MediaWiki  1.28.0
CSSMin.php
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1 <?php
30 class CSSMin {
31 
32  /* Constants */
33 
35  const PLACEHOLDER = "\x7fPLACEHOLDER\x7f";
36 
40  const DATA_URI_SIZE_LIMIT = 32768;
41  const URL_REGEX = 'url\(\s*[\'"]?(?P<file>[^\?\)\'"]*?)(?P<query>\?[^\)\'"]*?|)[\'"]?\s*\)';
42  const EMBED_REGEX = '\/\*\s*\@embed\s*\*\/';
43  const COMMENT_REGEX = '\/\*.*?\*\/';
44 
45  /* Protected Static Members */
46 
48  protected static $mimeTypes = [
49  'gif' => 'image/gif',
50  'jpe' => 'image/jpeg',
51  'jpeg' => 'image/jpeg',
52  'jpg' => 'image/jpeg',
53  'png' => 'image/png',
54  'tif' => 'image/tiff',
55  'tiff' => 'image/tiff',
56  'xbm' => 'image/x-xbitmap',
57  'svg' => 'image/svg+xml',
58  ];
59 
60  /* Static Methods */
61 
69  public static function getLocalFileReferences( $source, $path ) {
70  $stripped = preg_replace( '/' . self::COMMENT_REGEX . '/s', '', $source );
71  $path = rtrim( $path, '/' ) . '/';
72  $files = [];
73 
74  $rFlags = PREG_OFFSET_CAPTURE | PREG_SET_ORDER;
75  if ( preg_match_all( '/' . self::URL_REGEX . '/', $stripped, $matches, $rFlags ) ) {
76  foreach ( $matches as $match ) {
77  $url = $match['file'][0];
78 
79  // Skip fully-qualified and protocol-relative URLs and data URIs
80  if ( substr( $url, 0, 2 ) === '//' || parse_url( $url, PHP_URL_SCHEME ) ) {
81  break;
82  }
83 
84  $files[] = $path . $url;
85  }
86  }
87  return $files;
88  }
89 
105  public static function encodeImageAsDataURI( $file, $type = null, $ie8Compat = true ) {
106  // Fast-fail for files that definitely exceed the maximum data URI length
107  if ( $ie8Compat && filesize( $file ) >= self::DATA_URI_SIZE_LIMIT ) {
108  return false;
109  }
110 
111  if ( $type === null ) {
112  $type = self::getMimeType( $file );
113  }
114  if ( !$type ) {
115  return false;
116  }
117 
118  return self::encodeStringAsDataURI( file_get_contents( $file ), $type, $ie8Compat );
119  }
120 
133  public static function encodeStringAsDataURI( $contents, $type, $ie8Compat = true ) {
134  // Try #1: Non-encoded data URI
135  // The regular expression matches ASCII whitespace and printable characters.
136  if ( preg_match( '/^[\r\n\t\x20-\x7e]+$/', $contents ) ) {
137  // Do not base64-encode non-binary files (sane SVGs).
138  // (This often produces longer URLs, but they compress better, yielding a net smaller size.)
