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