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 use MediaWiki\Shell\Shell;
  24
  25 /**
  26  * Class encapsulating an image used in a ResourceLoaderImageModule.
  27  *
  28  * @since 1.25
  29  */
  30 class ResourceLoaderImage {
  31
  32         /**
  33          * Map of allowed file extensions to their MIME types.
  34          * @var array
  35          */
  36         protected static $fileTypes = [
  37                 'svg' => 'image/svg+xml',
  38                 'png' => 'image/png',
  39                 'gif' => 'image/gif',
  40                 'jpg' => 'image/jpg',
  41         ];
  42
  43         /**
  44          * @param string $name Image name
  45          * @param string $module Module name
  46          * @param string|array $descriptor Path to image file, or array structure containing paths
  47          * @param string $basePath Directory to which paths in descriptor refer
  48          * @param array $variants
  49          * @param string|null $defaultColor of the base variant
  50          * @throws InvalidArgumentException
  51          */
  52         public function __construct( $name, $module, $descriptor, $basePath, $variants,
  53                 $defaultColor = null
  54         ) {
  55                 $this->name = $name;
  56                 $this->module = $module;
  57                 $this->descriptor = $descriptor;
  58                 $this->basePath = $basePath;
  59                 $this->variants = $variants;
  60                 $this->defaultColor = $defaultColor;
  61
  62                 // Expand shorthands:
  63                 // [ "en,de,fr" => "foo.svg" ]
  64                 // → [ "en" => "foo.svg", "de" => "foo.svg", "fr" => "foo.svg" ]
  65                 if ( is_array( $this->descriptor ) && isset( $this->descriptor['lang'] ) ) {
  66                         foreach ( array_keys( $this->descriptor['lang'] ) as $langList ) {
  67                                 if ( strpos( $langList, ',' ) !== false ) {
  68                                         $this->descriptor['lang'] += array_fill_keys(
  69                                                 explode( ',', $langList ),
  70                                                 $this->descriptor['lang'][$langList]
  71                                         );
  72                                         unset( $this->descriptor['lang'][$langList] );
  73                                 }
  74                         }
  75                 }
  76                 // Remove 'deprecated' key
  77                 if ( is_array( $this->descriptor ) ) {
  78                         unset( $this->descriptor['deprecated'] );
  79                 }
  80
  81                 // Ensure that all files have common extension.
  82                 $extensions = [];
  83                 $descriptor = (array)$this->descriptor;
  84                 array_walk_recursive( $descriptor, function ( $path ) use ( &$extensions ) {
  85                         $extensions[] = pathinfo( $path, PATHINFO_EXTENSION );
  86                 } );
  87                 $extensions = array_unique( $extensions );
  88                 if ( count( $extensions ) !== 1 ) {
  89                         throw new InvalidArgumentException(
  90                                 "File type for different image files of '$name' not the same in module '$module'"
  91                         );
  92                 }
  93                 $ext = $extensions[0];
  94                 if ( !isset( self::$fileTypes[$ext] ) ) {
  95                         throw new InvalidArgumentException(
  96                                 "Invalid file type for image files of '$name' (valid: svg, png, gif, jpg) in module '$module'"
  97                         );
  98                 }
  99                 $this->extension = $ext;
 100         }
 101
 102         /**
 103          * Get name of this image.
 104          *
 105          * @return string
 106          */
 107         public function getName() {
 108                 return $this->name;
 109         }
 110
 111         /**
 112          * Get name of the module this image belongs to.
 113          *
 114          * @return string
 115          */
 116         public function getModule() {
 117                 return $this->module;
 118         }
 119
 120         /**
 121          * Get the list of variants this image can be converted to.
 122          *
 123          * @return string[]
 124          */
 125         public function getVariants() {
 126                 return array_keys( $this->variants );
 127         }
 128
 129         /**
 130          * Get the path to image file for given context.
