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          */
 150         public function getPath( ResourceLoaderContext $context ) {
 151                 $desc = $this->descriptor;
 152                 if ( is_string( $desc ) ) {
 153                         return $this->basePath . '/' . $desc;
 154                 }
 155                 if ( isset( $desc['lang'] ) ) {
 156                         $contextLang = $context->getLanguage();
 157                         if ( isset( $desc['lang'][$contextLang] ) ) {
 158                                 return $this->basePath . '/' . $desc['lang'][$contextLang];
 159                         }
 160                         $fallbacks = Language::getFallbacksFor( $contextLang, Language::STRICT_FALLBACKS );
 161                         foreach ( $fallbacks as $lang ) {
 162                                 if ( isset( $desc['lang'][$lang] ) ) {
 163                                         return $this->basePath . '/' . $desc['lang'][$lang];
 164                                 }
 165                         }
 166                 }
 167                 if ( isset( $desc[$context->getDirection()] ) ) {
 168                         return $this->basePath . '/' . $desc[$context->getDirection()];
 169                 }
 170                 return $this->basePath . '/' . $desc['default'];
 171         }
 172
 173         /**
 174          * Get the extension of the image.
 175          *
 176          * @param string $format Format to get the extension for, 'original' or 'rasterized'
 177          * @return string Extension without leading dot, e.g. 'png'
 178          */
 179         public function getExtension( $format = 'original' ) {
 180                 if ( $format === 'rasterized' && $this->extension === 'svg' ) {
 181                         return 'png';
 182                 }
 183                 return $this->extension;
 184         }
 185
 186         /**
 187          * Get the MIME type of the image.
 188          *
 189          * @param string $format Format to get the MIME type for, 'original' or 'rasterized'
 190          * @return string
 191          */
 192         public function getMimeType( $format = 'original' ) {
 193                 $ext = $this->getExtension( $format );
 194                 return self::$fileTypes[$ext];
 195         }
 196
 197         /**
 198          * Get the load.php URL that will produce this image.
 199          *
 200          * @param ResourceLoaderContext $context Any context
 201          * @param string $script URL to load.php
 202          * @param string|null $variant Variant to get the URL for
 203          * @param string $format Format to get the URL for, 'original' or 'rasterized'
 204          * @return string
 205          */
 206         public function getUrl( ResourceLoaderContext $context, $script, $variant, $format ) {
 207                 $query = [
 208                         'modules' => $this->getModule(),
 209                         'image' => $this->getName(),
 210                         'variant' => $variant,
 211                         'format' => $format,
 212                         'lang' => $context->getLanguage(),
 213                         'skin' => $context->getSkin(),
 214                         'version' => $context->getVersion(),
 215                 ];
 216
 217                 return wfAppendQuery( $script, $query );
 218         }
 219
 220         /**
 221          * Get the data: URI that will produce this image.
 222          *
 223          * @param ResourceLoaderContext $context Any context
 224          * @param string|null $variant Variant to get the URI for
 225          * @param string $format Format to get the URI for, 'original' or 'rasterized'
 226          * @return string
 227          */
 228         public function getDataUri( ResourceLoaderContext $context, $variant, $format ) {
 229                 $type = $this->getMimeType( $format );
 230                 $contents = $this->getImageData( $context, $variant, $format );
 231                 return CSSMin::encodeStringAsDataURI( $contents, $type );
 232         }
 233
 234         /**
 235          * Get actual image data for this image. This can be saved to a file or sent to the browser to
 236          * produce the converted image.
 237          *
 238          * Call getExtension() or getMimeType() with the same $format argument to learn what file type the
 239          * returned data uses.
 240          *
 241          * @param ResourceLoaderContext $context Image context, or any context if $variant and $format
 242          *     given.
 243          * @param string|null $variant Variant to get the data for. Optional; if given, overrides the data
 244          *     from $context.
 245          * @param string $format Format to get the data for, 'original' or 'rasterized'. Optional; if
 246          *     given, overrides the data from $context.
