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                         'lang' => $context->getLanguage(),
 218                         'skin' => $context->getSkin(),
 219                         'version' => $context->getVersion(),
 220                 ];
 221
 222                 return wfAppendQuery( $script, $query );
 223         }
 224
 225         /**
 226          * Get the data: URI that will produce this image.
 227          *
 228          * @param ResourceLoaderContext $context Any context
 229          * @param string|null $variant Variant to get the URI for
 230          * @param string $format Format to get the URI for, 'original' or 'rasterized'
 231          * @return string
 232          */
 233         public function getDataUri( ResourceLoaderContext $context, $variant, $format ) {
 234                 $type = $this->getMimeType( $format );
 235                 $contents = $this->getImageData( $context, $variant, $format );
 236                 return CSSMin::encodeStringAsDataURI( $contents, $type );
 237         }
 238
 239         /**
 240          * Get actual image data for this image. This can be saved to a file or sent to the browser to
 241          * produce the converted image.
 242          *
 243          * Call getExtension() or getMimeType() with the same $format argument to learn what file type the
 244          * returned data uses.
 245          *
 246          * @param ResourceLoaderContext $context Image context, or any context if $variant and $format
 247          *     given.
 248          * @param string|null $variant Variant to get the data for. Optional; if given, overrides the data
 249          *     from $context.
 250          * @param string $format Format to get the data for, 'original' or 'rasterized'. Optional; if
 251          *     given, overrides the data from $context.
 252          * @return string|false Possibly binary image data, or false on failure
 253          * @throws MWException If the image file doesn't exist
 254          */
 255         public function getImageData( ResourceLoaderContext $context, $variant = false, $format = false ) {
 256                 if ( $variant === false ) {
 257                         $variant = $context->getVariant();
 258                 }
 259                 if ( $format === false ) {
 260                         $format = $context->getFormat();
 261                 }
 262
 263                 $path = $this->getPath( $context );
 264                 if ( !file_exists( $path ) ) {
 265                         throw new MWException( "File '$path' does not exist" );
 266                 }
 267
 268                 if ( $this->getExtension() !== 'svg' ) {
 269                         return file_get_contents( $path );
 270                 }
 271
 272                 if ( $variant && isset( $this->variants[$variant] ) ) {
 273                         $data = $this->variantize( $this->variants[$variant], $context );
 274                 } else {
 275                         $defaultColor = $this->defaultColor;
 276                         $data = $defaultColor ?
 277                                 $this->variantize( [ 'color' => $defaultColor ], $context ) :
 278                                 file_get_contents( $path );
 279                 }
 280
 281                 if ( $format === 'rasterized' ) {
 282                         $data = $this->rasterize( $data );
 283                         if ( !$data ) {
 284                                 wfDebugLog( 'ResourceLoaderImage', __METHOD__ . " failed to rasterize for $path" );
 285                         }
 286                 }
 287
 288                 return $data;
 289         }
 290
 291         /**
 292          * Send response headers (using the header() function) that are necessary to correctly serve the
 293          * image data for this image, as returned by getImageData().
 294          *
 295          * Note that the headers are independent of the language or image variant.
 296          *
 297          * @param ResourceLoaderContext $context Image context
 298          */
 299         public function sendResponseHeaders( ResourceLoaderContext $context ) {
 300                 $format = $context->getFormat();
 301                 $mime = $this->getMimeType( $format );
 302                 $filename = $this->getName() . '.' . $this->getExtension( $format );
 303
 304                 header( 'Content-Type: ' . $mime );
 305                 header( 'Content-Disposition: ' .
 306                         FileBackend::makeContentDisposition( 'inline', $filename ) );
 307         }
 308
 309         /**
 310          * Convert this image, which is assumed to be SVG, to given variant.
 311          *
 312          * @param array $variantConf Array with a 'color' key, its value will be used as fill color
 313          * @param ResourceLoaderContext $context Image context
 314          * @return string New SVG file data
 315          */
 316         protected function variantize( $variantConf, ResourceLoaderContext $context ) {
 317                 $dom = new DOMDocument;
 318                 $dom->loadXML( file_get_contents( $this->getPath( $context ) ) );
 319                 $root = $dom->documentElement;
 320                 $titleNode = null;
 321                 $wrapper = $dom->createElementNS( 'http://www.w3.org/2000/svg', 'g' );
 322                 // Reattach all direct children of the `<svg>` root node to the `<g>` wrapper
 323                 while ( $root->firstChild ) {
 324                         $node = $root->firstChild;
 325                         if ( !$titleNode && $node->nodeType === XML_ELEMENT_NODE && $node->tagName === 'title' ) {
 326                                 // Remember the first encountered `<title>` node
 327                                 $titleNode = $node;
 328                         }
 329                         $wrapper->appendChild( $node );
 330                 }
 331                 if ( $titleNode ) {
 332                         // Reattach the `<title>` node to the `<svg>` root node rather than the `<g>` wrapper
 333                         $root->appendChild( $titleNode );
 334                 }
 335                 $root->appendChild( $wrapper );
 336                 $wrapper->setAttribute( 'fill', $variantConf['color'] );
 337                 return $dom->saveXML();
 338         }
 339
 340         /**
 341          * Massage the SVG image data for converters which don't understand some path data syntax.