 131          *
 132          * @param ResourceLoaderContext $context Any context
 133          * @return string
 134          */
 135         public function getPath( ResourceLoaderContext $context ) {
 136                 $desc = $this->descriptor;
 137                 if ( is_string( $desc ) ) {
 138                         return $this->basePath . '/' . $desc;
 139                 }
 140                 if ( isset( $desc['lang'] ) ) {
 141                         $contextLang = $context->getLanguage();
 142                         if ( isset( $desc['lang'][$contextLang] ) ) {
 143                                 return $this->basePath . '/' . $desc['lang'][$contextLang];
 144                         }
 145                         $fallbacks = Language::getFallbacksFor( $contextLang, Language::STRICT_FALLBACKS );
 146                         foreach ( $fallbacks as $lang ) {
 147                                 if ( isset( $desc['lang'][$lang] ) ) {
 148                                         return $this->basePath . '/' . $desc['lang'][$lang];
 149                                 }
 150                         }
 151                 }
 152                 if ( isset( $desc[$context->getDirection()] ) ) {
 153                         return $this->basePath . '/' . $desc[$context->getDirection()];
 154                 }
 155                 return $this->basePath . '/' . $desc['default'];
 156         }
 157
 158         /**
 159          * Get the extension of the image.
 160          *
 161          * @param string $format Format to get the extension for, 'original' or 'rasterized'
 162          * @return string Extension without leading dot, e.g. 'png'
 163          */
 164         public function getExtension( $format = 'original' ) {
 165                 if ( $format === 'rasterized' && $this->extension === 'svg' ) {
 166                         return 'png';
 167                 }
 168                 return $this->extension;
 169         }
 170
 171         /**
 172          * Get the MIME type of the image.
 173          *
 174          * @param string $format Format to get the MIME type for, 'original' or 'rasterized'
 175          * @return string
 176          */
 177         public function getMimeType( $format = 'original' ) {
 178                 $ext = $this->getExtension( $format );
 179                 return self::$fileTypes[$ext];
 180         }
 181
 182         /**
 183          * Get the load.php URL that will produce this image.
 184          *
 185          * @param ResourceLoaderContext $context Any context
 186          * @param string $script URL to load.php
 187          * @param string|null $variant Variant to get the URL for
 188          * @param string $format Format to get the URL for, 'original' or 'rasterized'
 189          * @return string
 190          */
 191         public function getUrl( ResourceLoaderContext $context, $script, $variant, $format ) {
 192                 $query = [
 193                         'modules' => $this->getModule(),
 194                         'image' => $this->getName(),
 195                         'variant' => $variant,
 196                         'format' => $format,
 197                         'lang' => $context->getLanguage(),
 198                         'skin' => $context->getSkin(),
 199                         'version' => $context->getVersion(),
 200                 ];
 201
 202                 return wfAppendQuery( $script, $query );
 203         }
 204
 205         /**
 206          * Get the data: URI that will produce this image.
 207          *
 208          * @param ResourceLoaderContext $context Any context
 209          * @param string|null $variant Variant to get the URI for
 210          * @param string $format Format to get the URI for, 'original' or 'rasterized'
 211          * @return string
 212          */
 213         public function getDataUri( ResourceLoaderContext $context, $variant, $format ) {
 214                 $type = $this->getMimeType( $format );
 215                 $contents = $this->getImageData( $context, $variant, $format );
 216                 return CSSMin::encodeStringAsDataURI( $contents, $type );
 217         }
 218
 219         /**
 220          * Get actual image data for this image. This can be saved to a file or sent to the browser to
 221          * produce the converted image.
 222          *
 223          * Call getExtension() or getMimeType() with the same $format argument to learn what file type the
 224          * returned data uses.
 225          *
 226          * @param ResourceLoaderContext $context Image context, or any context if $variant and $format
 227          *     given.
 228          * @param string|null $variant Variant to get the data for. Optional; if given, overrides the data
 229          *     from $context.
 230          * @param string $format Format to get the data for, 'original' or 'rasterized'. Optional; if
 231          *     given, overrides the data from $context.
