includes/resourceloader/ResourceLoaderImage.php

   1 <?php
   2 /**
   3  * Class encapsulating an image used in a ResourceLoaderImageModule.
   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  */
  22
  23 /**
  24  * Class encapsulating an image used in a ResourceLoaderImageModule.
  25  *
  26  * @since 1.25
  27  */
  28 class ResourceLoaderImage {
  29
  30         /**
  31          * Map of allowed file extensions to their MIME types.
  32          * @var array
  33          */
  34         protected static $fileTypes = [
  35                 'svg' => 'image/svg+xml',
  36                 'png' => 'image/png',
  37                 'gif' => 'image/gif',
  38                 'jpg' => 'image/jpg',
  39         ];
  40
  41         /**
  42          * @param string $name Image name
  43          * @param string $module Module name
  44          * @param string|array $descriptor Path to image file, or array structure containing paths
  45          * @param string $basePath Directory to which paths in descriptor refer
  46          * @param array $variants
  47          * @throws InvalidArgumentException
  48          */
  49         public function __construct( $name, $module, $descriptor, $basePath, $variants ) {
  50                 $this->name = $name;
  51                 $this->module = $module;
  52                 $this->descriptor = $descriptor;
  53                 $this->basePath = $basePath;
  54                 $this->variants = $variants;
  55
  56                 // Expand shorthands:
  57                 // [ "en,de,fr" => "foo.svg" ]
  58                 // → [ "en" => "foo.svg", "de" => "foo.svg", "fr" => "foo.svg" ]
  59                 if ( is_array( $this->descriptor ) && isset( $this->descriptor['lang'] ) ) {
  60                         foreach ( array_keys( $this->descriptor['lang'] ) as $langList ) {
  61                                 if ( strpos( $langList, ',' ) !== false ) {
  62                                         $this->descriptor['lang'] += array_fill_keys(
  63                                                 explode( ',', $langList ),
  64                                                 $this->descriptor['lang'][$langList]
  65                                         );
  66                                         unset( $this->descriptor['lang'][$langList] );
  67                                 }
  68                         }
  69                 }
  70
  71                 // Ensure that all files have common extension.
  72                 $extensions = [];
  73                 $descriptor = (array)$descriptor;
  74                 array_walk_recursive( $descriptor, function ( $path ) use ( &$extensions ) {
  75                         $extensions[] = pathinfo( $path, PATHINFO_EXTENSION );
  76                 } );
  77                 $extensions = array_unique( $extensions );
  78                 if ( count( $extensions ) !== 1 ) {
  79                         throw new InvalidArgumentException(
  80                                 "File type for different image files of '$name' not the same"
  81                         );
  82                 }
  83                 $ext = $extensions[0];
  84                 if ( !isset( self::$fileTypes[$ext] ) ) {
  85                         throw new InvalidArgumentException(
  86                                 "Invalid file type for image files of '$name' (valid: svg, png, gif, jpg)"
  87                         );
  88                 }
  89                 $this->extension = $ext;
  90         }
  91
  92         /**
  93          * Get name of this image.
  94          *
  95          * @return string
  96          */
  97         public function getName() {
  98                 return $this->name;
  99         }
 100
 101         /**
 102          * Get name of the module this image belongs to.
 103          *
 104          * @return string
 105          */
 106         public function getModule() {
 107                 return $this->module;
 108         }
 109
 110         /**
 111          * Get the list of variants this image can be converted to.
 112          *
 113          * @return string[]
 114          */
 115         public function getVariants() {
 116                 return array_keys( $this->variants );
 117         }
 118
 119         /**
 120          * Get the path to image file for given context.
 121          *
 122          * @param ResourceLoaderContext $context Any context
 123          * @return string
 124          */
 125         public function getPath( ResourceLoaderContext $context ) {
 126                 $desc = $this->descriptor;
 127                 if ( is_string( $desc ) ) {
 128                         return $this->basePath . '/' . $desc;
 129                 } elseif ( isset( $desc['lang'][$context->getLanguage()] ) ) {
 130                         return $this->basePath . '/' . $desc['lang'][$context->getLanguage()];
 131                 } elseif ( isset( $desc[$context->getDirection()] ) ) {
 132                         return $this->basePath . '/' . $desc[$context->getDirection()];
 133                 } else {
 134                         return $this->basePath . '/' . $desc['default'];
 135                 }
 136         }
 137
 138         /**
 139          * Get the extension of the image.
 140          *
 141          * @param string $format Format to get the extension for, 'original' or 'rasterized'
 142          * @return string Extension without leading dot, e.g. 'png'
 143          */
 144         public function getExtension( $format = 'original' ) {
 145                 if ( $format === 'rasterized' && $this->extension === 'svg' ) {
 146                         return 'png';
 147                 } else {
 148                         return $this->extension;
 149                 }
 150         }
 151
 152         /**
 153          * Get the MIME type of the image.
