mediawiki-extensions-Math/MathMathML.php
Gabriel Wicke fd7fcc6ada Remove PNG image fallback image references
- These images currently return server errors

- We don't really want to load PNG images for browsers that support MathML or
  SVG. 

Bug: 69702
Change-Id: Idd339623efd19a0726b43a6c4adc2fcd832511f6
2014-10-09 05:50:04 +00:00

486 lines
14 KiB
PHP

<?php
/**
* MediaWiki math extension
*
* (c)2012 Moritz Schubotz
* GPLv2 license; info in main package.
*
* Contains the driver function for the MathML daemon
* @file
*/
class MathMathML extends MathRenderer {
protected $defaultAllowedRootElements = array( 'math' );
protected $allowedRootElements = '';
protected $hosts;
/** @var boolean if false MathML output is not validated */
private $XMLValidation = true;
protected $inputType = 'tex';
/**
* @param string $inputType
*/
public function setInputType($inputType)
{
$this->inputType = $inputType;
}
/**
* @return string
*/
public function getInputType()
{
return $this->inputType;
}
public function __construct( $tex = '', $params = array() ) {
global $wgMathMathMLUrl;
parent::__construct( $tex, $params );
$this->setMode( MW_MATH_MATHML );
$this->hosts = $wgMathMathMLUrl;
if ( isset( $params['type'] ) ) {
if ( $params['type'] == 'pmml' ) {
$this->inputType = 'pmml';
$this->setMathml( '<math>' . $tex . '</math>' );
} elseif ( $params['type'] == 'ascii' ) {
$this->inputType = 'ascii';
}
}
}
/**
* Gets the allowed root elements the rendered math tag might have.
*
* @return array
*/
public function getAllowedRootElements() {
if ( $this->allowedRootElements ) {
return $this->allowedRootElements;
} else {
return $this->defaultAllowedRootElements;
}
}
/**
* Sets the XML validation.
* If set to false the output of MathML is not validated.
* @param boolean $validation
*/
public function setXMLValidation( $validation = true ) {
$this->XMLValidation = $validation;
}
/**
* Sets the allowed root elements the rendered math tag might have.
* An empty value indicates to use the default settings.
* @param array $settings
*/
public function setAllowedRootElements( $settings ) {
$this->allowedRootElements = $settings;
}
/* (non-PHPdoc)
* @see MathRenderer::render()
*/
public function render( $forceReRendering = false ) {
wfProfileIn( __METHOD__ );
if ( $forceReRendering ) {
$this->setPurge( true );
}
if ( $this->renderingRequired() ) {
wfProfileOut( __METHOD__ );
return $this->doRender( );
}
wfProfileOut( __METHOD__ );
return true;
}
/**
* Helper function to checks if the math tag must be rendered.
* @return boolean
*/
private function renderingRequired() {
if ( $this->isPurge() ) {
wfDebugLog( "Math", "Rerendering was requested." );
return true;
} else {
$dbres = $this->isInDatabase();
if ( $dbres ) {
if ( $this->isValidMathML( $this->getMathml() ) ) {
wfDebugLog( "Math", "Valid MathML entry found in database." );
if ( $this->getSvg() ) {
wfDebugLog( "Math", "SVG-fallback found in database." );
return false;
} else {
wfDebugLog( "Math", "SVG-fallback missing." );
return true;
}
} else {
wfDebugLog( "Math", "Malformatted entry found in database" );
return true;
}
} else {
wfDebugLog( "Math", "No entry found in database." );
return true;
}
}
}
/**
* Performs a HTTP Post request to the given host.
* Uses $wgMathLaTeXMLTimeout as timeout.