 232          * @return string|false Possibly binary image data, or false on failure
 233          * @throws MWException If the image file doesn't exist
 234          */
 235         public function getImageData( ResourceLoaderContext $context, $variant = false, $format = false ) {
 236                 if ( $variant === false ) {
 237                         $variant = $context->getVariant();
 238                 }
 239                 if ( $format === false ) {
 240                         $format = $context->getFormat();
 241                 }
 242
 243                 $path = $this->getPath( $context );
 244                 if ( !file_exists( $path ) ) {
 245                         throw new MWException( "File '$path' does not exist" );
 246                 }
 247
 248                 if ( $this->getExtension() !== 'svg' ) {
 249                         return file_get_contents( $path );
 250                 }
 251
 252                 if ( $variant && isset( $this->variants[$variant] ) ) {
 253                         $data = $this->variantize( $this->variants[$variant], $context );
 254                 } else {
 255                         $defaultColor = $this->defaultColor;
 256                         $data = $defaultColor ?
 257                                 $this->variantize( [ 'color' => $defaultColor ], $context ) :
 258                                 file_get_contents( $path );
 259                 }
 260
 261                 if ( $format === 'rasterized' ) {
 262                         $data = $this->rasterize( $data );
 263                         if ( !$data ) {
 264                                 wfDebugLog( 'ResourceLoaderImage', __METHOD__ . " failed to rasterize for $path" );
 265                         }
 266                 }
 267
 268                 return $data;
 269         }
 270
 271         /**
 272          * Send response headers (using the header() function) that are necessary to correctly serve the
 273          * image data for this image, as returned by getImageData().
 274          *
 275          * Note that the headers are independent of the language or image variant.
 276          *
 277          * @param ResourceLoaderContext $context Image context
 278          */
 279         public function sendResponseHeaders( ResourceLoaderContext $context ) {
 280                 $format = $context->getFormat();
 281                 $mime = $this->getMimeType( $format );
 282                 $filename = $this->getName() . '.' . $this->getExtension( $format );
 283
 284                 header( 'Content-Type: ' . $mime );
 285                 header( 'Content-Disposition: ' .
 286                         FileBackend::makeContentDisposition( 'inline', $filename ) );
 287         }
 288
 289         /**
 290          * Convert this image, which is assumed to be SVG, to given variant.
 291          *
 292          * @param array $variantConf Array with a 'color' key, its value will be used as fill color
 293          * @param ResourceLoaderContext $context Image context
 294          * @return string New SVG file data
 295          */
 296         protected function variantize( $variantConf, ResourceLoaderContext $context ) {
 297                 $dom = new DOMDocument;
 298                 $dom->loadXML( file_get_contents( $this->getPath( $context ) ) );
 299                 $root = $dom->documentElement;
 300                 $titleNode = null;
 301                 $wrapper = $dom->createElementNS( 'http://www.w3.org/2000/svg', 'g' );
 302                 // Reattach all direct children of the `<svg>` root node to the `<g>` wrapper
 303                 while ( $root->firstChild ) {
 304                         $node = $root->firstChild;
 305                         if ( !$titleNode && $node->nodeType === XML_ELEMENT_NODE && $node->tagName === 'title' ) {
 306                                 // Remember the first encountered `<title>` node
 307                                 $titleNode = $node;
 308                         }
 309                         $wrapper->appendChild( $node );
 310                 }
 311                 if ( $titleNode ) {
 312                         // Reattach the `<title>` node to the `<svg>` root node rather than the `<g>` wrapper
 313                         $root->appendChild( $titleNode );
 314                 }
 315                 $root->appendChild( $wrapper );
 316                 $wrapper->setAttribute( 'fill', $variantConf['color'] );
 317                 return $dom->saveXML();
 318         }
 319
 320         /**
 321          * Massage the SVG image data for converters which don't understand some path data syntax.
 322          *
 323          * This is necessary for rsvg and ImageMagick when compiled with rsvg support.
 324          * Upstream bug is https://bugzilla.gnome.org/show_bug.cgi?id=620923, fixed 2014-11-10, so
 325          * this will be needed for a while. (T76852)
 326          *
 327          * @param string $svg SVG image data
 328          * @return string Massaged SVG image data
 329          */
 330         protected function massageSvgPathdata( $svg ) {
 331                 $dom = new DOMDocument;
 332                 $dom->loadXML( $svg );
 333                 foreach ( $dom->getElementsByTagName( 'path' ) as $node ) {
 334                         $pathData = $node->getAttribute( 'd' );
 335                         // Make sure there is at least one space between numbers, and that leading zero is not omitted.
