  }

  return $profile;
}


Dries's avatar
 
Dries committed
254
/**
255
 * Sets the breadcrumb trail for the current page.
Dries's avatar
 
Dries committed
256
 *
Dries's avatar
 
Dries committed
257 258 259
 * @param $breadcrumb
 *   Array of links, starting with "home" and proceeding up to but not including
 *   the current page.
Kjartan's avatar
Kjartan committed
260
 */
Dries's avatar
 
Dries committed
261
function drupal_set_breadcrumb($breadcrumb = NULL) {
262
  $stored_breadcrumb = &drupal_static(__FUNCTION__);
Dries's avatar
 
Dries committed
263

264
  if (isset($breadcrumb)) {
Dries's avatar
 
Dries committed
265 266 267 268 269
    $stored_breadcrumb = $breadcrumb;
  }
  return $stored_breadcrumb;
}

Dries's avatar
 
Dries committed
270
/**
271
 * Gets the breadcrumb trail for the current page.
Dries's avatar
 
Dries committed
272
 */
Dries's avatar
 
Dries committed
273 274 275
function drupal_get_breadcrumb() {
  $breadcrumb = drupal_set_breadcrumb();

276
  if (!isset($breadcrumb)) {
Dries's avatar
 
Dries committed
277 278 279 280 281 282
    $breadcrumb = menu_get_active_breadcrumb();
  }

  return $breadcrumb;
}

Dries's avatar
Dries committed
283
/**
284
 * Adds output to the HEAD tag of the HTML page.
285
 *
286
 * This function can be called as long as the headers aren't sent. Pass no
287 288 289 290 291 292 293 294 295 296 297 298 299
 * arguments (or NULL for both) to retrieve the currently stored elements.
 *
 * @param $data
 *   A renderable array. If the '#type' key is not set then 'html_tag' will be
 *   added as the default '#type'.
 * @param $key
 *   A unique string key to allow implementations of hook_html_head_alter() to
 *   identify the element in $data. Required if $data is not NULL.
 *
 * @return
 *   An array of all stored HEAD elements.
 *
 * @see theme_html_tag()
Dries's avatar
Dries committed
300
 */
301 302
function drupal_add_html_head($data = NULL, $key = NULL) {
  $stored_head = &drupal_static(__FUNCTION__);
Dries's avatar
Dries committed
303

304 305 306 307 308 309 310 311 312 313
  if (!isset($stored_head)) {
    // Make sure the defaults, including Content-Type, come first.
    $stored_head = _drupal_default_html_head();
  }

  if (isset($data) && isset($key)) {
    if (!isset($data['#type'])) {
      $data['#type'] = 'html_tag';
    }
    $stored_head[$key] = $data;
Dries's avatar
Dries committed
314 315 316 317
  }
  return $stored_head;
}

Dries's avatar
 
Dries committed
318
/**
319 320 321 322 323 324 325 326 327 328
 * Returns elements that are always displayed in the HEAD tag of the HTML page.
 */
function _drupal_default_html_head() {
  // Add default elements. Make sure the Content-Type comes first because the
  // IE browser may be vulnerable to XSS via encoding attacks from any content
  // that comes before this META tag, such as a TITLE tag.
  $elements['system_meta_content_type'] = array(
    '#type' => 'html_tag',
    '#tag' => 'meta',
    '#attributes' => array(
329
      'charset' => 'utf-8',
330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350
    ),
    // Security: This always has to be output first.
    '#weight' => -1000,
  );
  // Show Drupal and the major version number in the META GENERATOR tag.
  // Get the major version.
  list($version, ) = explode('.', VERSION);
  $elements['system_meta_generator'] = array(
    '#type' => 'html_tag',
    '#tag' => 'meta',
    '#attributes' => array(
      'name' => 'Generator',
      'content' => 'Drupal ' . $version . ' (http://drupal.org)',
    ),
  );
  // Also send the generator in the HTTP header.
  $elements['system_meta_generator']['#attached']['drupal_add_http_header'][] = array('X-Generator', $elements['system_meta_generator']['#attributes']['content']);
  return $elements;
}

/**
351
 * Retrieves output to be displayed in the HEAD tag of the HTML page.
Dries's avatar
 
Dries committed
352
 */
Dries's avatar
Dries committed
353
function drupal_get_html_head() {
354 355 356
  $elements = drupal_add_html_head();
  drupal_alter('html_head', $elements);
  return drupal_render($elements);
Dries's avatar
Dries committed
357 358
}

