<?php
/**
- * SVGMetadataExtractor.php
+ * Extraction of SVG image metadata.
*
* 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
*
* @file
* @ingroup Media
- * @author Derk-Jan Hartman <hartman _at_ videolan d0t org>
+ * @author "Derk-Jan Hartman <hartman _at_ videolan d0t org>"
* @author Brion Vibber
* @copyright Copyright © 2010-2010 Brion Vibber, Derk-Jan Hartman
* @license http://www.gnu.org/copyleft/gpl.html GNU General Public License
*/
+/**
+ * @ingroup Media
+ */
class SVGMetadataExtractor {
static function getMetadata( $filename ) {
$svg = new SVGReader( $filename );
+
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;
- private $metadata = Array();
+
+ /** @var array */
+ private $metadata = [];
+ private $languages = [];
+ private $languagePrefixes = [];
/**
- * Constructor
- *
* Creates an SVGReader drawing from the source provided
- * @param $source String: URI from which to read
+ * @param string $source URI from which to read
+ * @throws MWException|Exception
*/
function __construct( $source ) {
global $wgSVGMetadataCutoff;
$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, -1, $wgSVGMetadataCutoff );
- if ($contents === false) {
+ if ( $contents === false ) {
throw new MWException( 'Error reading SVG file.' );
}
$this->reader->XML( $contents, null, LIBXML_NOERROR | LIBXML_NOWARNING );
$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.
- wfSuppressWarnings();
+ MediaWiki\suppressWarnings();
try {
$this->read();
- } catch( Exception $e ) {
- wfRestoreWarnings();
+ } catch ( Exception $e ) {
+ // Note, if this happens, the width/height will be taken to be 0x0.
+ // Should we consider it the default 512x512 instead?
+ MediaWiki\restoreWarnings();
+ libxml_disable_entity_loader( $oldDisable );
throw $e;
}
- wfRestoreWarnings();
+ MediaWiki\restoreWarnings();
+ libxml_disable_entity_loader( $oldDisable );
}
- /*
- * @return Array with the known metadata
+ /**
+ * @return array Array with the known metadata
*/
public function getMetadata() {
return $this->metadata;
}
- /*
+ /**
* Read the SVG
+ * @throws MWException
+ * @return bool
*/
- public function read() {
+ protected function read() {
$keepReading = $this->reader->read();
/* Skip until first element */
- while( $keepReading && $this->reader->nodeType != XmlReader::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 ".
+ 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;
+ $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);
+ $isSVG = ( $this->reader->namespaceURI == self::NS_SVG );
$this->debug( "$tag" );
- if ( $isSVG && $tag == 'svg' && $type == XmlReader::END_ELEMENT && $this->reader->depth <= $exitDepth ) {
+ 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 ) {
+ } elseif ( $isSVG && $tag == 'metadata' && $type == XMLReader::ELEMENT ) {
$this->readXml( $tag, '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" );
- if ( !isset( $this->metadata['animated'] ) ) {
- // Recurse into children of current tag, looking for animation.
- $this->animateFilter( $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 of the element that we are reading from
- * @param String $metafield that we will fill with the result
+ * @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 ) {
+ 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->namespaceURI == self::NS_SVG && $this->reader->nodeType == XmlReader::END_ELEMENT ) {
+ 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 ){
+ } 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 that we will fill with the result
+ * @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 ) {
+ 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() );
+ // @todo Find and store type of xml snippet. metadata['metadataType'] = "rdf"
+ if ( method_exists( $this->reader, 'readInnerXML' ) ) {
+ $this->metadata[$metafield] = trim( $this->reader->readInnerXml() );
+ } else {
+ throw new MWException( "The PHP XMLReader extension does not come " .
+ "with readInnerXML() method. Your libxml is probably out of " .
+ "date (need 2.6.20 or later)." );
+ }
$this->reader->next();
}
- /*
- * Filter all children, looking for animate elements
+ /**
+ * Filter all children, looking for animated elements.
+ * Also get a list of languages that can be targeted.