 336                         // rsvg has issues with syntax like "M-1-2" and "M.445.483" and especially "M-.445-.483".
 337                         $pathData = preg_replace( '/(-?)(\d*\.\d+|\d+)/', ' ${1}0$2 ', $pathData );
 338                         // Strip unnecessary leading zeroes for prettiness, not strictly necessary
 339                         $pathData = preg_replace( '/([ -])0(\d)/', '$1$2', $pathData );
 340                         $node->setAttribute( 'd', $pathData );
 341                 }
 342                 return $dom->saveXML();
 343         }
 344
 345         /**
 346          * Convert passed image data, which is assumed to be SVG, to PNG.
 347          *
 348          * @param string $svg SVG image data
 349          * @return string|bool PNG image data, or false on failure
 350          */
 351         protected function rasterize( $svg ) {
 352                 /**
 353                  * This code should be factored out to a separate method on SvgHandler, or perhaps a separate
 354                  * class, with a separate set of configuration settings.
 355                  *
 356                  * This is a distinct use case from regular SVG rasterization:
 357                  * * We can skip many sanity and security checks (as the images come from a trusted source,
 358                  *   rather than from the user).
 359                  * * We need to provide extra options to some converters to achieve acceptable quality for very
 360                  *   small images, which might cause performance issues in the general case.
 361                  * * We want to directly pass image data to the converter, rather than a file path.
 362                  *
 363                  * See https://phabricator.wikimedia.org/T76473#801446 for examples of what happens with the
 364                  * default settings.
 365                  *
 366                  * For now, we special-case rsvg (used in WMF production) and do a messy workaround for other
 367                  * converters.
 368                  */
 369
 370                 global $wgSVGConverter, $wgSVGConverterPath;
 371
 372                 $svg = $this->massageSvgPathdata( $svg );
 373
 374                 // Sometimes this might be 'rsvg-secure'. Long as it's rsvg.
 375                 if ( strpos( $wgSVGConverter, 'rsvg' ) === 0 ) {
 376                         $command = 'rsvg-convert';
 377                         if ( $wgSVGConverterPath ) {
 378                                 $command = Shell::escape( "$wgSVGConverterPath/" ) . $command;
 379                         }
 380
 381                         $process = proc_open(
 382                                 $command,
 383                                 [ 0 => [ 'pipe', 'r' ], 1 => [ 'pipe', 'w' ] ],
 384                                 $pipes
 385                         );
 386
 387                         if ( is_resource( $process ) ) {
 388                                 fwrite( $pipes[0], $svg );
 389                                 fclose( $pipes[0] );
 390                                 $png = stream_get_contents( $pipes[1] );
 391                                 fclose( $pipes[1] );
 392                                 proc_close( $process );
 393
 394                                 return $png ?: false;
 395                         }
 396                         return false;
 397
 398                 } else {
 399                         // Write input to and read output from a temporary file
 400                         $tempFilenameSvg = tempnam( wfTempDir(), 'ResourceLoaderImage' );
 401                         $tempFilenamePng = tempnam( wfTempDir(), 'ResourceLoaderImage' );
 402
 403                         file_put_contents( $tempFilenameSvg, $svg );
 404
 405                         $metadata = SVGMetadataExtractor::getMetadata( $tempFilenameSvg );
 406                         if ( !isset( $metadata['width'] ) || !isset( $metadata['height'] ) ) {
 407                                 unlink( $tempFilenameSvg );
 408                                 return false;
 409                         }
 410
 411                         $handler = new SvgHandler;
 412                         $res = $handler->rasterize(
 413                                 $tempFilenameSvg,
 414                                 $tempFilenamePng,
 415                                 $metadata['width'],
 416                                 $metadata['height']
 417                         );
 418                         unlink( $tempFilenameSvg );
 419
 420                         $png = null;
 421                         if ( $res === true ) {
 422                                 $png = file_get_contents( $tempFilenamePng );
 423                                 unlink( $tempFilenamePng );
 424                         }
 425
 426                         return $png ?: false;
 427                 }
 428         }
 429 }