 247          * @return string|false Possibly binary image data, or false on failure
 248          * @throws MWException If the image file doesn't exist
 249          */
 250         public function getImageData( ResourceLoaderContext $context, $variant = false, $format = false ) {
 251                 if ( $variant === false ) {
 252                         $variant = $context->getVariant();
 253                 }
 254                 if ( $format === false ) {
 255                         $format = $context->getFormat();
 256                 }
 257
 258                 $path = $this->getPath( $context );
 259                 if ( !file_exists( $path ) ) {
 260                         throw new MWException( "File '$path' does not exist" );
 261                 }
 262
 263                 if ( $this->getExtension() !== 'svg' ) {
 264                         return file_get_contents( $path );
 265                 }
 266
 267                 if ( $variant && isset( $this->variants[$variant] ) ) {
 268                         $data = $this->variantize( $this->variants[$variant], $context );
 269                 } else {
 270                         $defaultColor = $this->defaultColor;
 271                         $data = $defaultColor ?
 272                                 $this->variantize( [ 'color' => $defaultColor ], $context ) :
 273                                 file_get_contents( $path );
 274                 }
 275
 276                 if ( $format === 'rasterized' ) {
 277                         $data = $this->rasterize( $data );
 278                         if ( !$data ) {
 279                                 wfDebugLog( 'ResourceLoaderImage', __METHOD__ . " failed to rasterize for $path" );
 280                         }
 281                 }
 282
 283                 return $data;
 284         }
 285
 286         /**
 287          * Send response headers (using the header() function) that are necessary to correctly serve the
 288          * image data for this image, as returned by getImageData().
 289          *
 290          * Note that the headers are independent of the language or image variant.
 291          *
 292          * @param ResourceLoaderContext $context Image context
 293          */
 294         public function sendResponseHeaders( ResourceLoaderContext $context ) {
 295                 $format = $context->getFormat();
 296                 $mime = $this->getMimeType( $format );
 297                 $filename = $this->getName() . '.' . $this->getExtension( $format );
 298
 299                 header( 'Content-Type: ' . $mime );
 300                 header( 'Content-Disposition: ' .
 301                         FileBackend::makeContentDisposition( 'inline', $filename ) );
 302         }
 303
 304         /**
 305          * Convert this image, which is assumed to be SVG, to given variant.
 306          *
 307          * @param array $variantConf Array with a 'color' key, its value will be used as fill color
 308          * @param ResourceLoaderContext $context Image context
 309          * @return string New SVG file data
 310          */
 311         protected function variantize( $variantConf, ResourceLoaderContext $context ) {
 312                 $dom = new DOMDocument;
 313                 $dom->loadXML( file_get_contents( $this->getPath( $context ) ) );
 314                 $root = $dom->documentElement;
 315                 $titleNode = null;
 316                 $wrapper = $dom->createElementNS( 'http://www.w3.org/2000/svg', 'g' );
 317                 // Reattach all direct children of the `<svg>` root node to the `<g>` wrapper
 318                 while ( $root->firstChild ) {
 319                         $node = $root->firstChild;
 320                         if ( !$titleNode && $node->nodeType === XML_ELEMENT_NODE && $node->tagName === 'title' ) {
 321                                 // Remember the first encountered `<title>` node
 322                                 $titleNode = $node;
 323                         }
 324                         $wrapper->appendChild( $node );
 325                 }
 326                 if ( $titleNode ) {
 327                         // Reattach the `<title>` node to the `<svg>` root node rather than the `<g>` wrapper
 328                         $root->appendChild( $titleNode );
 329                 }
 330                 $root->appendChild( $wrapper );
 331                 $wrapper->setAttribute( 'fill', $variantConf['color'] );
 332                 return $dom->saveXML();
 333         }
 334
 335         /**
 336          * Massage the SVG image data for converters which don't understand some path data syntax.
 337          *
 338          * This is necessary for rsvg and ImageMagick when compiled with rsvg support.
 339          * Upstream bug is https://bugzilla.gnome.org/show_bug.cgi?id=620923, fixed 2014-11-10, so
 340          * this will be needed for a while. (T76852)
 341          *
 342          * @param string $svg SVG image data
 343          * @return string Massaged SVG image data
 344          */
 345         protected function massageSvgPathdata( $svg ) {
 346                 $dom = new DOMDocument;
 347                 $dom->loadXML( $svg );
 348                 foreach ( $dom->getElementsByTagName( 'path' ) as $node ) {
 349                         $pathData = $node->getAttribute( 'd' );
 350                         // Make sure there is at least one space between numbers, and that leading zero is not omitted.
