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         /** @var string */
  44         private $name;
  45         /** @var string */
  46         private $module;
  47         /** @var string|array */
  48         private $descriptor;
  49         /** @var string */
  50         private $basePath;
  51         /** @var array */
  52         private $variants;
  53         /** @var string|null */
  54         private $defaultColor;
  55         /** @var string */
  56         private $extension;
  57
  58         /**
  59          * @param string $name Image name
  60          * @param string $module Module name
  61          * @param string|array $descriptor Path to image file, or array structure containing paths
  62          * @param string $basePath Directory to which paths in descriptor refer
  63          * @param array $variants
  64          * @param string|null $defaultColor of the base variant
  65          * @throws InvalidArgumentException
  66          */
  67         public function __construct( $name, $module, $descriptor, $basePath, $variants,
  68                 $defaultColor = null
  69         ) {
  70                 $this->name = $name;
  71                 $this->module = $module;
  72                 $this->descriptor = $descriptor;
  73                 $this->basePath = $basePath;
  74                 $this->variants = $variants;
  75                 $this->defaultColor = $defaultColor;
  76
  77                 // Expand shorthands:
  78                 // [ "en,de,fr" => "foo.svg" ]
  79                 // → [ "en" => "foo.svg", "de" => "foo.svg", "fr" => "foo.svg" ]
  80                 if ( is_array( $this->descriptor ) && isset( $this->descriptor['lang'] ) ) {
  81                         foreach ( array_keys( $this->descriptor['lang'] ) as $langList ) {
  82                                 if ( strpos( $langList, ',' ) !== false ) {
  83                                         $this->descriptor['lang'] += array_fill_keys(
  84                                                 explode( ',', $langList ),
  85                                                 $this->descriptor['lang'][$langList]
  86                                         );
  87                                         unset( $this->descriptor['lang'][$langList] );
  88                                 }
  89                         }
  90                 }
  91                 // Remove 'deprecated' key
  92                 if ( is_array( $this->descriptor ) ) {
  93                         unset( $this->descriptor['deprecated'] );
  94                 }
  95
  96                 // Ensure that all files have common extension.
  97                 $extensions = [];
  98                 $descriptor = (array)$this->descriptor;
  99                 array_walk_recursive( $descriptor, function ( $path ) use ( &$extensions ) {
 100                         $extensions[] = pathinfo( $path, PATHINFO_EXTENSION );
 101                 } );
 102                 $extensions = array_unique( $extensions );
 103                 if ( count( $extensions ) !== 1 ) {
 104                         throw new InvalidArgumentException(
 105                                 "File type for different image files of '$name' not the same in module '$module'"
 106                         );
 107                 }
 108                 $ext = $extensions[0];
 109                 if ( !isset( self::$fileTypes[$ext] ) ) {
 110                         throw new InvalidArgumentException(
 111                                 "Invalid file type for image files of '$name' (valid: svg, png, gif, jpg) in module '$module'"
 112                         );
 113                 }
 114                 $this->extension = $ext;
 115         }
 116
 117         /**
 118          * Get name of this image.
 119          *
 120          * @return string
 121          */
 122         public function getName() {
 123                 return $this->name;
 124         }
 125
 126         /**
 127          * Get name of the module this image belongs to.
 128          *
 129          * @return string
 130          */
 131         public function getModule() {
 132                 return $this->module;
 133         }
 134
 135         /**
 136          * Get the list of variants this image can be converted to.
 137          *
 138          * @return string[]
 139          */
 140         public function getVariants() {
 141                 return array_keys( $this->variants );
 142         }
 143
 144         /**
 145          * Get the path to image file for given context.
