includes/ResourceLoader/Image.php
<?php
/**
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
* http://www.gnu.org/copyleft/gpl.html
*
* @file
*/
namespace MediaWiki\ResourceLoader;
use DOMDocument;
use InvalidArgumentException;
use InvalidSVGException;
use MediaWiki\Languages\LanguageFallback;
use MediaWiki\MainConfigNames;
use MediaWiki\MediaWikiServices;
use MediaWiki\Shell\Shell;
use RuntimeException;
use SvgHandler;
use SVGReader;
use Wikimedia\FileBackend\FileBackend;
use Wikimedia\Minify\CSSMin;
/**
* Class encapsulating an image used in an ImageModule.
*
* @ingroup ResourceLoader
* @since 1.25
*/
class Image {
/**
* Map of allowed file extensions to their MIME types.
* @var array
*/
private const FILE_TYPES = [
'svg' => 'image/svg+xml',
'png' => 'image/png',
'gif' => 'image/gif',
'jpg' => 'image/jpg',
];
/** @var string */
private $name;
/** @var string */
private $module;
/** @var string|array */
private $descriptor;
/** @var string */
private $basePath;
/** @var array */
private $variants;
/** @var string|null */
private $defaultColor;
/** @var string */
private $extension;
/**
* @param string $name Self-name of the image as known to ImageModule.
* @param string $module Self-name of the module containing this image.
* Used to find the image in the registry e.g. through a load.php url.
* @param string|array $descriptor Path to image file, or array structure containing paths
* @param string $basePath Directory to which paths in descriptor refer
* @param array $variants
* @param string|null $defaultColor of the base variant
*/
public function __construct( $name, $module, $descriptor, $basePath, array $variants,
$defaultColor = null
) {
$this->name = $name;
$this->module = $module;
$this->descriptor = $descriptor;
$this->basePath = $basePath;
$this->variants = $variants;
$this->defaultColor = $defaultColor;
// Expand shorthands:
// [ "en,de,fr" => "foo.svg" ]
// → [ "en" => "foo.svg", "de" => "foo.svg", "fr" => "foo.svg" ]
if ( is_array( $this->descriptor ) && isset( $this->descriptor['lang'] ) ) {
foreach ( $this->descriptor['lang'] as $langList => $_ ) {
if ( strpos( $langList, ',' ) !== false ) {
$this->descriptor['lang'] += array_fill_keys(
explode( ',', $langList ),
$this->descriptor['lang'][$langList]
);
unset( $this->descriptor['lang'][$langList] );
}
}
}
// Remove 'deprecated' key
if ( is_array( $this->descriptor ) ) {
unset( $this->descriptor['deprecated'] );
}
// Ensure that all files have common extension.
$extensions = [];
$descriptor = is_array( $this->descriptor ) ? $this->descriptor : [ $this->descriptor ];
array_walk_recursive( $descriptor, function ( $path ) use ( &$extensions ) {
$extensions[] = pathinfo( $this->getLocalPath( $path ), PATHINFO_EXTENSION );
} );
$extensions = array_unique( $extensions );
if ( count( $extensions ) !== 1 ) {
throw new InvalidArgumentException(
"File type for different image files of '$name' not the same in module '$module'"
);
}
$ext = $extensions[0];
if ( !isset( self::FILE_TYPES[$ext] ) ) {
throw new InvalidArgumentException(
"Invalid file type for image files of '$name' (valid: svg, png, gif, jpg) in module '$module'"
);
}
$this->extension = $ext;
}
/**
* Get name of this image.
*
* @return string
*/
public function getName() {
return $this->name;
}
/**
* Get name of the module this image belongs to.
*
* @return string
*/
public function getModule() {
return $this->module;
}
/**
* Get the list of variants this image can be converted to.
*
* @return string[]
*/
public function getVariants(): array {
return array_keys( $this->variants );
}
/**
* @internal For unit testing override
* @param string $lang
* @return string[]
*/
protected function getLangFallbacks( string $lang ): array {
return MediaWikiServices::getInstance()
->getLanguageFallback()
->getAll( $lang, LanguageFallback::STRICT );
}
/**
* Get the path to image file for given context.
*
* @param Context $context Any context
* @return string
*/
public function getPath( Context $context ) {
$desc = $this->descriptor;
if ( !is_array( $desc ) ) {
return $this->getLocalPath( $desc );
}
if ( isset( $desc['lang'] ) ) {
$contextLang = $context->getLanguage();
if ( isset( $desc['lang'][$contextLang] ) ) {
return $this->getLocalPath( $desc['lang'][$contextLang] );
}
$fallbacks = $this->getLangFallbacks( $contextLang );
foreach ( $fallbacks as $lang ) {
if ( isset( $desc['lang'][$lang] ) ) {
return $this->getLocalPath( $desc['lang'][$lang] );
}
}
}
if ( isset( $desc[$context->getDirection()] ) ) {
return $this->getLocalPath( $desc[$context->getDirection()] );
}
if ( isset( $desc['default'] ) ) {
return $this->getLocalPath( $desc['default'] );
}
throw new RuntimeException( 'No matching path found' );
}
/**
* @param string|FilePath $path
* @return string
*/
protected function getLocalPath( $path ) {
if ( $path instanceof FilePath ) {
return $path->getLocalPath();
}
return "{$this->basePath}/$path";
}
/**
* Get the extension of the image.