359
/**
360
 * Adds a feed URL for the current page.
361
 *
362 363
 * This function can be called as long the HTML header hasn't been sent.
 *
364
 * @param $url
365
 *   An internal system path or a fully qualified external URL of the feed.
366
 * @param $title
367
 *   The title of the feed.
368
 */
369
function drupal_add_feed($url = NULL, $title = '') {
370
  $stored_feed_links = &drupal_static(__FUNCTION__, array());
371

372
  if (isset($url)) {
373
    $stored_feed_links[$url] = theme('feed_icon', array('url' => $url, 'title' => $title));
374

375 376 377 378 379 380 381 382
    drupal_add_html_head_link(array(
      'rel' => 'alternate',
      'type' => 'application/rss+xml',
      'title' => $title,
      // Force the URL to be absolute, for consistency with other <link> tags
      // output by Drupal.
      'href' => url($url, array('absolute' => TRUE)),
    ));
383 384 385 386 387
  }
  return $stored_feed_links;
}

/**
388
 * Gets the feed URLs for the current page.
389 390
 *
 * @param $delimiter
391
 *   A delimiter to split feeds by.
392 393 394 395 396 397
 */
function drupal_get_feeds($delimiter = "\n") {
  $feeds = drupal_add_feed();
  return implode($feeds, $delimiter);
}

Dries's avatar
 
Dries committed
398
/**
399
 * @defgroup http_handling HTTP handling
Dries's avatar
 
Dries committed
400
 * @{
Dries's avatar
 
Dries committed
401
 * Functions to properly handle HTTP responses.
Dries's avatar
 
Dries committed
402 403
 */

404
/**
405
 * Processes a URL query parameter array to remove unwanted elements.
406 407
 *
 * @param $query
408
 *   (optional) An array to be processed. Defaults to $_GET.
409
 * @param $exclude
410
 *   (optional) A list of $query array keys to remove. Use "parent[child]" to
411
 *   exclude nested items.
412
 * @param $parent
413 414
 *   Internal use only. Used to build the $query array key for nested items.
 *
415
 * @return
416
 *   An array containing query parameters, which can be used for url().
417
 */
418
function drupal_get_query_parameters(array $query = NULL, array $exclude = array(), $parent = '') {
419 420 421 422 423 424 425 426 427 428 429
  // Set defaults, if none given.
  if (!isset($query)) {
    $query = $_GET;
  }
  // If $exclude is empty, there is nothing to filter.
  if (empty($exclude)) {
    return $query;
  }
  elseif (!$parent) {
    $exclude = array_flip($exclude);
  }
430

431
  $params = array();
432
  foreach ($query as $key => $value) {
433 434 435
    $string_key = ($parent ? $parent . '[' . $key . ']' : $key);
    if (isset($exclude[$string_key])) {
      continue;
436 437
    }

438 439 440 441 442
    if (is_array($value)) {
      $params[$key] = drupal_get_query_parameters($value, $exclude, $string_key);
    }
    else {
      $params[$key] = $value;
443
    }
444 445 446 447 448
  }

  return $params;
}

449
/**
450
 * Splits a URL-encoded query string into an array.
451 452 453 454 455
 *
 * @param $query
 *   The query string to split.
 *
 * @return
456
 *   An array of URL decoded couples $param_name => $value.
457 458 459 460 461 462
 */
function drupal_get_query_array($query) {
  $result = array();
  if (!empty($query)) {
    foreach (explode('&', $query) as $param) {
      $param = explode('=', $param);
463
      $result[$param[0]] = isset($param[1]) ? rawurldecode($param[1]) : '';
464 465 466 467 468
    }
  }
  return $result;
}

469
/**
470
 * Parses an array into a valid, rawurlencoded query string.
471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491
 *
 * This differs from http_build_query() as we need to rawurlencode() (instead of
 * urlencode()) all query parameters.
 *
 * @param $query
 *   The query parameter array to be processed, e.g. $_GET.
 * @param $parent
 *   Internal use only. Used to build the $query array key for nested items.
 *
 * @return
 *   A rawurlencoded string which can be used as or appended to the URL query
 *   string.
 *
 * @see drupal_get_query_parameters()
 * @ingroup php_wrappers
 */
function drupal_http_build_query(array $query, $parent = '') {
  $params = array();

  foreach ($query as $key => $value) {
    $key = ($parent ? $parent . '[' . rawurlencode($key) . ']' : rawurlencode($key));
492

493
    // Recurse into children.
494
    if (is_array($value)) {
495 496 497 498 499
      $params[] = drupal_http_build_query($value, $key);
    }
    // If a query parameter value is NULL, only append its key.
    elseif (!isset($value)) {
      $params[] = $key;
500 501
    }
    else {
502 503
      // For better readability of paths in query strings, we decode slashes.
      $params[] = $key . '=' . str_replace('%2F', '/', rawurlencode($value));
504 505 506 507 508 509
    }
  }

