includes/media/SvgHandler.php

   1 <?php
   2 /**
   3  * Handler for SVG images.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Media
  22  */
  23 use Wikimedia\ScopedCallback;
  24
  25 /**
  26  * Handler for SVG images.
  27  *
  28  * @ingroup Media
  29  */
  30 class SvgHandler extends ImageHandler {
  31         const SVG_METADATA_VERSION = 2;
  32
  33         /** @var array A list of metadata tags that can be converted
  34          *  to the commonly used exif tags. This allows messages
  35          *  to be reused, and consistent tag names for {{#formatmetadata:..}}
  36          */
  37         private static $metaConversion = [
  38                 'originalwidth' => 'ImageWidth',
  39                 'originalheight' => 'ImageLength',
  40                 'description' => 'ImageDescription',
  41                 'title' => 'ObjectName',
  42         ];
  43
  44         function isEnabled() {
  45                 global $wgSVGConverters, $wgSVGConverter;
  46                 if ( !isset( $wgSVGConverters[$wgSVGConverter] ) ) {
  47                         wfDebug( "\$wgSVGConverter is invalid, disabling SVG rendering.\n" );
  48
  49                         return false;
  50                 } else {
  51                         return true;
  52                 }
  53         }
  54
  55         public function mustRender( $file ) {
  56                 return true;
  57         }
  58
  59         function isVectorized( $file ) {
  60                 return true;
  61         }
  62
  63         /**
  64          * @param File $file
  65          * @return bool
  66          */
  67         function isAnimatedImage( $file ) {
  68                 # @todo Detect animated SVGs
  69                 $metadata = $file->getMetadata();
  70                 if ( $metadata ) {
  71                         $metadata = $this->unpackMetadata( $metadata );
  72                         if ( isset( $metadata['animated'] ) ) {
  73                                 return $metadata['animated'];
  74                         }
  75                 }
  76
  77                 return false;
  78         }
  79
  80         /**
  81          * Which languages (systemLanguage attribute) is supported.
  82          *
  83          * @note This list is not guaranteed to be exhaustive.
  84          * To avoid OOM errors, we only look at first bit of a file.
  85          * Thus all languages on this list are present in the file,
  86          * but its possible for the file to have a language not on
  87          * this list.
  88          *
  89          * @param File $file
  90          * @return array Array of language codes, or empty if no language switching supported.
  91          */
  92         public function getAvailableLanguages( File $file ) {
  93                 $metadata = $file->getMetadata();
  94                 $langList = [];
  95                 if ( $metadata ) {
  96                         $metadata = $this->unpackMetadata( $metadata );
  97                         if ( isset( $metadata['translations'] ) ) {
  98                                 foreach ( $metadata['translations'] as $lang => $langType ) {
  99                                         if ( $langType === SVGReader::LANG_FULL_MATCH ) {
 100                                                 $langList[] = strtolower( $lang );
 101                                         }
 102                                 }
 103                         }
 104                 }
 105                 return array_unique( $langList );
 106         }
 107
 108         /**
 109          * SVG's systemLanguage matching rules state:
 110          * 'The `systemLanguage` attribute ... [e]valuates to "true" if one of the languages indicated
 111          * by user preferences exactly equals one of the languages given in the value of this parameter,
 112          * or if one of the languages indicated by user preferences exactly equals a prefix of one of
 113          * the languages given in the value of this parameter such that the first tag character
 114          * following the prefix is "-".'
