return $svg->getMetadata();
}
}
-
-/**
- * @ingroup Media
- */
-class SVGReader {
- const DEFAULT_WIDTH = 512;
- const DEFAULT_HEIGHT = 512;
- const NS_SVG = 'http://www.w3.org/2000/svg';
- const LANG_PREFIX_MATCH = 1;
- const LANG_FULL_MATCH = 2;
-
- /** @var null|XMLReader */
- private $reader = null;
-
- /** @var bool */
- private $mDebug = false;
-
- /** @var array */
- private $metadata = [];
- private $languages = [];
- private $languagePrefixes = [];
-
- /**
- * Creates an SVGReader drawing from the source provided
- * @param string $source URI from which to read
- * @throws MWException|Exception
- */
- function __construct( $source ) {
- global $wgSVGMetadataCutoff;
- $this->reader = new XMLReader();
-
- // Don't use $file->getSize() since file object passed to SVGHandler::getMetadata is bogus.
- $size = filesize( $source );
- if ( $size === false ) {
- throw new MWException( "Error getting filesize of SVG." );
- }
-
- if ( $size > $wgSVGMetadataCutoff ) {
- $this->debug( "SVG is $size bytes, which is bigger than $wgSVGMetadataCutoff. Truncating." );
- $contents = file_get_contents( $source, false, null, 0, $wgSVGMetadataCutoff );
- if ( $contents === false ) {
- throw new MWException( 'Error reading SVG file.' );
- }
- $this->reader->XML( $contents, null, LIBXML_NOERROR | LIBXML_NOWARNING );
- } else {
- $this->reader->open( $source, null, LIBXML_NOERROR | LIBXML_NOWARNING );
- }
-
- // Expand entities, since Adobe Illustrator uses them for xmlns
- // attributes (T33719). Note that libxml2 has some protection
- // against large recursive entity expansions so this is not as
- // insecure as it might appear to be. However, it is still extremely
- // insecure. It's necessary to wrap any read() calls with
- // libxml_disable_entity_loader() to avoid arbitrary local file
- // inclusion, or even arbitrary code execution if the expect
- // extension is installed (T48859).
- $oldDisable = libxml_disable_entity_loader( true );
- $this->reader->setParserProperty( XMLReader::SUBST_ENTITIES, true );
-
- $this->metadata['width'] = self::DEFAULT_WIDTH;
- $this->metadata['height'] = self::DEFAULT_HEIGHT;
-
- // The size in the units specified by the SVG file
- // (for the metadata box)
- // Per the SVG spec, if unspecified, default to '100%'
- $this->metadata['originalWidth'] = '100%';
- $this->metadata['originalHeight'] = '100%';
-
- // Because we cut off the end of the svg making an invalid one. Complicated
- // try catch thing to make sure warnings get restored. Seems like there should
- // be a better way.
- Wikimedia\suppressWarnings();
- try {
- $this->read();
- } catch ( Exception $e ) {
- // Note, if this happens, the width/height will be taken to be 0x0.
- // Should we consider it the default 512x512 instead?
- Wikimedia\restoreWarnings();
- libxml_disable_entity_loader( $oldDisable );
- throw $e;
- }
- Wikimedia\restoreWarnings();
- libxml_disable_entity_loader( $oldDisable );
- }
-
- /**
- * @return array Array with the known metadata
- */
- public function getMetadata() {
- return $this->metadata;
- }
-
- /**
- * Read the SVG
- * @throws MWException
- * @return bool
- */
- protected function read() {
- $keepReading = $this->reader->read();
-
- /* Skip until first element */
- while ( $keepReading && $this->reader->nodeType != XMLReader::ELEMENT ) {
- $keepReading = $this->reader->read();
- }
-
- if ( $this->reader->localName != 'svg' || $this->reader->namespaceURI != self::NS_SVG ) {
- throw new MWException( "Expected <svg> tag, got " .
