mediawiki-extensions-Math/MathRenderer.php
Moritz Schubotz ff83048597 fix: texvccheck is not idempotent
The output of texvccheck is not only "checked" but also
rewritten to another form.
(For example $\R$ is transformed to $\mathbb{R}$.)
But the output might not be a valid input for the thexvccheck
part of texvc, like it happened in for the example given in the bug
description.
See also I599c4390da9b8f36d800f379a33ad5ce90f5096c
Bug: 61012
Change-Id: Iae5e350cb78c0e637e574390c586fbdb8dc38496
2014-02-07 10:27:21 +00:00

455 lines
12 KiB
PHP

<?php
/**
* MediaWiki math extension
*
* (c) 2002-2012 Tomasz Wegrzanowski, Brion Vibber, Moritz Schubotz, and other MediaWiki contributors
* GPLv2 license; info in main package.
*
* @file
*/
/**
* Abstract base class with static methods for rendering the <math> tags using
* different technologies. These static methods create a new instance of the
* extending classes and render the math tags based on the mode setting of the user.
* Furthermore this class handles the caching of the rendered output and provides
* debug information,
* if run in mathdebug mode.
*
* @author Tomasz Wegrzanowski
* @author Brion Vibber
* @author Moritz Schubotz
*/
abstract class MathRenderer {
/**
* The following variables should made private, as soon it can be verified
* that they are not being directly accessed by other extensions.
*/
protected $mode = MW_MATH_PNG;
protected $tex = '';
/** @var string the original user input string (which was used to caculate the inputhash) */
protected $userInputTex = '';
/**
* is calculated by texvc.
* @var string
*/
protected $hash = '';
protected $html = '';
protected $mathml = '';
protected $conservativeness = 0;
protected $params = '';
//STATE OF THE CLASS INSTANCE
/** @var boolean has variable tex been security-checked */
protected $texSecure = false;
protected $changed = false;
/**
* @var boolean forces rerendering if set to true
*/
protected $purge = false;
protected $recall;
protected $lastError = '';
/**
* Constructs a base MathRenderer
*
* @param string $tex (optional) LaTeX markup
* @param array $params (optional) HTML attributes
*/
public function __construct( $tex = '', $params = array() ) {
$this->userInputTex = $tex;
$this->tex = $tex;
$this->params = $params;
}
/**
* Static method for rendering math tag
*
* @param string $tex LaTeX markup
* @param array $params HTML attributes
* @param int $mode constant indicating rendering mode
* @return string HTML for math tag
*/
public static function renderMath( $tex, $params = array(), $mode = MW_MATH_PNG ) {
$renderer = self::getRenderer( $tex, $params, $mode );
return $renderer->render();
}
/**
* Static factory method for getting a renderer based on mode
*
* @param string $tex LaTeX markup
* @param array $params HTML attributes
* @param int $mode constant indicating rendering mode
* @return MathRenderer appropriate renderer for mode
*/
public static function getRenderer( $tex, $params = array(), $mode = MW_MATH_PNG ) {
global $wgDefaultUserOptions;
$validModes = array( MW_MATH_PNG, MW_MATH_SOURCE, MW_MATH_MATHJAX, MW_MATH_LATEXML );
if ( !in_array( $mode, $validModes ) )
$mode = $wgDefaultUserOptions['math'];
switch ( $mode ) {
case MW_MATH_MATHJAX:
case MW_MATH_SOURCE:
$renderer = new MathSource( $tex, $params );
break;
case MW_MATH_LATEXML:
$renderer = new MathLaTeXML( $tex, $params );
break;
case MW_MATH_PNG:
default:
$renderer = new MathTexvc( $tex, $params );
}
wfDebugLog ( "Math", 'start rendering $' . $renderer->tex . '$ in mode ' . $mode );
return $renderer;
}
/**
* Performs the rendering and returns the rendered element that needs to be embedded.
*
* @return string of rendered HTML
*/
abstract public function render();
/**
* texvc error messages
* TODO: update to MathML
* Returns an internationalized HTML error string
*
* @param string $msg message key for specific error
* @param Varargs $parameters (optional) zero or more message parameters for specific error
* @return string HTML error string
*/
public function getError( $msg /*, ... */ ) {
$mf = wfMessage( 'math_failure' )->inContentLanguage()->escaped();
$parameters = func_get_args();
array_shift( $parameters );
$errmsg = wfMessage( $msg, $parameters )->inContentLanguage()->escaped();
$source = htmlspecialchars( str_replace( "\n", ' ', $this->tex ) );
return "<strong class='error texerror'>$mf($errmsg): $source</strong>\n";
}
/**
* Return hash of input
*
* @return string hash
*/
public function getInputHash() {
// TODO: What happens if $tex is empty?