 115          *
 116          * Return the first element of $svgLanguages that matches $userPreferredLanguage
 117          *
 118          * @see https://www.w3.org/TR/SVG/struct.html#SystemLanguageAttribute
 119          * @param string $userPreferredLanguage
 120          * @param array $svgLanguages
 121          * @return string|null
 122          */
 123         public function getMatchedLanguage( $userPreferredLanguage, array $svgLanguages ) {
 124                 foreach ( $svgLanguages as $svgLang ) {
 125                         if ( strcasecmp( $svgLang, $userPreferredLanguage ) === 0 ) {
 126                                 return $svgLang;
 127                         }
 128                         $trimmedSvgLang = $svgLang;
 129                         while ( strpos( $trimmedSvgLang, '-' ) !== false ) {
 130                                 $trimmedSvgLang = substr( $trimmedSvgLang, 0, strrpos( $trimmedSvgLang, '-' ) );
 131                                 if ( strcasecmp( $trimmedSvgLang, $userPreferredLanguage ) === 0 ) {
 132                                         return $svgLang;
 133                                 }
 134                         }
 135                 }
 136                 return null;
 137         }
 138
 139         /**
 140          * What language to render file in if none selected
 141          *
 142          * @param File $file Language code
 143          * @return string
 144          */
 145         public function getDefaultRenderLanguage( File $file ) {
 146                 return 'en';
 147         }
 148
 149         /**
 150          * We do not support making animated svg thumbnails
 151          * @param File $file
 152          * @return bool
 153          */
 154         function canAnimateThumbnail( $file ) {
 155                 return false;
 156         }
 157
 158         /**
 159          * @param File $image
 160          * @param array &$params
 161          * @return bool
 162          */
 163         function normaliseParams( $image, &$params ) {
 164                 global $wgSVGMaxSize;
 165                 if ( !parent::normaliseParams( $image, $params ) ) {
 166                         return false;
 167                 }
 168                 # Don't make an image bigger than wgMaxSVGSize on the smaller side
 169                 if ( $params['physicalWidth'] <= $params['physicalHeight'] ) {
 170                         if ( $params['physicalWidth'] > $wgSVGMaxSize ) {
 171                                 $srcWidth = $image->getWidth( $params['page'] );
 172                                 $srcHeight = $image->getHeight( $params['page'] );
 173                                 $params['physicalWidth'] = $wgSVGMaxSize;
 174                                 $params['physicalHeight'] = File::scaleHeight( $srcWidth, $srcHeight, $wgSVGMaxSize );
 175                         }
 176                 } else {
 177                         if ( $params['physicalHeight'] > $wgSVGMaxSize ) {
 178                                 $srcWidth = $image->getWidth( $params['page'] );
 179                                 $srcHeight = $image->getHeight( $params['page'] );
 180                                 $params['physicalWidth'] = File::scaleHeight( $srcHeight, $srcWidth, $wgSVGMaxSize );
 181                                 $params['physicalHeight'] = $wgSVGMaxSize;
 182                         }
 183                 }
 184
 185                 return true;
 186         }
 187
 188         /**
 189          * @param File $image
 190          * @param string $dstPath
 191          * @param string $dstUrl
 192          * @param array $params
 193          * @param int $flags
 194          * @return bool|MediaTransformError|ThumbnailImage|TransformParameterError
 195          */
 196         function doTransform( $image, $dstPath, $dstUrl, $params, $flags = 0 ) {
 197                 if ( !$this->normaliseParams( $image, $params ) ) {
 198                         return new TransformParameterError( $params );
 199                 }
 200                 $clientWidth = $params['width'];
 201                 $clientHeight = $params['height'];
 202                 $physicalWidth = $params['physicalWidth'];
 203                 $physicalHeight = $params['physicalHeight'];
 204                 $lang = $params['lang'] ?? $this->getDefaultRenderLanguage( $image );
 205
 206                 if ( $flags & self::TRANSFORM_LATER ) {
 207                         return new ThumbnailImage( $image, $dstUrl, $dstPath, $params );
 208                 }
 209
 210                 $metadata = $this->unpackMetadata( $image->getMetadata() );
 211                 if ( isset( $metadata['error'] ) ) { // sanity check
 212                         $err = wfMessage( 'svg-long-error', $metadata['error']['message'] );
 213
 214                         return new MediaTransformError( 'thumbnail_error', $clientWidth, $clientHeight, $err );
 215                 }
 216
 217                 if ( !wfMkdirParents( dirname( $dstPath ), null, __METHOD__ ) ) {
 218                         return new MediaTransformError( 'thumbnail_error', $clientWidth, $clientHeight,
 219                                 wfMessage( 'thumbnail_dest_directory' ) );
 220                 }
 221
 222                 $srcPath = $image->getLocalRefPath();
 223                 if ( $srcPath === false ) { // Failed to get local copy
 224                         wfDebugLog( 'thumbnail',
 225                                 sprintf( 'Thumbnail failed on %s: could not get local copy of "%s"',
 226                                         wfHostname(), $image->getName() ) );
 227
 228                         return new MediaTransformError( 'thumbnail_error',
 229                                 $params['width'], $params['height'],
 230                                 wfMessage( 'filemissing' )
 231                         );
 232                 }
 233
 234                 // Make a temp dir with a symlink to the local copy in it.
 235                 // This plays well with rsvg-convert policy for external entities.