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

510
/**
511
 * Prepares a 'destination' URL query parameter for use with drupal_goto().
512
 *
513 514 515 516
 * 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.
517
 *
518 519 520 521 522 523
 * @return
 *   An associative array containing the key:
 *   - destination: The path provided via the destination query string or, if
 *     not available, the current path.
 *
 * @see current_path()
524 525 526
 * @see drupal_goto()
 */
function drupal_get_destination() {
527 528 529 530 531 532
  $destination = &drupal_static(__FUNCTION__);

  if (isset($destination)) {
    return $destination;
  }

533
  if (isset($_GET['destination'])) {
534
    $destination = array('destination' => $_GET['destination']);
535 536
  }
  else {
537
    $path = current_path();
538
    $query = drupal_http_build_query(drupal_get_query_parameters());
539
    if ($query != '') {
540
      $path .= '?' . $query;
541
    }
542 543 544 545 546 547
    $destination = array('destination' => $path);
  }
  return $destination;
}

/**
548
 * Parses a system URL string into an associative array suitable for url().
549 550
 *
 * This function should only be used for URLs that have been generated by the
551 552
 * system, such as via url(). It should not be used for URLs that come from
 * external sources, or URLs that link to external resources.
553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605
 *
 * The returned array contains a 'path' that may be passed separately to url().
 * For example:
 * @code
 *   $options = drupal_parse_url($_GET['destination']);
 *   $my_url = url($options['path'], $options);
 *   $my_link = l('Example link', $options['path'], $options);
 * @endcode
 *
 * This is required, because url() does not support relative URLs containing a
 * query string or fragment in its $path argument. Instead, any query string
 * needs to be parsed into an associative query parameter array in
 * $options['query'] and the fragment into $options['fragment'].
 *
 * @param $url
 *   The URL string to parse, f.e. $_GET['destination'].
 *
 * @return
 *   An associative array containing the keys:
 *   - 'path': The path of the URL. If the given $url is external, this includes
 *     the scheme and host.
 *   - 'query': An array of query parameters of $url, if existent.
 *   - 'fragment': The fragment of $url, if existent.
 *
 * @see url()
 * @see drupal_goto()
 * @ingroup php_wrappers
 */
function drupal_parse_url($url) {
  $options = array(
    'path' => NULL,
    'query' => array(),
    'fragment' => '',
  );

  // External URLs: not using parse_url() here, so we do not have to rebuild
  // the scheme, host, and path without having any use for it.
  if (strpos($url, '://') !== FALSE) {
    // Split off everything before the query string into 'path'.
    $parts = explode('?', $url);
    $options['path'] = $parts[0];
    // If there is a query string, transform it into keyed query parameters.
    if (isset($parts[1])) {
      $query_parts = explode('#', $parts[1]);
      parse_str($query_parts[0], $options['query']);
      // Take over the fragment, if there is any.
      if (isset($query_parts[1])) {
        $options['fragment'] = $query_parts[1];
      }
    }
  }
  // Internal URLs.
  else {
606 607 608 609 610
    // parse_url() does not support relative URLs, so make it absolute. E.g. the
    // relative URL "foo/bar:1" isn't properly parsed.
    $parts = parse_url('http://example.com/' . $url);
    // Strip the leading slash that was just added.
    $options['path'] = substr($parts['path'], 1);
611 612 613 614 615 616 617 618 619 620 621 622
    if (isset($parts['query'])) {
      parse_str($parts['query'], $options['query']);
    }
    if (isset($parts['fragment'])) {
      $options['fragment'] = $parts['fragment'];
    }
  }

  return $options;
}

/**
623
 * Encodes a Drupal path for use in a URL.
624
 *
625
 * For aesthetic reasons slashes are not escaped.
626
 *
627 628
 * Note that url() takes care of calling this function, so a path passed to that
 * function should not be encoded in advance.
629 630
 *
 * @param $path
631
 *   The Drupal path to encode.
632 633
 */
function drupal_encode_path($path) {
634
  return str_replace('%2F', '/', rawurlencode($path));
635 636
}

Kjartan's avatar
Kjartan committed
637
/**
638
 * Sends the user to a different Drupal page.
Kjartan's avatar
Kjartan committed
639
 *
Dries's avatar
 