 146          *
 147          * @param ResourceLoaderContext $context Any context
 148          * @return string
 149          * @throws MWException If no matching path is found
 150          */
 151         public function getPath( ResourceLoaderContext $context ) {
 152                 $desc = $this->descriptor;
 153                 if ( is_string( $desc ) ) {
 154                         return $this->basePath . '/' . $desc;
 155                 }
 156                 if ( isset( $desc['lang'] ) ) {
 157                         $contextLang = $context->getLanguage();
 158                         if ( isset( $desc['lang'][$contextLang] ) ) {
 159                                 return $this->basePath . '/' . $desc['lang'][$contextLang];
 160                         }
 161                         $fallbacks = Language::getFallbacksFor( $contextLang, Language::STRICT_FALLBACKS );
 162                         foreach ( $fallbacks as $lang ) {
 163                                 if ( isset( $desc['lang'][$lang] ) ) {
 164                                         return $this->basePath . '/' . $desc['lang'][$lang];
 165                                 }
 166                         }
 167                 }
 168                 if ( isset( $desc[$context->getDirection()] ) ) {
 169                         return $this->basePath . '/' . $desc[$context->getDirection()];
 170                 }
 171                 if ( isset( $desc['default'] ) ) {
 172                         return $this->basePath . '/' . $desc['default'];
 173                 } else {
 174                         throw new MWException( 'No matching path found' );
 175                 }
 176         }
 177
 178         /**
 179          * Get the extension of the image.
 180          *
 181          * @param string $format Format to get the extension for, 'original' or 'rasterized'
 182          * @return string Extension without leading dot, e.g. 'png'
 183          */
 184         public function getExtension( $format = 'original' ) {
 185                 if ( $format === 'rasterized' && $this->extension === 'svg' ) {
 186                         return 'png';
 187                 }
 188                 return $this->extension;
 189         }
 190
 191         /**
 192          * Get the MIME type of the image.
 193          *
 194          * @param string $format Format to get the MIME type for, 'original' or 'rasterized'
 195          * @return string
 196          */
 197         public function getMimeType( $format = 'original' ) {
 198                 $ext = $this->getExtension( $format );
 199                 return self::$fileTypes[$ext];
 200         }
 201
 202         /**
 203          * Get the load.php URL that will produce this image.
 204          *
 205          * @param ResourceLoaderContext $context Any context
 206          * @param string $script URL to load.php
 207          * @param string|null $variant Variant to get the URL for
 208          * @param string $format Format to get the URL for, 'original' or 'rasterized'
 209          * @return string
 210          */
 211         public function getUrl( ResourceLoaderContext $context, $script, $variant, $format ) {
 212                 $query = [
 213                         'modules' => $this->getModule(),
 214                         'image' => $this->getName(),
 215                         'variant' => $variant,
 216                         'format' => $format,
 217                 ];
 218                 if ( $this->varyOnLanguage() ) {
 219                         $query['lang'] = $context->getLanguage();
 220                 }
 221                 // The following parameters are at the end to keep the original order of the parameters.
 222                 $query['skin'] = $context->getSkin();
 223                 $query['version'] = $context->getVersion();
 224
 225                 return wfAppendQuery( $script, $query );
 226         }
 227
 228         /**
 229          * Get the data: URI that will produce this image.
 230          *
 231          * @param ResourceLoaderContext $context Any context
 232          * @param string|null $variant Variant to get the URI for
 233          * @param string $format Format to get the URI for, 'original' or 'rasterized'
 234          * @return string
 235          */
 236         public function getDataUri( ResourceLoaderContext $context, $variant, $format ) {
 237                 $type = $this->getMimeType( $format );
 238                 $contents = $this->getImageData( $context, $variant, $format );
 239                 return CSSMin::encodeStringAsDataURI( $contents, $type );
 240         }
 241
 242         /**
 243          * Get actual image data for this image. This can be saved to a file or sent to the browser to
 244          * produce the converted image.
 245          *
 246          * Call getExtension() or getMimeType() with the same $format argument to learn what file type the
 247          * returned data uses.
 248          *
 249          * @param ResourceLoaderContext $context Image context, or any context if $variant and $format
 250          *     given.
 251          * @param string|null $variant Variant to get the data for. Optional; if given, overrides the data
 252          *     from $context.
 253          * @param string $format Format to get the data for, 'original' or 'rasterized'. Optional; if
 254          *     given, overrides the data from $context.
 255          * @return string|false Possibly binary image data, or false on failure
 256          * @throws MWException If the image file doesn't exist
 257          */
 258         public function getImageData( ResourceLoaderContext $context, $variant = false, $format = false ) {
 259                 if ( $variant === false ) {
 260                         $variant = $context->getVariant();
 261                 }
 262                 if ( $format === false ) {
 263                         $format = $context->getFormat();
 264                 }
 265
 266                 $path = $this->getPath( $context );
 267                 if ( !file_exists( $path ) ) {
 268                         throw new MWException( "File '$path' does not exist" );
 269                 }
 270
 271                 if ( $this->getExtension() !== 'svg' ) {
 272                         return file_get_contents( $path );
 273                 }
 274
 275                 if ( $variant && isset( $this->variants[$variant] ) ) {
 276                         $data = $this->variantize( $this->variants[$variant], $context );
 277                 } else {
 278                         $defaultColor = $this->defaultColor;
 279                         $data = $defaultColor ?