 154          *
 155          * @param string $format Format to get the MIME type for, 'original' or 'rasterized'
 156          * @return string
 157          */
 158         public function getMimeType( $format = 'original' ) {
 159                 $ext = $this->getExtension( $format );
 160                 return self::$fileTypes[$ext];
 161         }
 162
 163         /**
 164          * Get the load.php URL that will produce this image.
 165          *
 166          * @param ResourceLoaderContext $context Any context
 167          * @param string $script URL to load.php
 168          * @param string|null $variant Variant to get the URL for
 169          * @param string $format Format to get the URL for, 'original' or 'rasterized'
 170          * @return string
 171          */
 172         public function getUrl( ResourceLoaderContext $context, $script, $variant, $format ) {
 173                 $query = [
 174                         'modules' => $this->getModule(),
 175                         'image' => $this->getName(),
 176                         'variant' => $variant,
 177                         'format' => $format,
 178                         'lang' => $context->getLanguage(),
 179                         'skin' => $context->getSkin(),
 180                         'version' => $context->getVersion(),
 181                 ];
 182
 183                 return wfAppendQuery( $script, $query );
 184         }
 185
 186         /**
 187          * Get the data: URI that will produce this image.
 188          *
 189          * @param ResourceLoaderContext $context Any context
 190          * @param string|null $variant Variant to get the URI for
 191          * @param string $format Format to get the URI for, 'original' or 'rasterized'
 192          * @return string
 193          */
 194         public function getDataUri( ResourceLoaderContext $context, $variant, $format ) {
 195                 $type = $this->getMimeType( $format );
 196                 $contents = $this->getImageData( $context, $variant, $format );
 197                 return CSSMin::encodeStringAsDataURI( $contents, $type );
 198         }
 199
 200         /**
 201          * Get actual image data for this image. This can be saved to a file or sent to the browser to
 202          * produce the converted image.
 203          *
 204          * Call getExtension() or getMimeType() with the same $format argument to learn what file type the
 205          * returned data uses.
 206          *
 207          * @param ResourceLoaderContext $context Image context, or any context if $variant and $format
 208          *     given.
 209          * @param string|null $variant Variant to get the data for. Optional; if given, overrides the data
 210          *     from $context.
 211          * @param string $format Format to get the data for, 'original' or 'rasterized'. Optional; if
 212          *     given, overrides the data from $context.
 213          * @return string|false Possibly binary image data, or false on failure
 214          * @throws MWException If the image file doesn't exist
 215          */
 216         public function getImageData( ResourceLoaderContext $context, $variant = false, $format = false ) {
 217                 if ( $variant === false ) {
 218                         $variant = $context->getVariant();
 219                 }
 220                 if ( $format === false ) {
 221                         $format = $context->getFormat();
 222                 }
 223
 224                 $path = $this->getPath( $context );
 225                 if ( !file_exists( $path ) ) {
 226                         throw new MWException( "File '$path' does not exist" );
 227                 }
 228
 229                 if ( $this->getExtension() !== 'svg' ) {
 230                         return file_get_contents( $path );
 231                 }
 232
 233                 if ( $variant && isset( $this->variants[$variant] ) ) {
 234                         $data = $this->variantize( $this->variants[$variant], $context );
 235                 } else {
 236                         $data = file_get_contents( $path );
 237                 }
 238
 239                 if ( $format === 'rasterized' ) {
 240                         $data = $this->rasterize( $data );
 241                         if ( !$data ) {
 242                                 wfDebugLog( 'ResourceLoaderImage', __METHOD__ . " failed to rasterize for $path" );
 243                         }
 244                 }
 245
 246                 return $data;
 247         }
 248
 249         /**
 250          * Send response headers (using the header() function) that are necessary to correctly serve the
 251          * image data for this image, as returned by getImageData().
 252          *
 253          * Note that the headers are independent of the language or image variant.
 254          *
 255          * @param ResourceLoaderContext $context Image context
 256          */
 257         public function sendResponseHeaders( ResourceLoaderContext $context ) {
 258                 $format = $context->getFormat();
 259                 $mime = $this->getMimeType( $format );
 260                 $filename = $this->getName() . '.' . $this->getExtension( $format );
 261
 262                 header( 'Content-Type: ' . $mime );
 263                 header( 'Content-Disposition: ' .
 264                         FileBackend::makeContentDisposition( 'inline', $filename ) );
 265         }
 266
 267         /**
 268          * Convert this image, which is assumed to be SVG, to given variant.
 269          *
 270          * @param array $variantConf Array with a 'color' key, its value will be used as fill color
 271          * @param ResourceLoaderContext $context Image context
 272          * @return string New SVG file data
 273          */
 274         protected function variantize( $variantConf, ResourceLoaderContext $context ) {
 275                 $dom = new DomDocument;
 276                 $dom->loadXML( file_get_contents( $this->getPath( $context ) ) );
 277                 $root = $dom->documentElement;
 278                 $wrapper = $dom->createElement( 'g' );
 279                 while ( $root->firstChild ) {
 280                         $wrapper->appendChild( $root->firstChild );
 281                 }
 282                 $root->appendChild( $wrapper );
 283                 $wrapper->setAttribute( 'fill', $variantConf['color'] );
 284                 return $dom->saveXML();
 285         }
 286
 287         /**
 288          * Massage the SVG image data for converters which don't understand some path data syntax.