Dries committed
640 641
 * This issues an on-site HTTP redirect. The function makes sure the redirected
 * URL is formatted correctly.
Kjartan's avatar
Kjartan committed
642
 *
643 644 645 646 647 648
 * If a destination was specified in the current request's URI (i.e.,
 * $_GET['destination']) then it will override the $path and $options values
 * passed to this function. This provides the flexibility to build a link to
 * user/login and override the default redirection so that the user is
 * redirected to a specific path after logging in:
 * @code
649 650
 *   $query = array('destination' => "node/$node->nid");
 *   $link = l(t('Log in'), 'user/login', array('query' => $query));
651
 * @endcode
652
 *
653 654
 * Drupal will ensure that messages set by drupal_set_message() and other
 * session data are written to the database before the user is redirected.
Dries's avatar
 
Dries committed
655
 *
656 657
 * This function ends the request; use it instead of a return in your menu
 * callback.
Dries's avatar
 
Dries committed
658 659
 *
 * @param $path
660 661
 *   (optional) A Drupal path or a full URL, which will be passed to url() to
 *   compute the redirect for the URL.
662
 * @param $options
663
 *   (optional) An associative array of additional URL options to pass to url().
664
 * @param $http_response_code
665 666
 *   (optional) The HTTP status code to use for the redirection, defaults to
 *   302. The valid values for 3xx redirection status codes are defined in
667 668 669 670 671 672 673 674 675 676
 *   @link http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3 RFC 2616 @endlink
 *   and the
 *   @link http://tools.ietf.org/html/draft-reschke-http-status-308-07 draft for the new HTTP status codes: @endlink
 *   - 301: Moved Permanently (the recommended value for most redirects).
 *   - 302: Found (default in Drupal and PHP, sometimes used for spamming search
 *     engines).
 *   - 303: See Other.
 *   - 304: Not Modified.
 *   - 305: Use Proxy.
 *   - 307: Temporary Redirect.
677
 *
678
 * @see drupal_get_destination()
679
 * @see url()
Kjartan's avatar
Kjartan committed
680
 */
681 682
function drupal_goto($path = '', array $options = array(), $http_response_code = 302) {
  // A destination in $_GET always overrides the function arguments.
683 684
  // We do not allow absolute URLs to be passed via $_GET, as this can be an attack vector.
  if (isset($_GET['destination']) && !url_is_external($_GET['destination'])) {
685
    $destination = drupal_parse_url($_GET['destination']);
686 687 688
    $path = $destination['path'];
    $options['query'] = $destination['query'];
    $options['fragment'] = $destination['fragment'];
689 690
  }

691 692 693 694
  drupal_alter('drupal_goto', $path, $options, $http_response_code);

  // The 'Location' HTTP header must be absolute.
  $options['absolute'] = TRUE;
695

696
  $url = url($path, $options);
Kjartan's avatar
Kjartan committed
697

698
  header('Location: ' . $url, TRUE, $http_response_code);
699 700

  // The "Location" header sends a redirect status code to the HTTP daemon. In
701 702
  // some cases this can be wrong, so we make sure none of the code below the
  // drupal_goto() call gets executed upon redirection.
703
  drupal_exit($url);
Kjartan's avatar
Kjartan committed
704 705
}

Dries's avatar
 
Dries committed
706
/**
707
 * Performs an HTTP request.
Dries's avatar
 
Dries committed
708
 *
709 710
 * This is a flexible and powerful HTTP client implementation. Correctly
 * handles GET, POST, PUT or any other HTTP requests. Handles redirects.
Dries's avatar
 
Dries committed
711 712 713
 *
 * @param $url
 *   A string containing a fully qualified URI.
714 715 716 717 718 719 720 721 722 723 724 725
 * @param array $options
 *   (optional) An array that can have one or more of the following elements:
 *   - headers: An array containing request headers to send as name/value pairs.
 *   - method: A string containing the request method. Defaults to 'GET'.
 *   - data: A string containing the request body, formatted as
 *     'param=value&param=value&...'. Defaults to NULL.
 *   - max_redirects: An integer representing how many times a redirect
 *     may be followed. Defaults to 3.
 *   - timeout: A float representing the maximum number of seconds the function
 *     call may take. The default is 30 seconds. If a timeout occurs, the error
 *     code is set to the HTTP_REQUEST_TIMEOUT constant.
 *   - context: A context resource created with stream_context_create().
726
 *
727 728 729 730 731 732 733 734 735 736
 * @return object
 *   An object that can have one or more of the following components:
 *   - request: A string containing the request body that was sent.
 *   - code: An integer containing the response status code, or the error code
 *     if an error occurred.
 *   - protocol: The response protocol (e.g. HTTP/1.1 or HTTP/1.0).
 *   - status_message: The status message from the response, if a response was
 *     received.
 *   - redirect_code: If redirected, an integer containing the initial response
 *     status code.
737 738
 *   - redirect_url: If redirected, a string containing the URL of the redirect
 *     target.
739 740 741 742 743
 *   - error: If an error occurred, the error message. Otherwise not set.
 *   - headers: An array containing the response headers as name/value pairs.
 *     HTTP header names are case-insensitive (RFC 2616, section 4.2), so for
 *     easy access the array keys are returned in lower case.
 *   - data: A string containing the response body that was received.
Dries's avatar
 