 280                                 $this->variantize( [ 'color' => $defaultColor ], $context ) :
 281                                 file_get_contents( $path );
 282                 }
 283
 284                 if ( $format === 'rasterized' ) {
 285                         $data = $this->rasterize( $data );
 286                         if ( !$data ) {
 287                                 wfDebugLog( 'ResourceLoaderImage', __METHOD__ . " failed to rasterize for $path" );
 288                         }
 289                 }
 290
 291                 return $data;
 292         }
 293
 294         /**
 295          * Send response headers (using the header() function) that are necessary to correctly serve the
 296          * image data for this image, as returned by getImageData().
 297          *
 298          * Note that the headers are independent of the language or image variant.
 299          *
 300          * @param ResourceLoaderContext $context Image context
 301          */
 302         public function sendResponseHeaders( ResourceLoaderContext $context ) {
 303                 $format = $context->getFormat();
 304                 $mime = $this->getMimeType( $format );
 305                 $filename = $this->getName() . '.' . $this->getExtension( $format );
 306
 307                 header( 'Content-Type: ' . $mime );
 308                 header( 'Content-Disposition: ' .
 309                         FileBackend::makeContentDisposition( 'inline', $filename ) );
 310         }
 311
 312         /**
 313          * Convert this image, which is assumed to be SVG, to given variant.
 314          *
 315          * @param array $variantConf Array with a 'color' key, its value will be used as fill color
 316          * @param ResourceLoaderContext $context Image context
 317          * @return string New SVG file data
 318          */
 319         protected function variantize( $variantConf, ResourceLoaderContext $context ) {
 320                 $dom = new DOMDocument;
 321                 $dom->loadXML( file_get_contents( $this->getPath( $context ) ) );
 322                 $root = $dom->documentElement;
 323                 $titleNode = null;
 324                 $wrapper = $dom->createElementNS( 'http://www.w3.org/2000/svg', 'g' );
 325                 // Reattach all direct children of the `<svg>` root node to the `<g>` wrapper
 326                 while ( $root->firstChild ) {
 327                         $node = $root->firstChild;
 328                         if ( !$titleNode && $node->nodeType === XML_ELEMENT_NODE && $node->tagName === 'title' ) {
 329                                 // Remember the first encountered `<title>` node
 330                                 $titleNode = $node;
 331                         }
 332                         $wrapper->appendChild( $node );
 333                 }
 334                 if ( $titleNode ) {
 335                         // Reattach the `<title>` node to the `<svg>` root node rather than the `<g>` wrapper
 336                         $root->appendChild( $titleNode );
 337                 }
 338                 $root->appendChild( $wrapper );
 339                 $wrapper->setAttribute( 'fill', $variantConf['color'] );
 340                 return $dom->saveXML();
 341         }
 342
 343         /**
 344          * Massage the SVG image data for converters which don't understand some path data syntax.
 345          *
 346          * This is necessary for rsvg and ImageMagick when compiled with rsvg support.
 347          * Upstream bug is https://bugzilla.gnome.org/show_bug.cgi?id=620923, fixed 2014-11-10, so
 348          * this will be needed for a while. (T76852)
 349          *
 350          * @param string $svg SVG image data
 351          * @return string Massaged SVG image data
 352          */
 353         protected function massageSvgPathdata( $svg ) {
 354                 $dom = new DOMDocument;
 355                 $dom->loadXML( $svg );
 356                 foreach ( $dom->getElementsByTagName( 'path' ) as $node ) {
 357                         $pathData = $node->getAttribute( 'd' );
 358                         // Make sure there is at least one space between numbers, and that leading zero is not omitted.
 359                         // rsvg has issues with syntax like "M-1-2" and "M.445.483" and especially "M-.445-.483".
