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