4 * Copyright (c) 2008, David R. Nadeau, NadeauSoftware.com.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
11 * * Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
14 * * Redistributions in binary form must reproduce the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer in the documentation and/or other materials provided
17 * with the distribution.
19 * * Neither the names of David R. Nadeau or NadeauSoftware.com, nor
20 * the names of its contributors may be used to endorse or promote
21 * products derived from this software without specific prior
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
25 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
26 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
27 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
28 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
29 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
30 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
31 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
32 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
34 * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
39 * This is a BSD License approved by the Open Source Initiative (OSI).
40 * See: http://www.opensource.org/licenses/bsd-license.php
43 defined('MOODLE_INTERNAL') ||
die();
46 * Combine a base URL and a relative URL to produce a new
47 * absolute URL. The base URL is often the URL of a page,
48 * and the relative URL is a URL embedded on that page.
50 * This function implements the "absolutize" algorithm from
51 * the RFC3986 specification for URLs.
53 * This function supports multi-byte characters with the UTF-8 encoding,
54 * per the URL specification.
57 * baseUrl the absolute base URL.
59 * url the relative URL to convert.
62 * An absolute URL that combines parts of the base and relative
63 * URLs, or FALSE if the base URL is not absolute or if either
64 * URL cannot be parsed.
66 function url_to_absolute( $baseUrl, $relativeUrl )
68 // If relative URL has a scheme, clean path and return.
69 $r = split_url( $relativeUrl );
72 if ( !empty( $r['scheme'] ) )
74 if ( !empty( $r['path'] ) && $r['path'][0] == '/' )
75 $r['path'] = url_remove_dot_segments( $r['path'] );
76 return join_url( $r );
79 // Make sure the base URL is absolute.
80 $b = split_url( $baseUrl );
81 if ( $b === FALSE ||
empty( $b['scheme'] ) ||
empty( $b['host'] ) )
83 $r['scheme'] = $b['scheme'];
84 if (empty($b['path'])) {
88 // If relative URL has an authority, clean path and return.
89 if ( isset( $r['host'] ) )
91 if ( !empty( $r['path'] ) )
92 $r['path'] = url_remove_dot_segments( $r['path'] );
93 return join_url( $r );
99 // Copy base authority.
100 $r['host'] = $b['host'];
101 if ( isset( $b['port'] ) ) $r['port'] = $b['port'];
102 if ( isset( $b['user'] ) ) $r['user'] = $b['user'];
103 if ( isset( $b['pass'] ) ) $r['pass'] = $b['pass'];
105 // If relative URL has no path, use base path
106 if ( empty( $r['path'] ) )
108 if ( !empty( $b['path'] ) )
109 $r['path'] = $b['path'];
110 if ( !isset( $r['query'] ) && isset( $b['query'] ) )
111 $r['query'] = $b['query'];
112 return join_url( $r );
115 // If relative URL path doesn't start with /, merge with base path.
116 if ($r['path'][0] != '/') {
117 $base = core_text
::strrchr($b['path'], '/', TRUE);
118 if ($base === FALSE) {
121 $r['path'] = $base . '/' . $r['path'];
123 $r['path'] = url_remove_dot_segments($r['path']);
128 * Filter out "." and ".." segments from a URL's path and return
131 * This function implements the "remove_dot_segments" algorithm from
132 * the RFC3986 specification for URLs.
134 * This function supports multi-byte characters with the UTF-8 encoding,
135 * per the URL specification.
138 * path the path to filter
141 * The filtered path with "." and ".." removed.
143 function url_remove_dot_segments( $path )
145 // multi-byte character explode
146 $inSegs = preg_split( '!/!u', $path );
148 foreach ( $inSegs as $seg )
150 if ( $seg == '' ||
$seg == '.')
153 array_pop( $outSegs );
155 array_push( $outSegs, $seg );
157 $outPath = implode( '/', $outSegs );
159 if ($path[0] == '/') {
160 $outPath = '/' . $outPath;
163 // Compare last multi-byte character against '/'.
164 if ($outPath != '/' && (core_text
::strlen($path) - 1) == core_text
::strrpos($path, '/', 'UTF-8')) {
171 * This function parses an absolute or relative URL and splits it
172 * into individual components.
174 * RFC3986 specifies the components of a Uniform Resource Identifier (URI).