 351                         // rsvg has issues with syntax like "M-1-2" and "M.445.483" and especially "M-.445-.483".
 352                         $pathData = preg_replace( '/(-?)(\d*\.\d+|\d+)/', ' ${1}0$2 ', $pathData );
 353                         // Strip unnecessary leading zeroes for prettiness, not strictly necessary
 354                         $pathData = preg_replace( '/([ -])0(\d)/', '$1$2', $pathData );
 355                         $node->setAttribute( 'd', $pathData );
 356                 }
 357                 return $dom->saveXML();
 358         }
 359
 360         /**
 361          * Convert passed image data, which is assumed to be SVG, to PNG.
 362          *
 363          * @param string $svg SVG image data
 364          * @return string|bool PNG image data, or false on failure
 365          */
 366         protected function rasterize( $svg ) {
 367                 /**
 368                  * This code should be factored out to a separate method on SvgHandler, or perhaps a separate
 369                  * class, with a separate set of configuration settings.
 370                  *
 371                  * This is a distinct use case from regular SVG rasterization:
 372                  * * We can skip many sanity and security checks (as the images come from a trusted source,
 373                  *   rather than from the user).
 374                  * * We need to provide extra options to some converters to achieve acceptable quality for very
 375                  *   small images, which might cause performance issues in the general case.
 376                  * * We want to directly pass image data to the converter, rather than a file path.
 377                  *
 378                  * See https://phabricator.wikimedia.org/T76473#801446 for examples of what happens with the
 379                  * default settings.
 380                  *
 381                  * For now, we special-case rsvg (used in WMF production) and do a messy workaround for other
 382                  * converters.
 383                  */
 384
 385                 global $wgSVGConverter, $wgSVGConverterPath;
 386
 387                 $svg = $this->massageSvgPathdata( $svg );
 388
 389                 // Sometimes this might be 'rsvg-secure'. Long as it's rsvg.
 390                 if ( strpos( $wgSVGConverter, 'rsvg' ) === 0 ) {
 391                         $command = 'rsvg-convert';
 392                         if ( $wgSVGConverterPath ) {
 393                                 $command = Shell::escape( "$wgSVGConverterPath/" ) . $command;
 394                         }
 395
 396                         $process = proc_open(
 397                                 $command,
 398                                 [ 0 => [ 'pipe', 'r' ], 1 => [ 'pipe', 'w' ] ],
 399                                 $pipes
 400                         );
 401
 402                         if ( is_resource( $process ) ) {
 403                                 fwrite( $pipes[0], $svg );
 404                                 fclose( $pipes[0] );
 405                                 $png = stream_get_contents( $pipes[1] );
 406                                 fclose( $pipes[1] );
 407                                 proc_close( $process );
 408
 409                                 return $png ?: false;
 410                         }
 411                         return false;
 412
 413                 } else {
 414                         // Write input to and read output from a temporary file
 415                         $tempFilenameSvg = tempnam( wfTempDir(), 'ResourceLoaderImage' );
 416                         $tempFilenamePng = tempnam( wfTempDir(), 'ResourceLoaderImage' );
 417
 418                         file_put_contents( $tempFilenameSvg, $svg );
 419
 420                         $metadata = SVGMetadataExtractor::getMetadata( $tempFilenameSvg );
 421                         if ( !isset( $metadata['width'] ) || !isset( $metadata['height'] ) ) {
 422                                 unlink( $tempFilenameSvg );
 423                                 return false;
 424                         }
 425
 426                         $handler = new SvgHandler;
 427                         $res = $handler->rasterize(
 428                                 $tempFilenameSvg,
 429                                 $tempFilenamePng,
 430                                 $metadata['width'],
 431                                 $metadata['height']
 432                         );
 433                         unlink( $tempFilenameSvg );
 434
 435                         $png = null;
 436                         if ( $res === true ) {
 437                                 $png = file_get_contents( $tempFilenamePng );
 438                                 unlink( $tempFilenamePng );
 439                         }
 440
 441                         return $png ?: false;
 442                 }
 443         }
 444 }