 342          *
 343          * This is necessary for rsvg and ImageMagick when compiled with rsvg support.
 344          * Upstream bug is https://bugzilla.gnome.org/show_bug.cgi?id=620923, fixed 2014-11-10, so
 345          * this will be needed for a while. (T76852)
 346          *
 347          * @param string $svg SVG image data
 348          * @return string Massaged SVG image data
 349          */
 350         protected function massageSvgPathdata( $svg ) {
 351                 $dom = new DOMDocument;
 352                 $dom->loadXML( $svg );
 353                 foreach ( $dom->getElementsByTagName( 'path' ) as $node ) {
 354                         $pathData = $node->getAttribute( 'd' );
 355                         // Make sure there is at least one space between numbers, and that leading zero is not omitted.
 356                         // rsvg has issues with syntax like "M-1-2" and "M.445.483" and especially "M-.445-.483".
 357                         $pathData = preg_replace( '/(-?)(\d*\.\d+|\d+)/', ' ${1}0$2 ', $pathData );
 358                         // Strip unnecessary leading zeroes for prettiness, not strictly necessary
 359                         $pathData = preg_replace( '/([ -])0(\d)/', '$1$2', $pathData );
 360                         $node->setAttribute( 'd', $pathData );
 361                 }
 362                 return $dom->saveXML();
 363         }
 364
 365         /**
 366          * Convert passed image data, which is assumed to be SVG, to PNG.
 367          *
 368          * @param string $svg SVG image data
 369          * @return string|bool PNG image data, or false on failure
 370          */
 371         protected function rasterize( $svg ) {
 372                 /**
 373                  * This code should be factored out to a separate method on SvgHandler, or perhaps a separate
 374                  * class, with a separate set of configuration settings.
 375                  *
 376                  * This is a distinct use case from regular SVG rasterization:
 377                  * * We can skip many sanity and security checks (as the images come from a trusted source,
 378                  *   rather than from the user).
 379                  * * We need to provide extra options to some converters to achieve acceptable quality for very
 380                  *   small images, which might cause performance issues in the general case.
 381                  * * We want to directly pass image data to the converter, rather than a file path.
 382                  *
 383                  * See https://phabricator.wikimedia.org/T76473#801446 for examples of what happens with the
 384                  * default settings.
 385                  *
 386                  * For now, we special-case rsvg (used in WMF production) and do a messy workaround for other
 387                  * converters.
 388                  */
 389
 390                 global $wgSVGConverter, $wgSVGConverterPath;
 391
 392                 $svg = $this->massageSvgPathdata( $svg );
 393
 394                 // Sometimes this might be 'rsvg-secure'. Long as it's rsvg.
 395                 if ( strpos( $wgSVGConverter, 'rsvg' ) === 0 ) {
 396                         $command = 'rsvg-convert';
 397                         if ( $wgSVGConverterPath ) {
 398                                 $command = Shell::escape( "$wgSVGConverterPath/" ) . $command;
 399                         }
 400
 401                         $process = proc_open(
 402                                 $command,
 403                                 [ 0 => [ 'pipe', 'r' ], 1 => [ 'pipe', 'w' ] ],
 404                                 $pipes
 405                         );
 406
 407                         if ( is_resource( $process ) ) {
 408                                 fwrite( $pipes[0], $svg );
 409                                 fclose( $pipes[0] );
 410                                 $png = stream_get_contents( $pipes[1] );
 411                                 fclose( $pipes[1] );
 412                                 proc_close( $process );
 413
 414                                 return $png ?: false;
 415                         }
 416                         return false;
 417
 418                 } else {
 419                         // Write input to and read output from a temporary file
 420                         $tempFilenameSvg = tempnam( wfTempDir(), 'ResourceLoaderImage' );
 421                         $tempFilenamePng = tempnam( wfTempDir(), 'ResourceLoaderImage' );
 422
 423                         file_put_contents( $tempFilenameSvg, $svg );
 424
 425                         $metadata = SVGMetadataExtractor::getMetadata( $tempFilenameSvg );
 426                         if ( !isset( $metadata['width'] ) || !isset( $metadata['height'] ) ) {
 427                                 unlink( $tempFilenameSvg );
 428                                 return false;
 429                         }
 430
 431                         $handler = new SvgHandler;
 432                         $res = $handler->rasterize(
 433                                 $tempFilenameSvg,
 434                                 $tempFilenamePng,
 435                                 $metadata['width'],
 436                                 $metadata['height']
 437                         );
 438                         unlink( $tempFilenameSvg );
 439
 440                         $png = null;
 441                         if ( $res === true ) {
 442                                 $png = file_get_contents( $tempFilenamePng );
 443                                 unlink( $tempFilenamePng );
 444                         }
 445
 446                         return $png ?: false;
 447                 }
 448         }
 449 }