175 * A portion of the ABNFs are repeated here:
177 * URI-reference = URI
180 * URI = scheme ":" hier-part [ "?" query ] [ "#" fragment ]
182 * relative-ref = relative-part [ "?" query ] [ "#" fragment ]
184 * hier-part = "//" authority path-abempty
189 * relative-part = "//" authority path-abempty
194 * authority = [ userinfo "@" ] host [ ":" port ]
196 * So, a URL has the following major components:
199 * The name of a method used to interpret the rest of
200 * the URL. Examples: "http", "https", "mailto", "file'.
203 * The name of the authority governing the URL's name
204 * space. Examples: "example.com", "user@example.com",
205 * "example.com:80", "user:password@example.com:80".
207 * The authority may include a host name, port number,
208 * user name, and password.
210 * The host may be a name, an IPv4 numeric address, or
211 * an IPv6 numeric address.
214 * The hierarchical path to the URL's resource.
215 * Examples: "/index.htm", "/scripts/page.php".
218 * The data for a query. Examples: "?search=google.com".
221 * The name of a secondary resource relative to that named
222 * by the path. Examples: "#section1", "#header".
224 * An "absolute" URL must include a scheme and path. The authority, query,
225 * and fragment components are optional.
227 * A "relative" URL does not include a scheme and must include a path. The
228 * authority, query, and fragment components are optional.
230 * This function splits the $url argument into the following components
231 * and returns them in an associative array. Keys to that array include:
233 * "scheme" The scheme, such as "http".
234 * "host" The host name, IPv4, or IPv6 address.
235 * "port" The port number.
236 * "user" The user name.
237 * "pass" The user password.
238 * "path" The path, such as a file path for "http".
240 * "fragment" The fragment.
242 * One or more of these may not be present, depending upon the URL.
244 * Optionally, the "user", "pass", "host" (if a name, not an IP address),
245 * "path", "query", and "fragment" may have percent-encoded characters
246 * decoded. The "scheme" and "port" cannot include percent-encoded
247 * characters and are never decoded. Decoding occurs after the URL has
251 * url the URL to parse.
253 * decode an optional boolean flag selecting whether
254 * to decode percent encoding or not. Default = TRUE.
257 * the associative array of URL parts, or FALSE if the URL is
258 * too malformed to recognize any parts.
260 function split_url( $url, $decode=FALSE)
262 // Character sets from RFC3986.
263 $xunressub = 'a-zA-Z\d\-._~\!$&\'()*+,;=';
264 $xpchar = $xunressub . ':@% ';
266 // Scheme from RFC3986.
267 $xscheme = '([a-zA-Z][a-zA-Z\d+-.]*)';
269 // User info (user + password) from RFC3986.
270 $xuserinfo = '(([' . $xunressub . '%]*)' .
271 '(:([' . $xunressub . ':%]*))?)';
273 // IPv4 from RFC3986 (without digit constraints).
274 $xipv4 = '(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})';
276 // IPv6 from RFC2732 (without digit and grouping constraints).
277 $xipv6 = '(\[([a-fA-F\d.:]+)\])';
279 // Host name from RFC1035. Technically, must start with a letter.
280 // Relax that restriction to better parse URL structure, then
281 // leave host name validation to application.
282 $xhost_name = '([a-zA-Z\d-.%]+)';
284 // Authority from RFC3986. Skip IP future.
285 $xhost = '(' . $xhost_name . '|' . $xipv4 . '|' . $xipv6 . ')';
287 $xauthority = '((' . $xuserinfo . '@)?' . $xhost .
288 '?(:' . $xport . ')?)';
290 // Path from RFC3986. Blend absolute & relative for efficiency.
291 $xslash_seg = '(/[' . $xpchar . ']*)';
292 $xpath_authabs = '((//' . $xauthority . ')((/[' . $xpchar . ']*)*))';
293 $xpath_rel = '([' . $xpchar . ']+' . $xslash_seg . '*)';
294 $xpath_abs = '(/(' . $xpath_rel . ')?)';
295 $xapath = '(' . $xpath_authabs . '|' . $xpath_abs .
296 '|' . $xpath_rel . ')';
298 // Query and fragment from RFC3986.
299 $xqueryfrag = '([' . $xpchar . '/?' . ']*)';
302 $xurl = '^(' . $xscheme . ':)?' . $xapath . '?' .