Dries committed
744
 */
745
function drupal_http_request($url, array $options = array()) {
746
  $result = new stdClass();
Dries's avatar
 
Dries committed
747

748 749 750 751
  // Parse the URL and make sure we can handle the schema.
  $uri = @parse_url($url);

  if ($uri == FALSE) {
752
    $result->error = 'unable to parse URL';
753
    $result->code = -1001;
754 755 756
    return $result;
  }

757 758 759 760 761
  if (!isset($uri['scheme'])) {
    $result->error = 'missing schema';
    $result->code = -1002;
    return $result;
  }
762

763 764 765 766 767 768 769 770
  timer_start(__FUNCTION__);

  // Merge the default options.
  $options += array(
    'headers' => array(),
    'method' => 'GET',
    'data' => NULL,
    'max_redirects' => 3,
771 772
    'timeout' => 30.0,
    'context' => NULL,
773
  );
774 775 776 777 778 779

  // Merge the default headers.
  $options['headers'] += array(
    'User-Agent' => 'Drupal (+http://drupal.org/)',
  );

780 781
  // stream_socket_client() requires timeout to be a float.
  $options['timeout'] = (float) $options['timeout'];
782

783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809
  // Use a proxy if one is defined and the host is not on the excluded list.
  $proxy_server = variable_get('proxy_server', '');
  if ($proxy_server && _drupal_http_use_proxy($uri['host'])) {
    // Set the scheme so we open a socket to the proxy server.
    $uri['scheme'] = 'proxy';
    // Set the path to be the full URL.
    $uri['path'] = $url;
    // Since the URL is passed as the path, we won't use the parsed query.
    unset($uri['query']);

    // Add in username and password to Proxy-Authorization header if needed.
    if ($proxy_username = variable_get('proxy_username', '')) {
      $proxy_password = variable_get('proxy_password', '');
      $options['headers']['Proxy-Authorization'] = 'Basic ' . base64_encode($proxy_username . (!empty($proxy_password) ? ":" . $proxy_password : ''));
    }
    // Some proxies reject requests with any User-Agent headers, while others
    // require a specific one.
    $proxy_user_agent = variable_get('proxy_user_agent', '');
    // The default value matches neither condition.
    if ($proxy_user_agent === NULL) {
      unset($options['headers']['User-Agent']);
    }
    elseif ($proxy_user_agent) {
      $options['headers']['User-Agent'] = $proxy_user_agent;
    }
  }

Dries's avatar
 
Dries committed
810
  switch ($uri['scheme']) {
811 812 813 814 815 816 817 818
    case 'proxy':
      // Make the socket connection to a proxy server.
      $socket = 'tcp://' . $proxy_server . ':' . variable_get('proxy_port', 8080);
      // The Host header still needs to match the real request.
      $options['headers']['Host'] = $uri['host'];
      $options['headers']['Host'] .= isset($uri['port']) && $uri['port'] != 80 ? ':' . $uri['port'] : '';
      break;

Dries's avatar
 
Dries committed
819
    case 'http':
820
    case 'feed':
Dries's avatar
Dries committed
821
      $port = isset($uri['port']) ? $uri['port'] : 80;
822 823 824 825 826
      $socket = 'tcp://' . $uri['host'] . ':' . $port;
      // RFC 2616: "non-standard ports MUST, default ports MAY be included".
      // We don't add the standard port to prevent from breaking rewrite rules
      // checking the host that do not take into account the port number.
      $options['headers']['Host'] = $uri['host'] . ($port != 80 ? ':' . $port : '');
Dries's avatar
 
Dries committed
827
      break;
828

Dries's avatar
 
Dries committed
829
    case 'https':
830
      // Note: Only works when PHP is compiled with OpenSSL support.
Dries's avatar
Dries committed
831
      $port = isset($uri['port']) ? $uri['port'] : 443;
832 833
      $socket = 'ssl://' . $uri['host'] . ':' . $port;
      $options['headers']['Host'] = $uri['host'] . ($port != 443 ? ':' . $port : '');
Dries's avatar
 
Dries committed
834
      break;
835

Dries's avatar
 
Dries committed
836
    default:
837
      $result->error = 'invalid schema ' . $uri['scheme'];
838
      $result->code = -1003;
Dries's avatar
 