139  $uri = 'data:' . $type . ',' . rawurlencode( $contents );
140  if ( !$ie8Compat || strlen( $uri ) < self::DATA_URI_SIZE_LIMIT ) {
141  return $uri;
142  }
143  }
144 
145  // Try #2: Encoded data URI
146  $uri = 'data:' . $type . ';base64,' . base64_encode( $contents );
147  if ( !$ie8Compat || strlen( $uri ) < self::DATA_URI_SIZE_LIMIT ) {
148  return $uri;
149  }
150 
151  // A data URI couldn't be produced
152  return false;
153  }
154 
163  public static function serializeStringValue( $value ) {
164  if ( strstr( $value, "\0" ) ) {
165  throw new Exception( "Invalid character in CSS string" );
166  }
167  $value = strtr( $value, [ '\\' => '\\\\', '"' => '\\"' ] );
168  $value = preg_replace_callback( '/[\x01-\x1f\x7f-\x9f]/', function ( $match ) {
169  return '\\' . base_convert( ord( $match[0] ), 10, 16 ) . ' ';
170  }, $value );
171  return '"' . $value . '"';
172  }
173 
178  public static function getMimeType( $file ) {
179  $realpath = realpath( $file );
180  if (
181  $realpath
182  && function_exists( 'finfo_file' )
183  && function_exists( 'finfo_open' )
184  && defined( 'FILEINFO_MIME_TYPE' )
185  ) {
186  return finfo_file( finfo_open( FILEINFO_MIME_TYPE ), $realpath );
187  }
188 
189  // Infer the MIME-type from the file extension
190  $ext = strtolower( pathinfo( $file, PATHINFO_EXTENSION ) );
191  if ( isset( self::$mimeTypes[$ext] ) ) {
192  return self::$mimeTypes[$ext];
193  }
194 
195  return false;
196  }
197 
207  public static function buildUrlValue( $url ) {
208  // The list below has been crafted to match URLs such as:
209  // scheme://user@domain:port/~user/fi%20le.png?query=yes&really=y+s
210  // data:image/png;base64,R0lGODlh/+==
211  if ( preg_match( '!^[\w\d:@/~.%+;,?&=-]+$!', $url ) ) {
212  return "url($url)";
213  } else {
214  return 'url("' . strtr( $url, [ '\\' => '\\\\', '"' => '\\"' ] ) . '")';
215  }
216  }
217 
229  public static function remap( $source, $local, $remote, $embedData = true ) {
230  // High-level overview:
231  // * For each CSS rule in $source that includes at least one url() value:
232  // * Check for an @embed comment at the start indicating that all URIs should be embedded
233  // * For each url() value:
234  // * Check for an @embed comment directly preceding the value
235  // * If either @embed comment exists:
236  // * Embedding the URL as data: URI, if it's possible / allowed
237  // * Otherwise remap the URL to work in generated stylesheets
238 
239  // Guard against trailing slashes, because "some/remote/../foo.png"
240  // resolves to "some/remote/foo.png" on (some?) clients (bug 27052).
241  if ( substr( $remote, -1 ) == '/' ) {
242  $remote = substr( $remote, 0, -1 );
243  }
244 
245  // Disallow U+007F DELETE, which is illegal anyway, and which
246  // we use for comment placeholders.
247  $source = str_replace( "\x7f", "?", $source );
248 
249  // Replace all comments by a placeholder so they will not interfere with the remapping.
250  // Warning: This will also catch on anything looking like the start of a comment between
251  // quotation marks (e.g. "foo /* bar").
252  $comments = [];
253 
254  $pattern = '/(?!' . CSSMin::EMBED_REGEX . ')(' . CSSMin::COMMENT_REGEX . ')/s';
255 
256  $source = preg_replace_callback(
257  $pattern,
258  function ( $match ) use ( &$comments ) {
259  $comments[] = $match[ 0 ];
260  return CSSMin::PLACEHOLDER . ( count( $comments ) - 1 ) . 'x';
261  },
262  $source
263  );
264 
265  // Note: This will not correctly handle cases where ';', '{' or '}'
266  // appears in the rule itself, e.g. in a quoted string. You are advised
267  // not to use such characters in file names. We also match start/end of
268  // the string to be consistent in edge-cases ('@import url(…)').
269  $pattern = '/(?:^|[;{])\K[^;{}]*' . CSSMin::URL_REGEX . '[^;}]*(?=[;}]|$)/';
270 
271  $source = preg_replace_callback(
272  $pattern,
273  function ( $matchOuter ) use ( $local, $remote, $embedData ) {
274  $rule = $matchOuter[0];
275 
276  // Check for global @embed comment and remove it. Allow other comments to be present
277  // before @embed (they have been replaced with placeholders at this point).
278  $embedAll = false;
279  $rule = preg_replace(
280  '/^((?:\s+|' .
281  CSSMin::PLACEHOLDER .
282  '(\d+)x)*)' .
284  '\s*/',
285  '$1',
286  $rule,
287  1,
288  $embedAll
289  );
290 
291  // Build two versions of current rule: with remapped URLs
292  // and with embedded data: URIs (where possible).