303 '(\?' . $xqueryfrag . ')?(#' . $xqueryfrag . ')?$';
306 // Split the URL into components.
307 if ( !preg_match( '!' . $xurl . '!', $url, $m ) )
310 if ( !empty($m[2]) ) $parts['scheme'] = strtolower($m[2]);
312 if ( !empty($m[7]) ) {
313 if ( isset( $m[9] ) ) $parts['user'] = $m[9];
314 else $parts['user'] = '';
316 if ( !empty($m[10]) ) $parts['pass'] = $m[11];
318 if ( !empty($m[13]) ) $h=$parts['host'] = $m[13];
319 else if ( !empty($m[14]) ) $parts['host'] = $m[14];
320 else if ( !empty($m[16]) ) $parts['host'] = $m[16];
321 else if ( !empty( $m[5] ) ) $parts['host'] = '';
322 if ( !empty($m[17]) ) $parts['port'] = $m[18];
324 if ( !empty($m[19]) ) $parts['path'] = $m[19];
325 else if ( !empty($m[21]) ) $parts['path'] = $m[21];
326 else if ( !empty($m[25]) ) $parts['path'] = $m[25];
328 if ( !empty($m[27]) ) $parts['query'] = $m[28];
329 if ( !empty($m[29]) ) $parts['fragment']= $m[30];
333 if ( !empty($parts['user']) )
334 $parts['user'] = rawurldecode( $parts['user'] );
335 if ( !empty($parts['pass']) )
336 $parts['pass'] = rawurldecode( $parts['pass'] );
337 if ( !empty($parts['path']) )
338 $parts['path'] = rawurldecode( $parts['path'] );
340 $parts['host'] = rawurldecode( $parts['host'] );
341 if ( !empty($parts['query']) )
342 $parts['query'] = rawurldecode( $parts['query'] );
343 if ( !empty($parts['fragment']) )
344 $parts['fragment'] = rawurldecode( $parts['fragment'] );
349 * This function joins together URL components to form a complete URL.
351 * RFC3986 specifies the components of a Uniform Resource Identifier (URI).
352 * This function implements the specification's "component recomposition"
353 * algorithm for combining URI components into a full URI string.
355 * The $parts argument is an associative array containing zero or
356 * more of the following:
358 * "scheme" The scheme, such as "http".
359 * "host" The host name, IPv4, or IPv6 address.
360 * "port" The port number.
361 * "user" The user name.
362 * "pass" The user password.
363 * "path" The path, such as a file path for "http".
365 * "fragment" The fragment.
367 * The "port", "user", and "pass" values are only used when a "host"
370 * The optional $encode argument indicates if appropriate URL components
371 * should be percent-encoded as they are assembled into the URL. Encoding
372 * is only applied to the "user", "pass", "host" (if a host name, not an
373 * IP address), "path", "query", and "fragment" components. The "scheme"
374 * and "port" are never encoded. When a "scheme" and "host" are both
375 * present, the "path" is presumed to be hierarchical and encoding
376 * processes each segment of the hierarchy separately (i.e., the slashes
379 * The assembled URL string is returned.
382 * parts an associative array of strings containing the
383 * individual parts of a URL.
385 * encode an optional boolean flag selecting whether
386 * to do percent encoding or not. Default = true.
389 * Returns the assembled URL string. The string is an absolute
390 * URL if a scheme is supplied, and a relative URL if not. An
391 * empty string is returned if the $parts array does not contain
392 * any of the needed values.