* Generates error messages on failure
* @see Http::post()
*
* @global int $wgMathLaTeXMLTimeout
* @param string $host
* @param string $post the encoded post request
* @param mixed $res the result
* @param mixed $error the formatted error message or null
* @param String $httpRequestClass class name of MWHttpRequest (needed for testing only)
* @return boolean success
*/
public function makeRequest( $host, $post, &$res, &$error = '', $httpRequestClass = 'MWHttpRequest' ) {
// TODO: Change the timeout mechanism.
global $wgMathLaTeXMLTimeout;
wfProfileIn( __METHOD__ );
$error = '';
$res = null;
if ( !$host ) {
$host = self::pickHost();
}
if ( !$post ) {
$this->getPostData();
}
$options = array( 'method' => 'POST', 'postData' => $post, 'timeout' => $wgMathLaTeXMLTimeout );
/** @var $req (CurlHttpRequest|PhpHttpRequest) the request object */
$req = $httpRequestClass::factory( $host, $options );
/** @var Status the request status */
$status = $req->execute();
if ( $status->isGood() ) {
$res = $req->getContent();
wfProfileOut( __METHOD__ );
return true;
} else {
if ( $status->hasMessage( 'http-timed-out' ) ) {
$error = $this->getError( 'math_timeout', $this->getModeStr(), $host );
$res = false;
wfDebugLog( "Math", "\nTimeout:"
. var_export( array( 'post' => $post, 'host' => $host
, 'timeout' => $wgMathLaTeXMLTimeout ), true ) . "\n\n" );
} else {
// for any other unkonwn http error
$errormsg = $status->getHtml();
$error = $this->getError( 'math_invalidresponse', $this->getModeStr(), $host, $errormsg, $this->getModeStr( MW_MATH_MATHML ) );
wfDebugLog( "Math", "\nNoResponse:"
. var_export( array( 'post' => $post, 'host' => $host
, 'errormsg' => $errormsg ), true ) . "\n\n" );
}
wfProfileOut( __METHOD__ );
return false;
}
}
/**
* Picks a MathML daemon.
* If more than one demon are available one is chosen from the
* $wgMathMathMLUrl array.
* @return string
*/
protected function pickHost() {
if ( is_array( $this->hosts ) ) {
$host = array_rand( $this->hosts );
} else {
$host = $this->hosts;
}
wfDebugLog( "Math", "picking host " . $host );
return $host;
}
/**
* Calculates the HTTP POST Data for the request. Depends on the settings
* and the input string only.
* @return string HTTP POST data
*/
public function getPostData() {
$input = $this->getTex();
if ( $this->inputType == 'pmml' || $this->getMode() == MW_MATH_LATEXML && $this->getMathml() ) {
$out = 'type=mml&q=' . rawurlencode( $this->getMathml() );
} elseif ( $this->inputType == 'ascii' ) {
$out = 'type=asciimath&q=' . rawurlencode( $input );
} else {
if ( $this->getMathStyle() == MW_MATHSTYLE_INLINE_DISPLAYSTYLE ) {
// default preserve the (broken) layout as it was
$out = 'type=inline-TeX&q=' .rawurlencode( '{\\displaystyle ' . $input . '}' );
} else {
$out = 'type=tex&q=' . rawurlencode( $input );
}
}
wfDebugLog( "Math", 'Get post data: ' . $out );
return $out;
}
/**
* Does the actual web request to convert TeX to MathML.