*
* @param string|null $format Format to get the extension for, 'original' or 'rasterized'
* @return string Extension without leading dot, e.g. 'png'
*/
public function getExtension( $format = 'original' ) {
if ( $format === 'rasterized' && $this->extension === 'svg' ) {
return 'png';
}
return $this->extension;
}
/**
* Get the MIME type of the image.
*
* @param string|null $format Format to get the MIME type for, 'original' or 'rasterized'
* @return string
*/
public function getMimeType( $format = 'original' ) {
$ext = $this->getExtension( $format );
return self::FILE_TYPES[$ext];
}
/**
* Get the load.php URL that will produce this image.
*
* @param Context $context Any context
* @param string $script URL to load.php
* @param string|null $variant Variant to get the URL for
* @param string $format Format to get the URL for, 'original' or 'rasterized'
* @return string URL
*/
public function getUrl( Context $context, $script, $variant, $format ) {
$query = [
'modules' => $this->getModule(),
'image' => $this->getName(),
'variant' => $variant,
'format' => $format,
// Most images don't vary on language, but include the parameter anyway, so that version
// hashes are computed consistently. (T321394#9100166)
'lang' => $context->getLanguage(),
'skin' => $context->getSkin(),
'version' => $context->getResourceLoader()->makeVersionQuery( $context, [ $this->getModule() ] ),
];
return wfAppendQuery( $script, $query );
}
/**
* Get the data: URI that will produce this image.
*
* @param Context $context Any context
* @param string|null $variant Variant to get the URI for
* @param string $format Format to get the URI for, 'original' or 'rasterized'
* @return string
*/
public function getDataUri( Context $context, $variant, $format ) {
$type = $this->getMimeType( $format );
$contents = $this->getImageData( $context, $variant, $format );
return CSSMin::encodeStringAsDataURI( $contents, $type );
}
/**
* Get actual image data for this image. This can be saved to a file or sent to the browser to
* produce the converted image.
*
* Call getExtension() or getMimeType() with the same $format argument to learn what file type the
* returned data uses.
*
* @param Context $context Image context, or any context if $variant and $format
* given.
* @param string|null|false $variant Variant to get the data for. Optional; if given, overrides the data
* from $context.
* @param string|false $format Format to get the data for, 'original' or 'rasterized'. Optional; if
* given, overrides the data from $context.
* @return string|false Possibly binary image data, or false on failure
*/
public function getImageData( Context $context, $variant = false, $format = false ) {
if ( $variant === false ) {
$variant = $context->getVariant();
}
if ( $format === false ) {
$format = $context->getFormat();
}
$path = $this->getPath( $context );
if ( !file_exists( $path ) ) {
throw new RuntimeException( "File '$path' does not exist" );
}
if ( $this->getExtension() !== 'svg' ) {
return file_get_contents( $path );
}
if ( $variant && isset( $this->variants[$variant] ) ) {
$data = $this->variantize( $this->variants[$variant], $context );
} else {
$defaultColor = $this->defaultColor;
$data = $defaultColor ?
$this->variantize( [ 'color' => $defaultColor ], $context ) :
file_get_contents( $path );
}
if ( $format === 'rasterized' ) {
$data = $this->rasterize( $data );
if ( !$data ) {
$logger = $context->getResourceLoader()->getLogger();
$logger->error( __METHOD__ . " failed to rasterize for $path" );
}
}
return $data;
}
/**
* Send response headers (using the header() function) that are necessary to correctly serve the
* image data for this image, as returned by getImageData().
*
* Note that the headers are independent of the language or image variant.
*
* @param Context $context Image context
*/
public function sendResponseHeaders( Context $context ): void {
$format = $context->getFormat();
$mime = $this->getMimeType( $format );
$filename = $this->getName() . '.' . $this->getExtension( $format );
header( 'Content-Type: ' . $mime );
header( 'Content-Disposition: ' .
FileBackend::makeContentDisposition( 'inline', $filename ) );
header( 'Access-Control-Allow-Origin: *' );
}
/**
* Convert this image, which is assumed to be SVG, to given variant.