Dries committed
839 840 841
      return $result;
  }

842 843 844 845 846 847 848 849
  if (empty($options['context'])) {
    $fp = @stream_socket_client($socket, $errno, $errstr, $options['timeout']);
  }
  else {
    // Create a stream with context. Allows verification of a SSL certificate.
    $fp = @stream_socket_client($socket, $errno, $errstr, $options['timeout'], STREAM_CLIENT_CONNECT, $options['context']);
  }

Dries's avatar
 
Dries committed
850
  // Make sure the socket opened properly.
Dries's avatar
 
Dries committed
851
  if (!$fp) {
852 853
    // When a network error occurs, we use a negative number so it does not
    // clash with the HTTP status codes.
854
    $result->code = -$errno;
855
    $result->error = trim($errstr) ? trim($errstr) : t('Error opening socket @socket', array('@socket' => $socket));
Dries's avatar
 
Dries committed
856 857 858
    return $result;
  }

Dries's avatar
 
Dries committed
859
  // Construct the path to act on.
Dries's avatar
Dries committed
860 861
  $path = isset($uri['path']) ? $uri['path'] : '/';
  if (isset($uri['query'])) {
862
    $path .= '?' . $uri['query'];
Dries's avatar
 
Dries committed
863 864
  }

865 866 867 868
  // Only add Content-Length if we actually have any content or if it is a POST
  // or PUT request. Some non-standard servers get confused by Content-Length in
  // at least HEAD/GET requests, and Squid always requires Content-Length in
  // POST/PUT requests.
869 870 871
  $content_length = strlen($options['data']);
  if ($content_length > 0 || $options['method'] == 'POST' || $options['method'] == 'PUT') {
    $options['headers']['Content-Length'] = $content_length;
872 873 874
  }

  // If the server URL has a user then attempt to use basic authentication.
875
  if (isset($uri['user'])) {
876
    $options['headers']['Authorization'] = 'Basic ' . base64_encode($uri['user'] . (isset($uri['pass']) ? ':' . $uri['pass'] : ''));
877 878
  }

879 880 881 882 883 884
  // 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.
885 886 887
  $test_info = &$GLOBALS['drupal_test_info'];
  if (!empty($test_info['test_run_id'])) {
    $options['headers']['User-Agent'] = drupal_generate_test_ua($test_info['test_run_id']);
888 889
  }

890
  $request = $options['method'] . ' ' . $path . " HTTP/1.0\r\n";
891
  foreach ($options['headers'] as $name => $value) {
892
    $request .= $name . ': ' . trim($value) . "\r\n";
Dries's avatar
 
Dries committed
893
  }
894
  $request .= "\r\n" . $options['data'];
Dries's avatar
 
Dries committed
895
  $result->request = $request;
896 897 898 899 900 901
  // Calculate how much time is left of the original timeout value.
  $timeout = $options['timeout'] - timer_read(__FUNCTION__) / 1000;
  if ($timeout > 0) {
    stream_set_timeout($fp, floor($timeout), floor(1000000 * fmod($timeout, 1)));
    fwrite($fp, $request);
  }
Dries's avatar
 
Dries committed
902

903 904 905 906 907
  // Fetch response. Due to PHP bugs like http://bugs.php.net/bug.php?id=43782
  // and http://bugs.php.net/bug.php?id=46049 we can't rely on feof(), but
  // instead must invoke stream_get_meta_data() each iteration.
  $info = stream_get_meta_data($fp);
  $alive = !$info['eof'] && !$info['timed_out'];
908
  $response = '';
909 910

  while ($alive) {
911 912 913
    // Calculate how much time is left of the original timeout value.
    $timeout = $options['timeout'] - timer_read(__FUNCTION__) / 1000;
    if ($timeout <= 0) {
914 915
      $info['timed_out'] = TRUE;
      break;
916 917
    }
    stream_set_timeout($fp, floor($timeout), floor(1000000 * fmod($timeout, 1)));
918 919 920 921
    $chunk = fread($fp, 1024);
    $response .= $chunk;
    $info = stream_get_meta_data($fp);
    $alive = !$info['eof'] && !$info['timed_out'] && $chunk;
Dries's avatar
 
Dries committed
922 923 924
  }
  fclose($fp);

925 926 927 928 929
  if ($info['timed_out']) {
    $result->code = HTTP_REQUEST_TIMEOUT;
    $result->error = 'request timed out';
    return $result;
  }
930
  // Parse response headers from the response body.
931 932 933
  // Be tolerant of malformed HTTP responses that separate header and body with
  // \n\n or \r\r instead of \r\n\r\n.
  list($response, $result->data) = preg_split("/\r\n\r\n|\n\n|\r\r/", $response, 2);
934
  $response = preg_split("/\r\n|\n|\r/", $response);
935