 289          *
 290          * This is necessary for rsvg and ImageMagick when compiled with rsvg support.
 291          * Upstream bug is https://bugzilla.gnome.org/show_bug.cgi?id=620923, fixed 2014-11-10, so
 292          * this will be needed for a while. (T76852)
 293          *
 294          * @param string $svg SVG image data
 295          * @return string Massaged SVG image data
 296          */
 297         protected function massageSvgPathdata( $svg ) {
 298                 $dom = new DomDocument;
 299                 $dom->loadXML( $svg );
 300                 foreach ( $dom->getElementsByTagName( 'path' ) as $node ) {
 301                         $pathData = $node->getAttribute( 'd' );
 302                         // Make sure there is at least one space between numbers, and that leading zero is not omitted.
 303                         // rsvg has issues with syntax like "M-1-2" and "M.445.483" and especially "M-.445-.483".
 304                         $pathData = preg_replace( '/(-?)(\d*\.\d+|\d+)/', ' ${1}0$2 ', $pathData );
 305                         // Strip unnecessary leading zeroes for prettiness, not strictly necessary
 306                         $pathData = preg_replace( '/([ -])0(\d)/', '$1$2', $pathData );
 307                         $node->setAttribute( 'd', $pathData );
 308                 }
 309                 return $dom->saveXML();
 310         }
 311
 312         /**
 313          * Convert passed image data, which is assumed to be SVG, to PNG.
 314          *
 315          * @param string $svg SVG image data
 316          * @return string|bool PNG image data, or false on failure
 317          */
 318         protected function rasterize( $svg ) {
 319                 /**
 320                  * This code should be factored out to a separate method on SvgHandler, or perhaps a separate
 321                  * class, with a separate set of configuration settings.
 322                  *
 323                  * This is a distinct use case from regular SVG rasterization:
 324                  * * We can skip many sanity and security checks (as the images come from a trusted source,
 325                  *   rather than from the user).
 326                  * * We need to provide extra options to some converters to achieve acceptable quality for very
 327                  *   small images, which might cause performance issues in the general case.
 328                  * * We want to directly pass image data to the converter, rather than a file path.
 329                  *
 330                  * See https://phabricator.wikimedia.org/T76473#801446 for examples of what happens with the
 331                  * default settings.
 332                  *
 333                  * For now, we special-case rsvg (used in WMF production) and do a messy workaround for other
 334                  * converters.
 335                  */
 336
 337                 global $wgSVGConverter, $wgSVGConverterPath;
 338
 339                 $svg = $this->massageSvgPathdata( $svg );
 340
 341                 // Sometimes this might be 'rsvg-secure'. Long as it's rsvg.
 342                 if ( strpos( $wgSVGConverter, 'rsvg' ) === 0 ) {
 343                         $command = 'rsvg-convert';
 344                         if ( $wgSVGConverterPath ) {
 345                                 $command = wfEscapeShellArg( "$wgSVGConverterPath/" ) . $command;
 346                         }
 347
 348                         $process = proc_open(
 349                                 $command,
 350                                 [ 0 => [ 'pipe', 'r' ], 1 => [ 'pipe', 'w' ] ],
 351                                 $pipes
 352                         );
 353
 354                         if ( is_resource( $process ) ) {
 355                                 fwrite( $pipes[0], $svg );
 356                                 fclose( $pipes[0] );
 357                                 $png = stream_get_contents( $pipes[1] );
 358                                 fclose( $pipes[1] );
 359                                 proc_close( $process );
 360
 361                                 return $png ?: false;
 362                         }
 363                         return false;
 364
 365                 } else {
 366                         // Write input to and read output from a temporary file
 367                         $tempFilenameSvg = tempnam( wfTempDir(), 'ResourceLoaderImage' );
 368                         $tempFilenamePng = tempnam( wfTempDir(), 'ResourceLoaderImage' );
 369
 370                         file_put_contents( $tempFilenameSvg, $svg );
 371
 372                         $metadata = SVGMetadataExtractor::getMetadata( $tempFilenameSvg );
 373                         if ( !isset( $metadata['width'] ) || !isset( $metadata['height'] ) ) {
 374                                 unlink( $tempFilenameSvg );
 375                                 return false;
 376                         }
 377
 378                         $handler = new SvgHandler;
 379                         $res = $handler->rasterize(
 380                                 $tempFilenameSvg,
 381                                 $tempFilenamePng,
 382                                 $metadata['width'],
 383                                 $metadata['height']
 384                         );
 385                         unlink( $tempFilenameSvg );
 386
 387                         $png = null;
 388                         if ( $res === true ) {
 389                                 $png = file_get_contents( $tempFilenamePng );
 390                                 unlink( $tempFilenamePng );
 391                         }
 392
 393                         return $png ?: false;
 394                 }
 395         }
 396 }