- $this->reader->localName . " in NS " . $this->reader->namespaceURI );
- }
- $this->debug( "<svg> tag is correct." );
- $this->handleSVGAttribs();
-
- $exitDepth = $this->reader->depth;
- $keepReading = $this->reader->read();
- while ( $keepReading ) {
- $tag = $this->reader->localName;
- $type = $this->reader->nodeType;
- $isSVG = ( $this->reader->namespaceURI == self::NS_SVG );
-
- $this->debug( "$tag" );
-
- if ( $isSVG && $tag == 'svg' && $type == XMLReader::END_ELEMENT
- && $this->reader->depth <= $exitDepth
- ) {
- break;
- } elseif ( $isSVG && $tag == 'title' ) {
- $this->readField( $tag, 'title' );
- } elseif ( $isSVG && $tag == 'desc' ) {
- $this->readField( $tag, 'description' );
- } elseif ( $isSVG && $tag == 'metadata' && $type == XMLReader::ELEMENT ) {
- $this->readXml( 'metadata' );
- } elseif ( $isSVG && $tag == 'script' ) {
- // We normally do not allow scripted svgs.
- // However its possible to configure MW to let them
- // in, and such files should be considered animated.
- $this->metadata['animated'] = true;
- } elseif ( $tag !== '#text' ) {
- $this->debug( "Unhandled top-level XML tag $tag" );
-
- // Recurse into children of current tag, looking for animation and languages.
- $this->animateFilterAndLang( $tag );
- }
-
- // Goto next element, which is sibling of current (Skip children).
- $keepReading = $this->reader->next();
- }
-
- $this->reader->close();
-
- $this->metadata['translations'] = $this->languages + $this->languagePrefixes;
-
- return true;
- }
-
- /**
- * Read a textelement from an element
- *
- * @param string $name Name of the element that we are reading from
- * @param string $metafield Field that we will fill with the result
- */
- private function readField( $name, $metafield = null ) {
- $this->debug( "Read field $metafield" );
- if ( !$metafield || $this->reader->nodeType != XMLReader::ELEMENT ) {
- return;
- }
- $keepReading = $this->reader->read();
- while ( $keepReading ) {
- if ( $this->reader->localName == $name
- && $this->reader->namespaceURI == self::NS_SVG
- && $this->reader->nodeType == XMLReader::END_ELEMENT
- ) {
- break;
- } elseif ( $this->reader->nodeType == XMLReader::TEXT ) {
- $this->metadata[$metafield] = trim( $this->reader->value );
- }
- $keepReading = $this->reader->read();
- }
- }
-
- /**
- * Read an XML snippet from an element
- *
- * @param string $metafield Field that we will fill with the result
- * @throws MWException
- */
- private function readXml( $metafield = null ) {
- $this->debug( "Read top level metadata" );
- if ( !$metafield || $this->reader->nodeType != XMLReader::ELEMENT ) {
- return;
- }
- // @todo Find and store type of xml snippet. metadata['metadataType'] = "rdf"
- $this->metadata[$metafield] = trim( $this->reader->readInnerXml() );
-
- $this->reader->next();
- }
-
- /**
- * Filter all children, looking for animated elements.
- * Also get a list of languages that can be targeted.
- *
- * @param string $name Name of the element that we are reading from
- */
- private function animateFilterAndLang( $name ) {
- $this->debug( "animate filter for tag $name" );
- if ( $this->reader->nodeType != XMLReader::ELEMENT ) {
- return;
- }
- if ( $this->reader->isEmptyElement ) {
- return;
- }
- $exitDepth = $this->reader->depth;
- $keepReading = $this->reader->read();
- while ( $keepReading ) {
- if ( $this->reader->localName == $name && $this->reader->depth <= $exitDepth
- && $this->reader->nodeType == XMLReader::END_ELEMENT
- ) {
- break;
- } elseif ( $this->reader->namespaceURI == self::NS_SVG
- && $this->reader->nodeType == XMLReader::ELEMENT
- ) {
- $sysLang = $this->reader->getAttribute( 'systemLanguage' );
- if ( !is_null( $sysLang ) && $sysLang !== '' ) {
- // See https://www.w3.org/TR/SVG/struct.html#SystemLanguageAttribute
- $langList = explode( ',', $sysLang );
- foreach ( $langList as $langItem ) {
- $langItem = trim( $langItem );
- if ( Language::isWellFormedLanguageTag( $langItem ) ) {
- $this->languages[$langItem] = self::LANG_FULL_MATCH;
- }
- // Note, the standard says that any prefix should work,
- // here we do only the initial prefix, since that will catch
- // 99% of cases, and we are going to compare against fallbacks.
- // This differs mildly from how the spec says languages should be
- // handled, however it matches better how the MediaWiki language
- // preference is generally handled.
- $dash = strpos( $langItem, '-' );
- // Intentionally checking both !false and > 0 at the same time.
