mediawiki-extensions-Math/MathMathML.php
physikerwelt 0f8f9cff93 Use Restbase rendering in MathML mode
* For tex input, the only form of Math input that
  is accepted on WMF wikis, we retrieve MathML and SVG
  image from Restbase without using the database cache.

Change-Id: Ief1b6345c17db41f92684e00233d57240e97599f
2015-12-04 17:27:40 +00:00

529 lines
15 KiB
PHP

<?php
/**
* MediaWiki math extension
*
* (c) 2002-2015 various MediaWiki contributors
* GPLv2 license; info in main package.
*/
use MediaWiki\Logger\LoggerFactory;
/**
* Converts LaTeX to MathML using the mathoid-server
*/
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';
private $svgPath = false;
/**
* @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( '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 ) {
if ( $this->inputType == 'tex' ) {
$tex = $this->getTex();
$displaystyle = false;
if ( $this->getMathStyle() == 'inlineDisplaystyle' ) {
// default preserve the (broken) layout as it was
$tex = '{\\displaystyle ' . $tex . '}';
} elseif ( $this->getMathStyle() !== 'inline' ) {
$displaystyle = true;
}
$rbi = new MathRestbaseInterface( $tex, $displaystyle );
$rbi->checkTeX();
$this->mathml = $rbi->getMathML();
$this->svg = $rbi->getSvg();
$this->svgPath = $rbi->getFullSvgUrl();
return $rbi->getSuccess();
}
if ( $forceReRendering ) {
$this->setPurge( true );
}
if ( $this->renderingRequired() ) {
return $this->doRender();
}
return true;
}
/**
* Helper function to checks if the math tag must be rendered.
* @return boolean
*/
private function renderingRequired() {
$logger = LoggerFactory::getInstance( 'Math' );
if ( $this->isPurge() ) {
$logger->debug( 'Rerendering was requested.' );
return true;
} else {
$dbres = $this->isInDatabase();
if ( $dbres ) {
if ( $this->isValidMathML( $this->getMathml() ) ) {
$logger->debug( 'Valid MathML entry found in database.' );
if ( $this->getSvg( 'cached' ) ) {
$logger->debug( 'SVG-fallback found in database.' );
return false;
} else {
$logger->debug( 'SVG-fallback missing.' );
return true;
}
} else {
$logger->debug( 'Malformatted entry found in database' );
return true;
}
} else {
$logger->debug( '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;
$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 $req Status the request status */
$status = $req->execute();
if ( $status->isGood() ) {
$res = $req->getContent();
return true;
} else {
if ( $status->hasMessage( 'http-timed-out' ) ) {
$error = $this->getError( 'math_timeout', $this->getModeStr(), $host );
$res = false;
LoggerFactory::getInstance( 'Math' )->warning( 'Timeout:' . var_export( array(
'post' => $post,
'host' => $host,
'timeout' => $wgMathLaTeXMLTimeout
), true ) );
} else {
// for any other unkonwn http error
$errormsg = $status->getHtml();
$error =
$this->getError( 'math_invalidresponse', $this->getModeStr(), $host, $errormsg,
$this->getModeStr( 'mathml' ) );
LoggerFactory::getInstance( 'Math' )->warning( 'NoResponse:' . var_export( array(
'post' => $post,
'host' => $host,
'errormsg' => $errormsg
), true ) );
}
return false;
}
}
/**
* Return a MathML daemon host.
*
* If more than one demon is available, one is chosen at random.
*
* @return string
*/
protected function pickHost() {
if ( is_array( $this->hosts ) ) {
$host = array_rand( $this->hosts );
$this->hosts = $host; // Use the same host for this class instance
} else {
$host = $this->hosts;
}
LoggerFactory::getInstance( 'Math' )->debug( '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() == 'latexml' && $this->getMathml() ) {
$out = 'type=mml&q=' . rawurlencode( $this->getMathml() );
} elseif ( $this->inputType == 'ascii' ) {
$out = 'type=asciimath&q=' . rawurlencode( $input );
} else {
throw new MWException( 'Internal error: Restbase should be used for tex rendering' );
}
LoggerFactory::getInstance( 'Math' )->debug( 'Get post data: ' . $out );
return $out;
}
/**
* Does the actual web request to convert TeX to MathML.
* @return boolean
*/
protected function doRender() {
if ( $this->getTex() === '' ) {
LoggerFactory::getInstance( 'Math' )->debug(
'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 ) {
return $this->processJsonResult( $jsonResult, $host );
} 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 );