394 function join_url( $parts, $encode=FALSE)
398 if ( isset( $parts['user'] ) )
399 $parts['user'] = rawurlencode( $parts['user'] );
400 if ( isset( $parts['pass'] ) )
401 $parts['pass'] = rawurlencode( $parts['pass'] );
402 if ( isset( $parts['host'] ) &&
403 !preg_match( '!^(\[[\da-f.:]+\]])|([\da-f.:]+)$!ui', $parts['host'] ) )
404 $parts['host'] = rawurlencode( $parts['host'] );
405 if ( !empty( $parts['path'] ) )
406 $parts['path'] = preg_replace( '!%2F!ui', '/',
407 rawurlencode( $parts['path'] ) );
408 if ( isset( $parts['query'] ) )
409 $parts['query'] = rawurlencode( $parts['query'] );
410 if ( isset( $parts['fragment'] ) )
411 $parts['fragment'] = rawurlencode( $parts['fragment'] );
415 if ( !empty( $parts['scheme'] ) )
416 $url .= $parts['scheme'] . ':';
417 if ( isset( $parts['host'] ) )
420 if ( isset( $parts['user'] ) )
422 $url .= $parts['user'];
423 if ( isset( $parts['pass'] ) )
424 $url .= ':' . $parts['pass'];
427 if ( preg_match( '!^[\da-f]*:[\da-f.:]+$!ui', $parts['host'] ) )
428 $url .= '[' . $parts['host'] . ']'; // IPv6
430 $url .= $parts['host']; // IPv4 or name
431 if ( isset( $parts['port'] ) )
432 $url .= ':' . $parts['port'];
433 if ( !empty( $parts['path'] ) && $parts['path'][0] != '/' )
436 if ( !empty( $parts['path'] ) )
437 $url .= $parts['path'];
438 if ( isset( $parts['query'] ) )
439 $url .= '?' . $parts['query'];
440 if ( isset( $parts['fragment'] ) )
441 $url .= '#' . $parts['fragment'];
446 * This function encodes URL to form a URL which is properly
447 * percent encoded to replace disallowed characters.
449 * RFC3986 specifies the allowed characters in the URL as well as
450 * reserved characters in the URL. This function replaces all the
451 * disallowed characters in the URL with their repective percent
452 * encodings. Already encoded characters are not encoded again,
453 * such as '%20' is not encoded to '%2520'.
456 * url the url to encode.
459 * Returns the encoded URL string.
461 function encode_url($url) {
484 $url = rawurlencode($url);
485 $url = preg_replace(array_values($reserved), array_keys($reserved), $url);
490 * Extract URLs from a web page.
492 * URLs are extracted from a long list of tags and attributes as defined
493 * by the HTML 2.0, HTML 3.2, HTML 4.01, and draft HTML 5.0 specifications.
494 * URLs are also extracted from tags and attributes that are common
495 * extensions of HTML, from the draft Forms 2.0 specification, from XHTML,
496 * and from WML 1.3 and 2.0.
498 * The function returns an associative array of associative arrays of
499 * arrays of URLs. The outermost array's keys are the tag (element) name,
500 * such as "a" for <a> or "img" for <img>. The values for these entries
501 * are associative arrays where the keys are attribute names for those
502 * tags, such as "href" for <a href="...">. Finally, the values for
503 * those arrays are URLs found in those tags and attributes throughout
507 * text the UTF-8 text to scan
510 * an associative array where keys are tags and values are an
511 * associative array where keys are attributes and values are
515 * http://nadeausoftware.com/articles/2008/01/php_tip_how_extract_urls_web_page
517 function extract_html_urls( $text )
519 $match_elements = array(
521 array('element'=>'a', 'attribute'=>'href'), // 2.0
522 array('element'=>'a', 'attribute'=>'urn'), // 2.0
523 array('element'=>'base', 'attribute'=>'href'), // 2.0
524 array('element'=>'form', 'attribute'=>'action'), // 2.0
525 array('element'=>'img', 'attribute'=>'src'), // 2.0
526 array('element'=>'link', 'attribute'=>'href'), // 2.0
528 array('element'=>'applet', 'attribute'=>'code'), // 3.2
529 array('element'=>'applet', 'attribute'=>'codebase'), // 3.2
530 array('element'=>'area', 'attribute'=>'href'), // 3.2
531 array('element'=>'body', 'attribute'=>'background'), // 3.2
532 array('element'=>'img', 'attribute'=>'usemap'), // 3.2
533 array('element'=>'input', 'attribute'=>'src'), // 3.2
535 array('element'=>'applet', 'attribute'=>'archive'), // 4.01
536 array('element'=>'applet', 'attribute'=>'object'), // 4.01
537 array('element'=>'blockquote', 'attribute'=>'cite'), // 4.01
538 array('element'=>'del', 'attribute'=>'cite'), // 4.01
539 array('element'=>'frame', 'attribute'=>'longdesc'), // 4.01
540 array('element'=>'frame', 'attribute'=>'src'), // 4.01