 360                         $pathData = preg_replace( '/(-?)(\d*\.\d+|\d+)/', ' ${1}0$2 ', $pathData );
 361                         // Strip unnecessary leading zeroes for prettiness, not strictly necessary
 362                         $pathData = preg_replace( '/([ -])0(\d)/', '$1$2', $pathData );
 363                         $node->setAttribute( 'd', $pathData );
 364                 }
 365                 return $dom->saveXML();
 366         }
 367
 368         /**
 369          * Convert passed image data, which is assumed to be SVG, to PNG.
 370          *
 371          * @param string $svg SVG image data
 372          * @return string|bool PNG image data, or false on failure
 373          */
 374         protected function rasterize( $svg ) {
 375                 /**
 376                  * This code should be factored out to a separate method on SvgHandler, or perhaps a separate
 377                  * class, with a separate set of configuration settings.
 378                  *
 379                  * This is a distinct use case from regular SVG rasterization:
 380                  * * We can skip many sanity and security checks (as the images come from a trusted source,
 381                  *   rather than from the user).
 382                  * * We need to provide extra options to some converters to achieve acceptable quality for very
 383                  *   small images, which might cause performance issues in the general case.
 384                  * * We want to directly pass image data to the converter, rather than a file path.
 385                  *
 386                  * See https://phabricator.wikimedia.org/T76473#801446 for examples of what happens with the
 387                  * default settings.
 388                  *
 389                  * For now, we special-case rsvg (used in WMF production) and do a messy workaround for other
 390                  * converters.
 391                  */
 392
 393                 global $wgSVGConverter, $wgSVGConverterPath;
 394
 395                 $svg = $this->massageSvgPathdata( $svg );
 396
 397                 // Sometimes this might be 'rsvg-secure'. Long as it's rsvg.
 398                 if ( strpos( $wgSVGConverter, 'rsvg' ) === 0 ) {
 399                         $command = 'rsvg-convert';
 400                         if ( $wgSVGConverterPath ) {
 401                                 $command = Shell::escape( "$wgSVGConverterPath/" ) . $command;
 402                         }
 403
 404                         $process = proc_open(
 405                                 $command,
 406                                 [ 0 => [ 'pipe', 'r' ], 1 => [ 'pipe', 'w' ] ],
 407                                 $pipes
 408                         );
 409
 410                         if ( is_resource( $process ) ) {
 411                                 fwrite( $pipes[0], $svg );
 412                                 fclose( $pipes[0] );
 413                                 $png = stream_get_contents( $pipes[1] );
 414                                 fclose( $pipes[1] );
 415                                 proc_close( $process );
 416
 417                                 return $png ?: false;
 418                         }
 419                         return false;
 420
 421                 } else {
 422                         // Write input to and read output from a temporary file
 423                         $tempFilenameSvg = tempnam( wfTempDir(), 'ResourceLoaderImage' );
 424                         $tempFilenamePng = tempnam( wfTempDir(), 'ResourceLoaderImage' );
 425
 426                         file_put_contents( $tempFilenameSvg, $svg );
 427
 428                         $metadata = SVGMetadataExtractor::getMetadata( $tempFilenameSvg );
 429                         if ( !isset( $metadata['width'] ) || !isset( $metadata['height'] ) ) {
 430                                 unlink( $tempFilenameSvg );
 431                                 return false;
 432                         }
 433
 434                         $handler = new SvgHandler;
 435                         $res = $handler->rasterize(
 436                                 $tempFilenameSvg,
 437                                 $tempFilenamePng,
 438                                 $metadata['width'],
 439                                 $metadata['height']
 440                         );
 441                         unlink( $tempFilenameSvg );
 442
 443                         $png = null;
 444                         if ( $res === true ) {
 445                                 $png = file_get_contents( $tempFilenamePng );
 446                                 unlink( $tempFilenamePng );
 447                         }
 448
 449                         return $png ?: false;
 450                 }
 451         }
 452
 453         /**
 454          * Check if the image depends on the language.
 455          *
 456          * @return bool
 457          */
 458         private function varyOnLanguage() {
 459                 return is_array( $this->descriptor ) && (
 460                         isset( $this->descriptor['ltr'] ) ||
 461                         isset( $this->descriptor['rtl'] ) ||
 462                         isset( $this->descriptor['lang'] ) );
 463         }
 464 }