293  $pattern = '/(?P<embed>' . CSSMin::EMBED_REGEX . '\s*|)' . CSSMin::URL_REGEX . '/';
294 
295  $ruleWithRemapped = preg_replace_callback(
296  $pattern,
297  function ( $match ) use ( $local, $remote ) {
298  $remapped = CSSMin::remapOne( $match['file'], $match['query'], $local, $remote, false );
299 
300  return CSSMin::buildUrlValue( $remapped );
301  },
302  $rule
303  );
304 
305  if ( $embedData ) {
306  // Remember the occurring MIME types to avoid fallbacks when embedding some files.
307  $mimeTypes = [];
308 
309  $ruleWithEmbedded = preg_replace_callback(
310  $pattern,
311  function ( $match ) use ( $embedAll, $local, $remote, &$mimeTypes ) {
312  $embed = $embedAll || $match['embed'];
313  $embedded = CSSMin::remapOne(
314  $match['file'],
315  $match['query'],
316  $local,
317  $remote,
318  $embed
319  );
320 
321  $url = $match['file'] . $match['query'];
322  $file = $local . $match['file'];
323  if (
324  !self::isRemoteUrl( $url ) && !self::isLocalUrl( $url )
325  && file_exists( $file )
326  ) {
327  $mimeTypes[ CSSMin::getMimeType( $file ) ] = true;
328  }
329 
330  return CSSMin::buildUrlValue( $embedded );
331  },
332  $rule
333  );
334 
335  // Are all referenced images SVGs?
336  $needsEmbedFallback = $mimeTypes !== [ 'image/svg+xml' => true ];
337  }
338 
339  if ( !$embedData || $ruleWithEmbedded === $ruleWithRemapped ) {
340  // We're not embedding anything, or we tried to but the file is not embeddable
341  return $ruleWithRemapped;
342  } elseif ( $embedData && $needsEmbedFallback ) {
343  // Build 2 CSS properties; one which uses a data URI in place of the @embed comment, and
344  // the other with a remapped and versioned URL with an Internet Explorer 6 and 7 hack
345  // making it ignored in all browsers that support data URIs
346  return "$ruleWithEmbedded;$ruleWithRemapped!ie";
347  } else {
348  // Look ma, no fallbacks! This is for files which IE 6 and 7 don't support anyway: SVG.
349  return $ruleWithEmbedded;
350  }
351  }, $source );
352 
353  // Re-insert comments
354  $pattern = '/' . CSSMin::PLACEHOLDER . '(\d+)x/';
355  $source = preg_replace_callback( $pattern, function( $match ) use ( &$comments ) {
356  return $comments[ $match[1] ];
357  }, $source );
358 
359  return $source;
360 
361  }
362 
369  protected static function isRemoteUrl( $maybeUrl ) {
370  if ( substr( $maybeUrl, 0, 2 ) === '//' || parse_url( $maybeUrl, PHP_URL_SCHEME ) ) {
371  return true;
372  }
373  return false;
374  }
375 
382  protected static function isLocalUrl( $maybeUrl ) {
383  if ( $maybeUrl !== '' && $maybeUrl[0] === '/' && !self::isRemoteUrl( $maybeUrl ) ) {
384  return true;
385  }
386  return false;
387  }
388 
399  public static function remapOne( $file, $query, $local, $remote, $embed ) {
400  // The full URL possibly with query, as passed to the 'url()' value in CSS
401  $url = $file . $query;
402 
403  // Expand local URLs with absolute paths like /w/index.php to possibly protocol-relative URL, if
404  // wfExpandUrl() is available. (This will not be the case if we're running outside of MW.)
405  if ( self::isLocalUrl( $url ) && function_exists( 'wfExpandUrl' ) ) {
406  return wfExpandUrl( $url, PROTO_RELATIVE );
407  }
408 
409  // Pass thru fully-qualified and protocol-relative URLs and data URIs, as well as local URLs if
410  // we can't expand them.