541 array('element'=>'head', 'attribute'=>'profile'), // 4.01
542 array('element'=>'iframe', 'attribute'=>'longdesc'), // 4.01
543 array('element'=>'iframe', 'attribute'=>'src'), // 4.01
544 array('element'=>'img', 'attribute'=>'longdesc'), // 4.01
545 array('element'=>'input', 'attribute'=>'usemap'), // 4.01
546 array('element'=>'ins', 'attribute'=>'cite'), // 4.01
547 array('element'=>'object', 'attribute'=>'archive'), // 4.01
548 array('element'=>'object', 'attribute'=>'classid'), // 4.01
549 array('element'=>'object', 'attribute'=>'codebase'), // 4.01
550 array('element'=>'object', 'attribute'=>'data'), // 4.01
551 array('element'=>'object', 'attribute'=>'usemap'), // 4.01
552 array('element'=>'q', 'attribute'=>'cite'), // 4.01
553 array('element'=>'script', 'attribute'=>'src'), // 4.01
555 array('element'=>'audio', 'attribute'=>'src'), // 5.0
556 array('element'=>'command', 'attribute'=>'icon'), // 5.0
557 array('element'=>'embed', 'attribute'=>'src'), // 5.0
558 array('element'=>'event-source','attribute'=>'src'), // 5.0
559 array('element'=>'html', 'attribute'=>'manifest'), // 5.0
560 array('element'=>'source', 'attribute'=>'src'), // 5.0
561 array('element'=>'video', 'attribute'=>'src'), // 5.0
562 array('element'=>'video', 'attribute'=>'poster'), // 5.0
564 array('element'=>'bgsound', 'attribute'=>'src'), // Extension
565 array('element'=>'body', 'attribute'=>'credits'), // Extension
566 array('element'=>'body', 'attribute'=>'instructions'), // Extension
567 array('element'=>'body', 'attribute'=>'logo'), // Extension
568 array('element'=>'div', 'attribute'=>'href'), // Extension
569 array('element'=>'div', 'attribute'=>'src'), // Extension
570 array('element'=>'embed', 'attribute'=>'code'), // Extension
571 array('element'=>'embed', 'attribute'=>'pluginspage'), // Extension
572 array('element'=>'html', 'attribute'=>'background'), // Extension
573 array('element'=>'ilayer', 'attribute'=>'src'), // Extension
574 array('element'=>'img', 'attribute'=>'dynsrc'), // Extension
575 array('element'=>'img', 'attribute'=>'lowsrc'), // Extension
576 array('element'=>'input', 'attribute'=>'dynsrc'), // Extension
577 array('element'=>'input', 'attribute'=>'lowsrc'), // Extension
578 array('element'=>'table', 'attribute'=>'background'), // Extension
579 array('element'=>'td', 'attribute'=>'background'), // Extension
580 array('element'=>'th', 'attribute'=>'background'), // Extension
581 array('element'=>'layer', 'attribute'=>'src'), // Extension
582 array('element'=>'xml', 'attribute'=>'src'), // Extension
584 array('element'=>'button', 'attribute'=>'action'), // Forms 2.0
585 array('element'=>'datalist', 'attribute'=>'data'), // Forms 2.0
586 array('element'=>'form', 'attribute'=>'data'), // Forms 2.0
587 array('element'=>'input', 'attribute'=>'action'), // Forms 2.0
588 array('element'=>'select', 'attribute'=>'data'), // Forms 2.0
591 array('element'=>'html', 'attribute'=>'xmlns'),
594 array('element'=>'access', 'attribute'=>'path'), // 1.3
595 array('element'=>'card', 'attribute'=>'onenterforward'), // 1.3
596 array('element'=>'card', 'attribute'=>'onenterbackward'),// 1.3
597 array('element'=>'card', 'attribute'=>'ontimer'), // 1.3
598 array('element'=>'go', 'attribute'=>'href'), // 1.3
599 array('element'=>'option', 'attribute'=>'onpick'), // 1.3
600 array('element'=>'template', 'attribute'=>'onenterforward'), // 1.3
601 array('element'=>'template', 'attribute'=>'onenterbackward'),// 1.3
602 array('element'=>'template', 'attribute'=>'ontimer'), // 1.3
603 array('element'=>'wml', 'attribute'=>'xmlns'), // 2.0
606 $match_metas = array(
614 // Extract all elements
615 if ( !preg_match_all( '/<([a-z][^>]*)>/iu', $text, $matches ) )
617 $elements = $matches[1];
618 $value_pattern = '=(("([^"]*)")|([^\s]*))';
620 // Match elements and attributes
621 foreach ( $match_elements as $match_element )
623 $name = $match_element['element'];
624 $attr = $match_element['attribute'];
625 $pattern = '/^' . $name . '\s.*' . $attr . $value_pattern . '/iu';
626 if ( $name == 'object' )
627 $split_pattern = '/\s*/u'; // Space-separated URL list
628 else if ( $name == 'archive' )
629 $split_pattern = '/,\s*/u'; // Comma-separated URL list
631 unset( $split_pattern ); // Single URL
632 foreach ( $elements as $element )
634 if ( !preg_match( $pattern, $element, $match ) )
636 $m = empty($match[3]) ?