*
- * @param String $name of the element that we are reading from
+ * @param string $name Name of the element that we are reading from
*/
- private function animateFilter( $name ) {
- $this->debug ( "animate filter" );
- if( $this->reader->nodeType != XmlReader::ELEMENT ) {
+ 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;
+ $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 ) {
+ 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 ) {
- switch( $this->reader->localName ) {
+ } 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':
}
}
- private function throwXmlError( $err ) {
- $this->debug( "FAILURE: $err" );
- wfDebug( "SVGReader XML error: $err\n" );
- }
-
private function debug( $data ) {
- if( $this->mDebug ) {
+ if ( $this->mDebug ) {
wfDebug( "SVGReader: $data\n" );
}
}
- private function warn( $data ) {
- wfDebug( "SVGReader: $data\n" );
- }
-
- private function notice( $data ) {
- wfDebug( "SVGReader WARN: $data\n" );
- }
-
- /*
+ /**
* Parse the attributes of an SVG element
*
- * The parser has to be in the start element of <svg>
+ * The parser has to be in the start element of "<svg>"
*/
- private function handleSVGAttribs( ) {
+ private function handleSVGAttribs() {
$defaultWidth = self::DEFAULT_WIDTH;
$defaultHeight = self::DEFAULT_HEIGHT;
$aspect = 1.0;
$width = null;
$height = null;
- if( $this->reader->getAttribute('viewBox') ) {
+ if ( $this->reader->getAttribute( 'viewBox' ) ) {
// min-x min-y width height
- $viewBox = preg_split( '/\s+/', trim( $this->reader->getAttribute('viewBox') ) );
- if( count( $viewBox ) == 4 ) {
+ $viewBox = preg_split( '/\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 ) {
+ if ( $viewWidth > 0 && $viewHeight > 0 ) {
$aspect = $viewWidth / $viewHeight;
$defaultHeight = $defaultWidth / $aspect;
}
}
}
- if( $this->reader->getAttribute('width') ) {
- $width = $this->scaleSVGUnit( $this->reader->getAttribute('width'), $defaultWidth );
+ 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 );
+ 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 ) ) {
+ if ( !isset( $width ) && !isset( $height ) ) {
$width = $defaultWidth;
$height = $width / $aspect;
- } elseif( isset( $width ) && !isset( $height ) ) {
+ } elseif ( isset( $width ) && !isset( $height ) ) {
$height = $width / $aspect;
- } elseif( isset( $height ) && !isset( $width ) ) {
+ } elseif ( isset( $height ) && !isset( $width ) ) {
$width = $height * $aspect;
}
- if( $width > 0 && $height > 0 ) {
+ 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.
- * http://www.w3.org/TR/SVG11/coords.html#UnitIdentifiers
+ * https://www.w3.org/TR/SVG11/coords.html#Units
*
- * @param $length String: CSS/SVG length.
- * @param $viewportSize: Float optional scale for percentage units...
- * @return float: length in pixels
+ * @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 = array(
+ static function scaleSVGUnit( $length, $viewportSize = 512 ) {
+ static $unitLength = [
'px' => 1.0,
'pt' => 1.25,
'pc' => 15.0,
'in' => 90.0,
'em' => 16.0, // fake it?
'ex' => 12.0, // fake it?
- '' => 1.0, // "User units" pixels by default
- );
- $matches = array();
- if( preg_match( '/^\s*(\d+(?:\.\d+)?)(em|ex|px|pt|pc|cm|mm|in|%|)\s*$/', $length, $matches ) ) {
+ '' => 1.0, // "User units" pixels by default
+ ];
+ $matches = [];
+ if ( preg_match( '/^\s*(\d+(?:\.\d+)?)(em|ex|px|pt|pc|cm|mm|in|%|)\s*$/', $length, $matches ) ) {
$length = floatval( $matches[1] );
$unit = $matches[2];
- if( $unit == '%' ) {
+ if ( $unit == '%' ) {
return $length * 0.01 * $viewportSize;
} else {
return $length * $unitLength[$unit];
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