411  if ( self::isRemoteUrl( $url ) || self::isLocalUrl( $url ) ) {
412  return $url;
413  }
414 
415  if ( $local === false ) {
416  // Assume that all paths are relative to $remote, and make them absolute
417  $url = $remote . '/' . $url;
418  } else {
419  // We drop the query part here and instead make the path relative to $remote
420  $url = "{$remote}/{$file}";
421  // Path to the actual file on the filesystem
422  $localFile = "{$local}/{$file}";
423  if ( file_exists( $localFile ) ) {
424  if ( $embed ) {
425  $data = self::encodeImageAsDataURI( $localFile );
426  if ( $data !== false ) {
427  return $data;
428  }
429  }
430  if ( method_exists( 'OutputPage', 'transformFilePath' ) ) {
431  $url = OutputPage::transformFilePath( $remote, $local, $file );
432  } else {
433  // Add version parameter as the first five hex digits
434  // of the MD5 hash of the file's contents.
435  $url .= '?' . substr( md5_file( $localFile ), 0, 5 );
436  }
437  }
438  // If any of these conditions failed (file missing, we don't want to embed it
439  // or it's not embeddable), return the URL (possibly with ?timestamp part)
440  }
441  if ( function_exists( 'wfRemoveDotSegments' ) ) {
442  $url = wfRemoveDotSegments( $url );
443  }
444  return $url;
445  }
446 
453  public static function minify( $css ) {
454  return trim(
455  str_replace(
456  [ '; ', ': ', ' {', '{ ', ', ', '} ', ';}' ],
457  [ ';', ':', '{', '{', ',', '}', '}' ],
458  preg_replace( [ '/\s+/', '/\/\*.*?\*\//s' ], [ ' ', '' ], $css )
459  )
460  );
461  }
462 }
null for the local wiki Added should default to null in handler for backwards compatibility add a value to it if you want to add a cookie that have to vary cache options can modify $query
Definition: hooks.txt:1555
static remapOne($file, $query, $local, $remote, $embed)
Remap or embed a CSS URL path.
Definition: CSSMin.php:399
const URL_REGEX
Definition: CSSMin.php:41
Apache License January AND DISTRIBUTION Definitions License shall mean the terms and conditions for use
const EMBED_REGEX
Definition: CSSMin.php:42
$source
$value
$files
wfExpandUrl($url, $defaultProto=PROTO_CURRENT)
Expand a potentially local URL to a fully-qualified URL.
const COMMENT_REGEX
Definition: CSSMin.php:43
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Definition: hooks.txt:1936
static array $mimeTypes
List of common image files extensions and MIME-types.
Definition: CSSMin.php:48
static transformFilePath($remotePathPrefix, $localPath, $file)
Utility method for transformResourceFilePath().
static encodeImageAsDataURI($file, $type=null, $ie8Compat=true)
Encode an image file as a data URI.
Definition: CSSMin.php:105
static array static getLocalFileReferences($source, $path)
Get a list of local files referenced in a stylesheet (includes non-existent files).
Definition: CSSMin.php:69
$css
static isLocalUrl($maybeUrl)
Is this CSS rule referencing a local URL?
Definition: CSSMin.php:382
const PROTO_RELATIVE
Definition: Defines.php:225
static serializeStringValue($value)
Serialize a string (escape and quote) for use as a CSS string value.
Definition: CSSMin.php:163
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Definition: distributors.txt:9
static remap($source, $local, $remote, $embedData=true)
Remaps CSS URL paths and automatically embeds data URIs for CSS rules or url() values preceded by an ...
Definition: CSSMin.php:229
static buildUrlValue($url)
Build a CSS 'url()' value for the given URL, quoting parentheses (and other funny characters) and esc...
Definition: CSSMin.php:207
wfRemoveDotSegments($urlPath)
Remove all dot-segments in the provided URL path.
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Definition: injection.txt:35
static getMimeType($file)
Definition: CSSMin.php:178
static minify($css)
Removes whitespace from CSS data.
Definition: CSSMin.php:453
static isRemoteUrl($maybeUrl)
Is this CSS rule referencing a remote URL?
Definition: CSSMin.php:369
static encodeStringAsDataURI($contents, $type, $ie8Compat=true)
Encode file contents as a data URI with chosen MIME type.
Definition: CSSMin.php:133
const DATA_URI_SIZE_LIMIT
Internet Explorer data URI length limit.
Definition: CSSMin.php:40
Transforms CSS data.
Definition: CSSMin.php:30
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Definition: hooks.txt:2491
$matches