* @return boolean
*/
protected function doRender() {
global $wgMathDebug;
if ( $this->getTex() === '' ) {
wfDebugLog( 'Math', 'Rendering was requested, but no TeX string is specified.' );
$this->lastError = $this->getError( 'math_empty_tex' );
return false;
}
$res = '';
$host = self::pickHost();
$post = $this->getPostData();
$this->lastError = '';
$requestResult = $this->makeRequest( $host, $post, $res, $this->lastError );
if ( $requestResult ) {
$jsonResult = json_decode( $res );
if ( $jsonResult && json_last_error() === JSON_ERROR_NONE ) {
if ( $jsonResult->success ) {
if ( $this->getMode() == MW_MATH_LATEXML ||
$this->inputType == 'pmml' ||
$this->isValidMathML( $jsonResult->mml ) ) {
$xmlObject = new XmlTypeCheck( $jsonResult->svg, null, false );
if ( ! $xmlObject->wellFormed ) {
$this->lastError = $this->getError( 'math_invalidxml', $host );
return false;
} else {
$this->setSvg( $jsonResult->svg );
}
if ( $wgMathDebug ) {
$this->setLog( $jsonResult->log );
}
if ( $this->getMode() != MW_MATH_LATEXML && $this->inputType != 'pmml') {
$this->setMathml( $jsonResult->mml );
}
return true;
} else {
$this->lastError = $this->getError( 'math_unknown_error', $host );
return false;
}
} else {
if ( property_exists( $jsonResult, 'log' ) ) {
$log = $jsonResult->log;
} else {
$log = wfMessage( 'math_unknown_error' )->inContentLanguage()->escaped();
}
$this->lastError = $this->getError( 'math_mathoid_error', $host, $log );
wfDebugLog( 'Math', "Mathoid conversion error:"
. var_export( array( 'post' => $post, 'host' => $host
, 'result' => $res ), true ) . "\n\n" );
return false;
}
} else {
$this->lastError = $this->getError( 'math_invalidjson', $host );
wfDebugLog( 'Math', "\nMathML InvalidJSON:"
. var_export( array( 'post' => $post, 'host' => $host
, 'res' => $res ), true ) . "\n\n" );
return false;
}
} else {
// Error message has already been set.
return false;
}
}
/**
* Checks if the input is valid MathML,
* and if the root element has the name math
* @param string $XML
* @return boolean
*/
public function isValidMathML( $XML ) {
$out = false;
if ( !$this->XMLValidation ) {
return true;
}
// depends on https://gerrit.wikimedia.org/r/#/c/66365/
if ( !is_callable( 'XmlTypeCheck::newFromString' ) ) {
$msg = wfMessage( 'math_xmlversion' )->inContentLanguage()->escaped();
trigger_error( $msg, E_USER_NOTICE );
wfDebugLog( 'Math', $msg );
return true;
}
$xmlObject = new XmlTypeCheck( $XML, null, false );
if ( !$xmlObject->wellFormed ) {
wfDebugLog( "Math", "XML validation error:\n " . var_export( $XML, true ) . "\n" );
} else {
$name = $xmlObject->getRootElement();
$elementSplit = explode( ':', $name );
if ( is_array($elementSplit) ) {
$localName = end( $elementSplit );
} else {
$localName = $name;
}
if ( in_array( $localName , $this->getAllowedRootElements() ) ) {
$out = true;
} else {
wfDebugLog( "Math", "got wrong root element : $name" );
}
}
return $out;
}
/**
* @param int $mode
* @param boolean $noRender
* @return type
*/
private function getFallbackImageUrl( $mode = MW_MATH_MATHML, $noRender = false ) {
return SpecialPage::getTitleFor( 'MathShowImage' )->getLocalURL( array(
'hash' => $this->getMd5(),
'mode' => $mode,
'noRender' => $noRender )
);
}
/**
* Helper function to correct the style information for a
* linked SVG image.