 236                 // https://git.gnome.org/browse/librsvg/commit/?id=f01aded72c38f0e18bc7ff67dee800e380251c8e
 237                 $tmpDir = wfTempDir() . '/svg_' . wfRandomString( 24 );
 238                 $lnPath = "$tmpDir/" . basename( $srcPath );
 239                 $ok = mkdir( $tmpDir, 0771 );
 240                 if ( !$ok ) {
 241                         wfDebugLog( 'thumbnail',
 242                                 sprintf( 'Thumbnail failed on %s: could not create temporary directory %s',
 243                                         wfHostname(), $tmpDir ) );
 244                         return new MediaTransformError( 'thumbnail_error',
 245                                 $params['width'], $params['height'],
 246                                 wfMessage( 'thumbnail-temp-create' )->text()
 247                         );
 248                 }
 249                 $ok = symlink( $srcPath, $lnPath );
 250                 /** @noinspection PhpUnusedLocalVariableInspection */
 251                 $cleaner = new ScopedCallback( function () use ( $tmpDir, $lnPath ) {
 252                         Wikimedia\suppressWarnings();
 253                         unlink( $lnPath );
 254                         rmdir( $tmpDir );
 255                         Wikimedia\restoreWarnings();
 256                 } );
 257                 if ( !$ok ) {
 258                         wfDebugLog( 'thumbnail',
 259                                 sprintf( 'Thumbnail failed on %s: could not link %s to %s',
 260                                         wfHostname(), $lnPath, $srcPath ) );
 261                         return new MediaTransformError( 'thumbnail_error',
 262                                 $params['width'], $params['height'],
 263                                 wfMessage( 'thumbnail-temp-create' )
 264                         );
 265                 }
 266
 267                 $status = $this->rasterize( $lnPath, $dstPath, $physicalWidth, $physicalHeight, $lang );
 268                 if ( $status === true ) {
 269                         return new ThumbnailImage( $image, $dstUrl, $dstPath, $params );
 270                 } else {
 271                         return $status; // MediaTransformError
 272                 }
 273         }
 274
 275         /**
 276          * Transform an SVG file to PNG
 277          * This function can be called outside of thumbnail contexts
 278          * @param string $srcPath
 279          * @param string $dstPath
 280          * @param string $width
 281          * @param string $height
 282          * @param bool|string $lang Language code of the language to render the SVG in
 283          * @throws MWException
 284          * @return bool|MediaTransformError
 285          */
 286         public function rasterize( $srcPath, $dstPath, $width, $height, $lang = false ) {
 287                 global $wgSVGConverters, $wgSVGConverter, $wgSVGConverterPath;
 288                 $err = false;
 289                 $retval = '';
 290                 if ( isset( $wgSVGConverters[$wgSVGConverter] ) ) {
 291                         if ( is_array( $wgSVGConverters[$wgSVGConverter] ) ) {
 292                                 // This is a PHP callable
 293                                 $func = $wgSVGConverters[$wgSVGConverter][0];
 294                                 if ( !is_callable( $func ) ) {
 295                                         throw new MWException( "$func is not callable" );
 296                                 }
 297                                 $err = $func( $srcPath,
 298                                         $dstPath,
 299                                         $width,
 300                                         $height,
 301                                         $lang,
 302                                         ...array_slice( $wgSVGConverters[$wgSVGConverter], 1 )
 303                                 );
 304                                 $retval = (bool)$err;
 305                         } else {
 306                                 // External command
 307                                 $cmd = str_replace(
 308                                         [ '$path/', '$width', '$height', '$input', '$output' ],
 309                                         [ $wgSVGConverterPath ? wfEscapeShellArg( "$wgSVGConverterPath/" ) : "",
 310                                                 intval( $width ),
 311                                                 intval( $height ),
 312                                                 wfEscapeShellArg( $srcPath ),
 313                                                 wfEscapeShellArg( $dstPath ) ],
 314                                         $wgSVGConverters[$wgSVGConverter]
 315                                 );
 316
 317                                 $env = [];
 318                                 if ( $lang !== false ) {
 319                                         $env['LANG'] = $lang;
 320                                 }
 321
 322                                 wfDebug( __METHOD__ . ": $cmd\n" );
 323                                 $err = wfShellExecWithStderr( $cmd, $retval, $env );
 324                         }
 325                 }
 326                 $removed = $this->removeBadFile( $dstPath, $retval );
 327                 if ( $retval != 0 || $removed ) {
 328                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 329                         return new MediaTransformError( 'thumbnail_error', $width, $height, $err );
 330                 }
 331
 332                 return true;
 333         }
 334