(!empty($match[4])?
$match[4]:'') : $match[3];
637 if ( !isset( $split_pattern ) )
638 $urls[$name][$attr][] = $m;
641 $msplit = preg_split( $split_pattern, $m );
642 foreach ( $msplit as $ms )
643 $urls[$name][$attr][] = $ms;
648 // Match meta http-equiv elements
649 foreach ( $match_metas as $match_meta )
651 $attr_pattern = '/http-equiv="?' . $match_meta . '"?/iu';
652 $content_pattern = '/content' . $value_pattern . '/iu';
653 $refresh_pattern = '/\d*;\s*(url=)?(.*)$/iu';
654 foreach ( $elements as $element )
656 if ( !preg_match( '/^meta/iu', $element ) ||
657 !preg_match( $attr_pattern, $element ) ||
658 !preg_match( $content_pattern, $element, $match ) )
660 $m = empty($match[3]) ?
$match[4] : $match[3];
661 if ( $match_meta != 'refresh' )
662 $urls['meta']['http-equiv'][] = $m;
663 else if ( preg_match( $refresh_pattern, $m, $match ) )
664 $urls['meta']['http-equiv'][] = $match[2];
668 // Match style attributes
669 $urls['style'] = array( );
670 $style_pattern = '/style' . $value_pattern . '/iu';
671 foreach ( $elements as $element )
673 if ( !preg_match( $style_pattern, $element, $match ) )
675 $m = empty($match[3]) ?
$match[4] : $match[3];
676 $style_urls = extract_css_urls( $m );
677 if ( !empty( $style_urls ) )
678 $urls['style'] = array_merge_recursive(
679 $urls['style'], $style_urls );
682 // Match style bodies
683 if ( preg_match_all( '/<style[^>]*>(.*?)<\/style>/siu', $text, $style_bodies ) )
685 foreach ( $style_bodies[1] as $style_body )
687 $style_urls = extract_css_urls( $style_body );
688 if ( !empty( $style_urls ) )
689 $urls['style'] = array_merge_recursive(
690 $urls['style'], $style_urls );
693 if ( empty($urls['style']) )
694 unset( $urls['style'] );
699 * Extract URLs from UTF-8 CSS text.
701 * URLs within @import statements and url() property functions are extracted
702 * and returned in an associative array of arrays. Array keys indicate
703 * the use context for the URL, including:
708 * Each value in the associative array is an array of URLs.
711 * text the UTF-8 text to scan
714 * an associative array of arrays of URLs.
717 * http://nadeausoftware.com/articles/2008/01/php_tip_how_extract_urls_css_file
719 function extract_css_urls( $text )
723 $url_pattern = '(([^\\\\\'", \(\)]*(\\\\.)?)+)';
724 $urlfunc_pattern = 'url\(\s*[\'"]?' . $url_pattern . '[\'"]?\s*\)';
726 '(@import\s*[\'"]' . $url_pattern . '[\'"])' .
727 '|(@import\s*' . $urlfunc_pattern . ')' .
728 '|(' . $urlfunc_pattern . ')' . ')/iu';
729 if ( !preg_match_all( $pattern, $text, $matches ) )
734 foreach ( $matches[3] as $match )
735 if ( !empty($match) )
737 preg_replace( '/\\\\(.)/u', '\\1', $match );
740 // @import url('...')
741 // @import url("...")
742 foreach ( $matches[7] as $match )
743 if ( !empty($match) )
745 preg_replace( '/\\\\(.)/u', '\\1', $match );
750 foreach ( $matches[11] as $match )
751 if ( !empty($match) )
752 $urls['property'][] =
753 preg_replace( '/\\\\(.)/u', '\\1', $match );