*
* @param array $variantConf Array with a 'color' key, its value will be used as fill color
* @param Context $context Image context
* @return string New SVG file data
*/
protected function variantize( array $variantConf, Context $context ) {
$dom = new DOMDocument;
$dom->loadXML( file_get_contents( $this->getPath( $context ) ) );
$root = $dom->documentElement;
$titleNode = null;
$wrapper = $dom->createElementNS( 'http://www.w3.org/2000/svg', 'g' );
// Reattach all direct children of the `<svg>` root node to the `<g>` wrapper
while ( $root->firstChild ) {
$node = $root->firstChild;
'@phan-var \DOMElement $node'; /** @var \DOMElement $node */
if ( !$titleNode && $node->nodeType === XML_ELEMENT_NODE && $node->tagName === 'title' ) {
// Remember the first encountered `<title>` node
$titleNode = $node;
}
$wrapper->appendChild( $node );
}
if ( $titleNode ) {
// Reattach the `<title>` node to the `<svg>` root node rather than the `<g>` wrapper
$root->appendChild( $titleNode );
}
$root->appendChild( $wrapper );
$wrapper->setAttribute( 'fill', $variantConf['color'] );
return $dom->saveXML();
}
/**
* Massage the SVG image data for converters which don't understand some path data syntax.
*
* This is necessary for rsvg and ImageMagick when compiled with rsvg support.
* Upstream bug is https://bugzilla.gnome.org/show_bug.cgi?id=620923, fixed 2014-11-10, so
* this will be needed for a while. (T76852)
*
* @param string $svg SVG image data
* @return string Massaged SVG image data
*/
protected function massageSvgPathdata( $svg ) {
$dom = new DOMDocument;
$dom->loadXML( $svg );
foreach ( $dom->getElementsByTagName( 'path' ) as $node ) {
$pathData = $node->getAttribute( 'd' );
// Make sure there is at least one space between numbers, and that leading zero is not omitted.
// rsvg has issues with syntax like "M-1-2" and "M.445.483" and especially "M-.445-.483".
$pathData = preg_replace( '/(-?)(\d*\.\d+|\d+)/', ' ${1}0$2 ', $pathData );
// Strip unnecessary leading zeroes for prettiness, not strictly necessary
$pathData = preg_replace( '/([ -])0(\d)/', '$1$2', $pathData );
$node->setAttribute( 'd', $pathData );
}
return $dom->saveXML();
}
/**
* Convert passed image data, which is assumed to be SVG, to PNG.
*
* @param string $svg SVG image data
* @return string|bool PNG image data, or false on failure
*/
protected function rasterize( $svg ) {
$svgConverter = MediaWikiServices::getInstance()->getMainConfig()->get( MainConfigNames::SVGConverter );
$svgConverterPath = MediaWikiServices::getInstance()->getMainConfig()->get( MainConfigNames::SVGConverterPath );
// This code should be factored out to a separate method on SvgHandler, or perhaps a separate
// class, with a separate set of configuration settings.
//
// This is a distinct use case from regular SVG rasterization:
// * We can skip many checks (as the images come from a trusted source,
// rather than from the user).
// * We need to provide extra options to some converters to achieve acceptable quality for very
// small images, which might cause performance issues in the general case.
// * We want to directly pass image data to the converter, rather than a file path.
//
// See https://phabricator.wikimedia.org/T76473#801446 for examples of what happens with the
// default settings.
//
// For now, we special-case rsvg (used in WMF production) and do a messy workaround for other
// converters.
$svg = $this->massageSvgPathdata( $svg );
// Sometimes this might be 'rsvg-secure'. Long as it's rsvg.
if ( strpos( $svgConverter, 'rsvg' ) === 0 ) {
$command = 'rsvg-convert';
if ( $svgConverterPath ) {
$command = Shell::escape( "{$svgConverterPath}/" ) . $command;
}
$process = proc_open(
$command,
[ 0 => [ 'pipe', 'r' ], 1 => [ 'pipe', 'w' ] ],
$pipes
);
if ( $process ) {
fwrite( $pipes[0], $svg );
fclose( $pipes[0] );
$png = stream_get_contents( $pipes[1] );
fclose( $pipes[1] );
proc_close( $process );
return $png ?: false;
}
return false;
}
// Write input to and read output from a temporary file
$tempFilenameSvg = tempnam( wfTempDir(), 'ResourceLoaderImage' );
$tempFilenamePng = tempnam( wfTempDir(), 'ResourceLoaderImage' );
file_put_contents( $tempFilenameSvg, $svg );
try {
$svgReader = new SVGReader( $tempFilenameSvg );
} catch ( InvalidSVGException $e ) {
// XXX Can this ever happen?
throw new RuntimeException( 'Invalid SVG', 0, $e );
}
$metadata = $svgReader->getMetadata();
if ( !isset( $metadata['width'] ) || !isset( $metadata['height'] ) ) {
unlink( $tempFilenameSvg );
return false;
}
$handler = new SvgHandler;
$res = $handler->rasterize(
$tempFilenameSvg,
$tempFilenamePng,
$metadata['width'],
$metadata['height']
);
unlink( $tempFilenameSvg );
if ( $res === true ) {
$png = file_get_contents( $tempFilenamePng );
unlink( $tempFilenamePng );
return $png;
}
return false;
}
}