 335         public static function rasterizeImagickExt( $srcPath, $dstPath, $width, $height ) {
 336                 $im = new Imagick( $srcPath );
 337                 $im->setImageFormat( 'png' );
 338                 $im->setBackgroundColor( 'transparent' );
 339                 $im->setImageDepth( 8 );
 340
 341                 if ( !$im->thumbnailImage( intval( $width ), intval( $height ), /* fit */ false ) ) {
 342                         return 'Could not resize image';
 343                 }
 344                 if ( !$im->writeImage( $dstPath ) ) {
 345                         return "Could not write to $dstPath";
 346                 }
 347         }
 348
 349         /**
 350          * @param File|FSFile $file
 351          * @param string $path Unused
 352          * @param bool|array $metadata
 353          * @return array
 354          */
 355         function getImageSize( $file, $path, $metadata = false ) {
 356                 if ( $metadata === false && $file instanceof File ) {
 357                         $metadata = $file->getMetadata();
 358                 }
 359                 $metadata = $this->unpackMetadata( $metadata );
 360
 361                 if ( isset( $metadata['width'] ) && isset( $metadata['height'] ) ) {
 362                         return [ $metadata['width'], $metadata['height'], 'SVG',
 363                                 "width=\"{$metadata['width']}\" height=\"{$metadata['height']}\"" ];
 364                 } else { // error
 365                         return [ 0, 0, 'SVG', "width=\"0\" height=\"0\"" ];
 366                 }
 367         }
 368
 369         function getThumbType( $ext, $mime, $params = null ) {
 370                 return [ 'png', 'image/png' ];
 371         }
 372
 373         /**
 374          * Subtitle for the image. Different from the base
 375          * class so it can be denoted that SVG's have
 376          * a "nominal" resolution, and not a fixed one,
 377          * as well as so animation can be denoted.
 378          *
 379          * @param File $file
 380          * @return string
 381          */
 382         function getLongDesc( $file ) {
 383                 global $wgLang;
 384
 385                 $metadata = $this->unpackMetadata( $file->getMetadata() );
 386                 if ( isset( $metadata['error'] ) ) {
 387                         return wfMessage( 'svg-long-error', $metadata['error']['message'] )->text();
 388                 }
 389
 390                 $size = $wgLang->formatSize( $file->getSize() );
 391
 392                 if ( $this->isAnimatedImage( $file ) ) {
 393                         $msg = wfMessage( 'svg-long-desc-animated' );
 394                 } else {
 395                         $msg = wfMessage( 'svg-long-desc' );
 396                 }
 397
 398                 $msg->numParams( $file->getWidth(), $file->getHeight() )->params( $size );
 399
 400                 return $msg->parse();
 401         }
 402
 403         /**
 404          * @param File|FSFile $file
 405          * @param string $filename
 406          * @return string Serialised metadata
 407          */
 408         function getMetadata( $file, $filename ) {
 409                 $metadata = [ 'version' => self::SVG_METADATA_VERSION ];
 410                 try {
 411                         $metadata += SVGMetadataExtractor::getMetadata( $filename );
 412                 } catch ( Exception $e ) { // @todo SVG specific exceptions
 413                         // File not found, broken, etc.
 414                         $metadata['error'] = [
 415                                 'message' => $e->getMessage(),
 416                                 'code' => $e->getCode()
 417                         ];
 418                         wfDebug( __METHOD__ . ': ' . $e->getMessage() . "\n" );
 419                 }
 420
 421                 return serialize( $metadata );
 422         }
 423
 424         function unpackMetadata( $metadata ) {
 425                 Wikimedia\suppressWarnings();
 426                 $unser = unserialize( $metadata );
 427                 Wikimedia\restoreWarnings();
 428                 if ( isset( $unser['version'] ) && $unser['version'] == self::SVG_METADATA_VERSION ) {
 429                         return $unser;
 430                 } else {
 431                         return false;
 432                 }
 433         }
 434
 435         function getMetadataType( $image ) {
 436                 return 'parsed-svg';
 437         }
 438
 439         function isMetadataValid( $image, $metadata ) {
 440                 $meta = $this->unpackMetadata( $metadata );
 441                 if ( $meta === false ) {
 442                         return self::METADATA_BAD;
 443                 }
 444                 if ( !isset( $meta['originalWidth'] ) ) {
 445                         // Old but compatible
 446                         return self::METADATA_COMPATIBLE;
 447                 }
 448
 449                 return self::METADATA_GOOD;
 450         }
 451
 452         protected function visibleMetadataFields() {
 453                 $fields = [ 'objectname', 'imagedescription' ];
 454
 455                 return $fields;
 456         }
 457
 458         /**
 459          * @param File $file
 460          * @param bool|IContextSource $context Context to use (optional)
 461          * @return array|bool
 462          */
 463         function formatMetadata( $file, $context = false ) {
 464                 $result = [
 465                         'visible' => [],
 466                         'collapsed' => []
 467                 ];