936
  // Parse the response status line.
937 938 939 940
  list($protocol, $code, $status_message) = explode(' ', trim(array_shift($response)), 3);
  $result->protocol = $protocol;
  $result->status_message = $status_message;

Dries's avatar
 
Dries committed
941 942
  $result->headers = array();

943 944
  // Parse the response headers.
  while ($line = trim(array_shift($response))) {
945 946 947
    list($name, $value) = explode(':', $line, 2);
    $name = strtolower($name);
    if (isset($result->headers[$name]) && $name == 'set-cookie') {
948 949
      // RFC 2109: the Set-Cookie response header comprises the token Set-
      // Cookie:, followed by a comma-separated list of one or more cookies.
950
      $result->headers[$name] .= ',' . trim($value);
951 952
    }
    else {
953
      $result->headers[$name] = trim($value);
954
    }
Dries's avatar
 
Dries committed
955 956 957
  }

  $responses = array(
958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997
    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',
Dries's avatar
 
Dries committed
998
  );
999 1000
  // RFC 2616 states that all unknown HTTP codes must be treated the same as the
  // base code in their class.
Dries's avatar
 
Dries committed
1001 1002 1003
  if (!isset($responses[$code])) {
    $code = floor($code / 100) * 100;
  }
1004
  $result->code = $code;
Dries's avatar
 
Dries committed
1005 1006 1007 1008 1009 1010 1011 1012

  switch ($code) {
    case 200: // OK
    case 304: // Not modified
      break;
    case 301: // Moved permanently
    case 302: // Moved temporarily
    case 307: // Moved temporarily
1013
      $location = $result->headers['location'];
1014 1015 1016 1017 1018 1019
      $options['timeout'] -= timer_read(__FUNCTION__) / 1000;
      if ($options['timeout'] <= 0) {
        $result->code = HTTP_REQUEST_TIMEOUT;
        $result->error = 'request timed out';
      }
      elseif ($options['max_redirects']) {
1020 1021 1022
        // Redirect to the new location.
        $options['max_redirects']--;
        $result = drupal_http_request($location, $options);
1023
        $result->redirect_code = $code;
Dries's avatar
 
Dries committed
1024
      }
1025 1026 1027
      if (!isset($result->redirect_url)) {
        $result->redirect_url = $location;
      }
Dries's avatar
 
Dries committed
1028 1029
      break;
    default:
1030
      $result->error = $status_message;
Dries's avatar
 
Dries committed
1031 1032 1033 1034
  }

  return $result;
}
1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046

/**
 * Helper function for determining hosts excluded from needing a proxy.
 *
 * @return
 *   TRUE if a proxy should be used for this host.
 */
function _drupal_http_use_proxy($host) {
  $proxy_exceptions = variable_get('proxy_exceptions', array('localhost', '127.0.0.1'));
  return !in_array(strtolower($host), $proxy_exceptions, TRUE);
}

Dries's avatar
 
Dries committed
1047
/**
1048
 * @} End of "defgroup http_handling".
Dries's avatar
 
Dries committed
1049
 */
Dries's avatar
 
Dries committed
1050

Kjartan's avatar
Kjartan committed
1051
/**
Dries's avatar
 
Dries committed
1052
 * @defgroup validation Input validation
Dries's avatar
 
Dries committed
1053
 * @{
Dries's avatar
 
Dries committed
1054
 * Functions to validate user input.
Kjartan's avatar
Kjartan committed
1055 1056
 */

1057
/**
1058
 * Verifies the syntax of the given e-mail address.
Dries's avatar
 
Dries committed
1059
 *
1060
 * See @link http://tools.ietf.org/html/rfc5321 RFC 5321 @endlink for details.
1061
 *
Dries's avatar
 
Dries committed
1062
 * @param $mail
1063
 *   A string containing an e-mail address.
1064
 *
Dries's avatar
 
Dries committed
1065
 * @return
Dries's avatar
 
Dries committed
1066
 *   TRUE if the address is in a valid format.
1067
 */
Dries's avatar
 
Dries committed
1068
function valid_email_address($mail) {
1069
  return (bool)filter_var($mail, FILTER_VALIDATE_EMAIL);
1070 1071
}

Dries's avatar
 
Dries committed
1072
/**
1073
 * Verifies the syntax of the given URL.
Dries's avatar
 
Dries committed
1074
 *
1075 1076
 * This function should only be used on actual URLs. It should not be used for
 * Drupal menu paths, which can contain arbitrary characters.
1077
 * Valid values per RFC 3986.
Dries's avatar
 