- if ( $dash ) {
- $itemPrefix = substr( $langItem, 0, $dash );
- if ( Language::isWellFormedLanguageTag( $itemPrefix ) ) {
- $this->languagePrefixes[$itemPrefix] = self::LANG_PREFIX_MATCH;
- }
- }
- }
- }
- switch ( $this->reader->localName ) {
- case 'script':
- // Normally we disallow files with
- // <script>, but its possible
- // to configure MW to disable
- // such checks.
- case 'animate':
- case 'set':
- case 'animateMotion':
- case 'animateColor':
- case 'animateTransform':
- $this->debug( "HOUSTON WE HAVE ANIMATION" );
- $this->metadata['animated'] = true;
- break;
- }
- }
- $keepReading = $this->reader->read();
- }
- }
-
- private function debug( $data ) {
- if ( $this->mDebug ) {
- wfDebug( "SVGReader: $data\n" );
- }
- }
-
- /**
- * Parse the attributes of an SVG element
- *
- * The parser has to be in the start element of "<svg>"
- */
- private function handleSVGAttribs() {
- $defaultWidth = self::DEFAULT_WIDTH;
- $defaultHeight = self::DEFAULT_HEIGHT;
- $aspect = 1.0;
- $width = null;
- $height = null;
-
- if ( $this->reader->getAttribute( 'viewBox' ) ) {
- // min-x min-y width height
- $viewBox = preg_split( '/\s*[\s,]\s*/', trim( $this->reader->getAttribute( 'viewBox' ) ) );
- if ( count( $viewBox ) == 4 ) {
- $viewWidth = $this->scaleSVGUnit( $viewBox[2] );
- $viewHeight = $this->scaleSVGUnit( $viewBox[3] );
- if ( $viewWidth > 0 && $viewHeight > 0 ) {
- $aspect = $viewWidth / $viewHeight;
- $defaultHeight = $defaultWidth / $aspect;
- }
- }
- }
- if ( $this->reader->getAttribute( 'width' ) ) {
- $width = $this->scaleSVGUnit( $this->reader->getAttribute( 'width' ), $defaultWidth );
- $this->metadata['originalWidth'] = $this->reader->getAttribute( 'width' );
- }
- if ( $this->reader->getAttribute( 'height' ) ) {
- $height = $this->scaleSVGUnit( $this->reader->getAttribute( 'height' ), $defaultHeight );
- $this->metadata['originalHeight'] = $this->reader->getAttribute( 'height' );
- }
-
- if ( !isset( $width ) && !isset( $height ) ) {
- $width = $defaultWidth;
- $height = $width / $aspect;
- } elseif ( isset( $width ) && !isset( $height ) ) {
- $height = $width / $aspect;
- } elseif ( isset( $height ) && !isset( $width ) ) {
- $width = $height * $aspect;
- }
-
- if ( $width > 0 && $height > 0 ) {
- $this->metadata['width'] = intval( round( $width ) );
- $this->metadata['height'] = intval( round( $height ) );
- }
- }
-
- /**
- * Return a rounded pixel equivalent for a labeled CSS/SVG length.
- * https://www.w3.org/TR/SVG11/coords.html#Units
- *
- * @param string $length CSS/SVG length.
- * @param float|int $viewportSize Optional scale for percentage units...
- * @return float Length in pixels
- */
- static function scaleSVGUnit( $length, $viewportSize = 512 ) {
- static $unitLength = [
- 'px' => 1.0,
- 'pt' => 1.25,
- 'pc' => 15.0,
- 'mm' => 3.543307,
- 'cm' => 35.43307,
- 'in' => 90.0,
- 'em' => 16.0, // fake it?
- 'ex' => 12.0, // fake it?
- '' => 1.0, // "User units" pixels by default
- ];
- $matches = [];
- if ( preg_match(
- '/^\s*([-+]?\d*(?:\.\d+|\d+)(?:[Ee][-+]?\d+)?)\s*(em|ex|px|pt|pc|cm|mm|in|%|)\s*$/',
- $length,
- $matches
- ) ) {
- $length = floatval( $matches[1] );
- $unit = $matches[2];
- if ( $unit == '%' ) {
- return $length * 0.01 * $viewportSize;
- } else {
- return $length * $unitLength[$unit];
- }
- } else {
- // Assume pixels
- return floatval( $length );
- }
- }
-}
dépôts / lhc / web / wiklou.git / blobdiff