 468                 $metadata = $file->getMetadata();
 469                 if ( !$metadata ) {
 470                         return false;
 471                 }
 472                 $metadata = $this->unpackMetadata( $metadata );
 473                 if ( !$metadata || isset( $metadata['error'] ) ) {
 474                         return false;
 475                 }
 476
 477                 /* @todo Add a formatter
 478                 $format = new FormatSVG( $metadata );
 479                 $formatted = $format->getFormattedData();
 480                 */
 481
 482                 // Sort fields into visible and collapsed
 483                 $visibleFields = $this->visibleMetadataFields();
 484
 485                 $showMeta = false;
 486                 foreach ( $metadata as $name => $value ) {
 487                         $tag = strtolower( $name );
 488                         if ( isset( self::$metaConversion[$tag] ) ) {
 489                                 $tag = strtolower( self::$metaConversion[$tag] );
 490                         } else {
 491                                 // Do not output other metadata not in list
 492                                 continue;
 493                         }
 494                         $showMeta = true;
 495                         self::addMeta( $result,
 496                                 in_array( $tag, $visibleFields ) ? 'visible' : 'collapsed',
 497                                 'exif',
 498                                 $tag,
 499                                 $value
 500                         );
 501                 }
 502
 503                 return $showMeta ? $result : false;
 504         }
 505
 506         /**
 507          * @param string $name Parameter name
 508          * @param mixed $value Parameter value
 509          * @return bool Validity
 510          */
 511         public function validateParam( $name, $value ) {
 512                 if ( in_array( $name, [ 'width', 'height' ] ) ) {
 513                         // Reject negative heights, widths
 514                         return ( $value > 0 );
 515                 } elseif ( $name == 'lang' ) {
 516                         // Validate $code
 517                         if ( $value === '' || !Language::isValidCode( $value ) ) {
 518                                 return false;
 519                         }
 520
 521                         return true;
 522                 }
 523
 524                 // Only lang, width and height are acceptable keys
 525                 return false;
 526         }
 527
 528         /**
 529          * @param array $params Name=>value pairs of parameters
 530          * @return string Filename to use
 531          */
 532         public function makeParamString( $params ) {
 533                 $lang = '';
 534                 if ( isset( $params['lang'] ) && $params['lang'] !== 'en' ) {
 535                         $lang = 'lang' . strtolower( $params['lang'] ) . '-';
 536                 }
 537                 if ( !isset( $params['width'] ) ) {
 538                         return false;
 539                 }
 540
 541                 return "$lang{$params['width']}px";
 542         }
 543
 544         public function parseParamString( $str ) {
 545                 $m = false;
 546                 if ( preg_match( '/^lang([a-z]+(?:-[a-z]+)*)-(\d+)px$/i', $str, $m ) ) {
 547                         return [ 'width' => array_pop( $m ), 'lang' => $m[1] ];
 548                 } elseif ( preg_match( '/^(\d+)px$/', $str, $m ) ) {
 549                         return [ 'width' => $m[1], 'lang' => 'en' ];
 550                 } else {
 551                         return false;
 552                 }
 553         }
 554
 555         public function getParamMap() {
 556                 return [ 'img_lang' => 'lang', 'img_width' => 'width' ];
 557         }
 558
 559         /**
 560          * @param array $params
 561          * @return array
 562          */
 563         function getScriptParams( $params ) {
 564                 $scriptParams = [ 'width' => $params['width'] ];
 565                 if ( isset( $params['lang'] ) ) {
 566                         $scriptParams['lang'] = $params['lang'];
 567                 }
 568
 569                 return $scriptParams;
 570         }
 571
 572         public function getCommonMetaArray( File $file ) {
 573                 $metadata = $file->getMetadata();
 574                 if ( !$metadata ) {
 575                         return [];
 576                 }
 577                 $metadata = $this->unpackMetadata( $metadata );
 578                 if ( !$metadata || isset( $metadata['error'] ) ) {
 579                         return [];
 580                 }
 581                 $stdMetadata = [];
 582                 foreach ( $metadata as $name => $value ) {
 583                         $tag = strtolower( $name );
 584                         if ( $tag === 'originalwidth' || $tag === 'originalheight' ) {
 585                                 // Skip these. In the exif metadata stuff, it is assumed these
 586                                 // are measured in px, which is not the case here.
 587                                 continue;
 588                         }
 589                         if ( isset( self::$metaConversion[$tag] ) ) {
 590                                 $tag = self::$metaConversion[$tag];
 591                                 $stdMetadata[$tag] = $value;
 592                         }
 593                 }
 594
 595                 return $stdMetadata;
 596         }
 597 }