Dries committed
1078
 * @param $url
Dries's avatar
 
Dries committed
1079
 *   The URL to verify.
Dries's avatar
 
Dries committed
1080
 * @param $absolute
Dries's avatar
 
Dries committed
1081
 *   Whether the URL is absolute (beginning with a scheme such as "http:").
1082
 *
Dries's avatar
 
Dries committed
1083
 * @return
Dries's avatar
 
Dries committed
1084
 *   TRUE if the URL is in a valid format.
Dries's avatar
 
Dries committed
1085
 */
Dries's avatar
 
Dries committed
1086
function valid_url($url, $absolute = FALSE) {
1087
  if ($absolute) {
1088
    return (bool)preg_match("
1089
      /^                                                      # Start at the beginning of the text
1090
      (?:ftp|https?|feed):\/\/                                # Look for ftp, http, https or feed schemes
1091 1092 1093
      (?:                                                     # Userinfo (optional) which is typically
        (?:(?:[\w\.\-\+!$&'\(\)*\+,;=]|%[0-9a-f]{2})+:)*      # a username or a username and password
        (?:[\w\.\-\+%!$&'\(\)*\+,;=]|%[0-9a-f]{2})+@          # combination
1094
      )?
1095 1096 1097 1098 1099 1100
      (?:
        (?:[a-z0-9\-\.]|%[0-9a-f]{2})+                        # A domain name or a IPv4 address
        |(?:\[(?:[0-9a-f]{0,4}:)*(?:[0-9a-f]{0,4})\])         # or a well formed IPv6 address
      )
      (?::[0-9]+)?                                            # Server port number (optional)
      (?:[\/|\?]
1101
        (?:[\w#!:\.\?\+=&@$'~*,;\/\(\)\[\]\-]|%[0-9a-f]{2})   # The path and query (optional)
1102
      *)?
1103
    $/xi", $url);
1104 1105
  }
  else {
1106
    return (bool)preg_match("/^(?:[\w#!:\.\?\+=&@$'~*,;\/\(\)\[\]\-]|%[0-9a-f]{2})+$/i", $url);
1107
  }
Dries's avatar
 
Dries committed
1108 1109
}

1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155
/**
 * Verifies that a number is a multiple of a given step.
 *
 * The implementation assumes it is dealing with IEEE 754 double precision
 * floating point numbers that are used by PHP on most systems.
 *
 * This is based on the number/range verification methods of webkit.
 *
 * @param $value
 *   The value that needs to be checked.
 * @param $step
 *   The step scale factor. Must be positive.
 * @param $offset
 *   (optional) An offset, to which the difference must be a multiple of the
 *   given step.
 *
 * @return bool
 *   TRUE if no step mismatch has occured, or FALSE otherwise.
 *
 * @see http://opensource.apple.com/source/WebCore/WebCore-1298/html/NumberInputType.cpp
 */
function valid_number_step($value, $step, $offset = 0.0) {
  $double_value = (double) abs($value - $offset);

  // The fractional part of a double has 53 bits. The greatest number that could
  // be represented with that is 2^53. If the given value is even bigger than
  // $step * 2^53, then dividing by $step will result in a very small remainder.
  // Since that remainder can't even be represented with a single precision
  // float the following computation of the remainder makes no sense and we can
  // safely ignore it instead.
  if ($double_value / pow(2.0, 53) > $step) {
    return TRUE;
  }

  // Now compute that remainder of a division by $step.
  $remainder = (double) abs($double_value - $step * round($double_value / $step));

  // $remainder is a double precision floating point number. Remainders that
  // can't be represented with single precision floats are acceptable. The
  // fractional part of a float has 24 bits. That means remainders smaller than
  // $step * 2^-24 are acceptable.
  $computed_acceptable_error = (double)($step / pow(2.0, 24));

  return $computed_acceptable_error >= $remainder || $remainder >= ($step - $computed_acceptable_error);
}

1156 1157 1158 1159
/**
 * @} End of "defgroup validation".
 */

Dries's avatar
 
Dries committed
1160
/**
1161
 * Registers an event for the current visitor to the flood control mechanism.
Dries's avatar
 
Dries committed
1162 1163
 *
 * @param $name
1164
 *   The name of an event.
1165 1166 1167 1168 1169
 * @param $window
 *   Optional number of seconds before this event expires. Defaults to 3600 (1
 *   hour). Typically uses the same value as the flood_is_allowed() $window
 *   parameter. Expired events are purged on cron run to prevent the flood table
 *   from growing indefinitely.
1170 1171
 * @param $identifier
 *   Optional identifier (defaults to the current user's IP address).
Dries's avatar