* @param string $svg SVG-image data
* @param string $style current style information to be updated
*/
public function correctSvgStyle( $svg, &$style ) {
if ( preg_match( '/style="([^"]*)"/', $svg, $styles ) ) {
$style .= " ".$styles[1]; // merge styles
if ( $this->getMathStyle() === MW_MATHSTYLE_DISPLAY ) {
// TODO: Improve style cleaning
$style = preg_replace( '/margin\-(left|right)\:\s*\d+(\%|in|cm|mm|em|ex|pt|pc|px)\;/', '', $style );
}
}
// TODO: Figure out if there is a way to construct
// a SVGReader from a string that represents the SVG
// content
if ( preg_match( "/height=\"(.*?)\"/" , $this->getSvg(), $matches ) ) {
$style .= "height: " . $matches[1] . "; ";
}
if ( preg_match( "/width=\"(.*?)\"/", $this->getSvg(), $matches ) ) {
$style .= "width: " . $matches[1] . ";";
}
}
/**
* Gets img tag for math image
* @param int $mode if MW_MATH_PNG a png is used instead of an svg image
* @param boolean $noRender if true no rendering will be performed if the image is not stored in the database
* @param boolean|string $classOverride if classOverride is false the class name will be calculated by getClassName
* @return string XML the image html tag
*/
public function getFallbackImage( $mode = MW_MATH_MATHML, $noRender = false, $classOverride = false ) {
$url = $this->getFallbackImageUrl( $mode , $noRender );
if ( $mode == MW_MATH_PNG ) {
$png = true;
} else {
$png = false;
}
$attribs = array();
if ( $classOverride === false ) { // $class = '' suppresses class attribute
$class = $this->getClassName( true, $png );
$style = $png ? '' : 'display: none;';
} else {
$class = $classOverride;
$style = '';
}
if ( !$png ) {
$this->correctSvgStyle( $this->getSvg(), $style );
}
if ( $class ) { $attribs['class'] = $class; }
if ( $style ) { $attribs['style'] = $style; }
// an alternative for svg might be an object with type="image/svg+xml"
return Xml::element( 'img', $this->getAttributes( 'img', $attribs , array( 'src' => $url, 'aria-hidden' => 'true' ) ) );
}
protected function getMathTableName() {
return 'mathoid';
}
/**
* Calculates the default class name for a math element
* @param boolean $fallback
* @param boolean $png
* @return string the class name
*/
protected function getClassName( $fallback = false, $png = false ) {
$class = "mwe-math-";
if ( $fallback ) {
$class .= 'fallback-';
if ( $png ) {
$class .= 'png-';
} else {
$class .= 'svg-';
}
} else {
$class .= 'mathml-';
}
if ( $this->getMathStyle() == MW_MATHSTYLE_DISPLAY ) {
$class .= 'display';
} else {
$class .= 'inline';
}
return $class;
}
/**
* @return string Html output that is embedded in the page
*/
public function getHtmlOutput() {
if ( $this->getMathStyle() == MW_MATHSTYLE_DISPLAY ) {
$element = 'div';
} else {
$element = 'span';
}
$attribs = array();
if ( $this->getID() !== '' ) {
$attribs['id'] = $this->getID();
}
$output = HTML::openElement( $element, $attribs );
// MathML has to be wrapped into a div or span in order to be able to hide it.
// Remove displayStyle attributes set by the MathML converter
// (Beginning from Mathoid 0.2.5 block is the default layout.)
$mml = preg_replace( '/(<math[^>]*)(display|mode)=["\'](inline|block)["\']/', '$1', $this->getMathml() );
if ( $this->getMathStyle() == MW_MATHSTYLE_DISPLAY ) {
$mml = preg_replace( '/<math/', '<math display="block"', $mml );
}
$output .= Xml::tags( $element, array( 'class' => $this->getClassName(), 'style' => 'display: none;' ), $mml );
$output .= $this->getFallbackImage( $this->getMode() ) . "\n";
// TODO: Implement PNG image fallbacks without loading images in
// browsers that support MathML or SVG!
// $output .= $this->getFallbackImage( MW_MATH_PNG ) . "\n";
$output .= HTML::closeElement( $element );
return $output;
}
protected function dbOutArray() {
$out = parent::dbOutArray();
if ($this->getMathTableName() == 'mathoid' ) {
$out['math_input'] = $out['math_inputtex'];
unset($out['math_inputtex']);
}
return $out;
}
protected function dbInArray() {
$out = parent::dbInArray();
if ($this->getMathTableName() == 'mathoid' ) {
$out = array_diff( $out, array( 'math_inputtex' ) );
$out[] = 'math_input';
}
return $out;
}
protected function initializeFromDatabaseRow( $rpage ) {
// mathoid allows different input formats
// therefore the column name math_inputtex was changed to math_input
if ( $this->getMathTableName() == 'mathoid' && ! empty( $rpage->math_input ) ) {
$this->userInputTex = $rpage->math_input;
}
parent::initializeFromDatabaseRow( $rpage );
}
}