LoggerFactory::getInstance( 'Math' )->warning(
'Mathoid conversion error:' . var_export( array(
'post' => $post,
'host' => $host,
'result' => $res
), true ) );
return false;
}
} else {
$this->lastError = $this->getError( 'math_invalidjson', $host );
LoggerFactory::getInstance( 'Math' )->error(
'MathML InvalidJSON:' . var_export( array(
'post' => $post,
'host' => $host,
'res' => $res
), true ) );
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;
}
$xmlObject = new XmlTypeCheck( $XML, null, false );
if ( !$xmlObject->wellFormed ) {
LoggerFactory::getInstance( 'Math' )->error(
'XML validation error: ' . var_export( $XML, true ) );
} 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 {
LoggerFactory::getInstance( 'Math' )->error( "Got wrong root element : $name" );
}
}
return $out;
}
/**
* @param boolean $noRender
* @return type
*/
private function getFallbackImageUrl( $noRender = false ) {
if ( $this->svgPath ) {
return $this->svgPath;
}
return SpecialPage::getTitleFor( 'MathShowImage' )->getLocalURL( array(
'hash' => $this->getMd5(),
'mode' => $this->getMode(),
'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() === 'display' ) {
// TODO: Improve style cleaning
$style = preg_replace(
'/margin\-(left|right)\:\s*\d+(\%|in|cm|mm|em|ex|pt|pc|px)\;/', '', $style
);
}
$style = preg_replace( '/position:\s*absolute;\s*left:\s*0px;/', '', $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 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
*/
private function getFallbackImage( $noRender = false, $classOverride = false ) {
$url = $this->getFallbackImageUrl( $noRender );
$attribs = array();
if ( $classOverride === false ) { // $class = '' suppresses class attribute
$class = $this->getClassName( true );
} else {
$class = $classOverride;
}
// TODO: move the common styles to the global stylesheet!
$style = 'background-image: url(\''. $url .
'\'); background-repeat: no-repeat; background-size: 100% 100%;';
$this->correctSvgStyle( $this->getSvg(), $style );
if ( $class ) {
$attribs['class'] = $class;
}
// Don't use an empty span, as that is going to be stripped by HTML tidy
// when enabled (which is true in production).
return Xml::element( 'meta', $this->getAttributes(
'span', $attribs, array( 'aria-hidden' => 'true', 'style' => $style
) ) );
}
protected function getMathTableName() {
return 'mathoid';
}
/**
* Calculates the default class name for a math element
* @param boolean $fallback
* @return string the class name
*/
private function getClassName( $fallback = false ) {
$class = 'mwe-math-';
if ( $fallback ) {
$class .= 'fallback-image-';
} else {
$class .= 'mathml-';
}
if ( $this->getMathStyle() == 'display' ) {
$class .= 'display';
} else {
$class .= 'inline';
}
if ( !$fallback ) {
// @codingStandardsIgnoreStart
$class .= ' mwe-math-mathml-a11y';
// @codingStandardsIgnoreEnd
}
return $class;
}
/**
* @return string Html output that is embedded in the page
*/
public function getHtmlOutput() {
if ( $this->getMathStyle() == '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() == 'display' ) {
$mml = preg_replace( '/<math/', '<math display="block"', $mml );
}
$output .= Xml::tags( $element, array(
'class' => $this->getClassName(), 'style' => 'display: none;'
), $mml );
$output .= $this->getFallbackImage();
$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 );
}
/**
* @param $jsonResult
* @param $host
*
* @return bool
*/
private function processJsonResult( $jsonResult, $host ) {
if ( $this->getMode() == 'latexml' || $this->inputType == 'pmml' ||
$this->isValidMathML( $jsonResult->mml )
) {
if ( isset( $jsonResult->svg ) ) {
$xmlObject = new XmlTypeCheck( $jsonResult->svg, null, false );
if ( !$xmlObject->wellFormed ) {
$this->lastError = $this->getError( 'math_invalidxml', $host );
return false;
} else {
$this->setSvg( $jsonResult->svg );
}
} else {
LoggerFactory::getInstance( 'Math' )->error(
'Missing SVG property in JSON result.' );
}
if ( $this->getMode() != 'latexml' && $this->inputType != 'pmml' ) {
$this->setMathml( $jsonResult->mml );
}
Hooks::run( 'MathRenderingResultRetrieved',
array( &$this,
&$jsonResult ) ); // Enables debugging of server results
return true;
} else {
$this->lastError = $this->getError( 'math_unknown_error', $host );
return false;
}
}
}