$dbr = wfGetDB( DB_SLAVE );
return $dbr->encodeBlob( pack( "H32", md5( $this->getUserInputTex() ) ) ); # Binary packed, not hex
}
/**
* Reads rendering data from database
*
* @return boolean true if read successfully, false otherwise
*/
public function readFromDatabase() {
wfProfileIn( __METHOD__ );
$dbr = wfGetDB( DB_SLAVE );
$rpage = $dbr->selectRow( 'math', $this->dbInArray(),
array( 'math_inputhash' => $this->getInputHash() ), __METHOD__ );
if ( $rpage !== false ) {
$this->initializeFromDatabaseRow( $rpage );
if ( ! is_callable( 'StringUtils::isUtf8' ) ) {
$msg = wfMessage( 'math_latexml_xmlversion' )->inContentLanguage()->escaped();
trigger_error( $msg, E_USER_NOTICE );
wfDebugLog( 'Math', $msg );
// If we can not check if mathml output is valid, we skip the test and assume that it is valid.
$this->recall = true;
wfProfileOut( __METHOD__ );
return true;
} elseif ( StringUtils::isUtf8( $this->mathml ) ) {
$this->recall = true;
wfProfileOut( __METHOD__ );
return true;
}
}
# Missing from the database and/or the render cache
$this->recall = false;
wfProfileOut( __METHOD__ );
return false;
}
/**
*
* @param database_row $rpage
*/
public function initializeFromDatabaseRow( $rpage ) {
$dbr = wfGetDB( DB_SLAVE );
$xhash = unpack( 'H32md5',
$dbr->decodeBlob( $rpage->math_outputhash ) . " " );
$this->hash = $xhash['md5'];
$this->conservativeness = $rpage->math_html_conservativeness;
$this->html = $rpage->math_html;
$this->mathml = utf8_decode( $rpage->math_mathml );
$this->storedInDatabase = true;
}
/**
* @return array with the database column names
*/
private function dbInArray() {
return array( 'math_inputhash', 'math_outputhash', 'math_html_conservativeness', 'math_html',
'math_mathml' );
}
/**
* Writes rendering entry to database.
*
* WARNING: Use writeCache() instead of this method to be sure that all
* renderer specific (such as squid caching) are taken into account.
* This function stores the values that are currently present in the class to the database even if they are empty.
*
* This function can be seen as protected function.
*/
public function writeToDatabase( $dbw = null ) {
# Now save it back to the DB:
if ( !wfReadOnly() ) {
$dbw = $dbw ?: wfGetDB( DB_MASTER );
wfDebugLog( "Math", 'store entry for $' . $this->tex . '$ in database (hash:' . bin2hex( $this->hash ) . ")\n" );
$outArray = $this->dbOutArray();
$dbw->onTransactionIdle(
function() use( $dbw, $outArray ) {
$dbw->replace( 'math', array( 'math_inputhash' ), $outArray, __METHOD__ );
} );
}
}
/**
* Gets an array that matches the variables of the class to the database columns
* @return array
*/
private function dbOutArray() {
global $wgDebugMath;
$dbr = wfGetDB( DB_SLAVE );
if ( $this->hash ) {
$outmd5_sql = $dbr->encodeBlob( pack( 'H32', $this->hash ) );
} else {
$outmd5_sql = 0; // field cannot be null
// TODO: Change Database layout to allow for null values
}
$out = array( 'math_inputhash' => $this->getInputHash(), 'math_outputhash' => $outmd5_sql,
'math_html_conservativeness' => $this->conservativeness, 'math_html' => $this->html,
'math_mathml' => utf8_encode( $this->mathml ) );
wfDebugLog( "Math", "Store Data:" . var_export( $out, true ) . "\n\n" );
return $out;
}
/**
* Returns sanitized attributes
*
* @param string $tag element name
* @param array $defaults default attributes
* @param array $overrides attributes to override defaults
* @return array HTML attributes
*/
protected function getAttributes( $tag, $defaults = array(), $overrides = array() ) {
$attribs = Sanitizer::validateTagAttributes( $this->params, $tag );
$attribs = Sanitizer::mergeAttributes( $defaults, $attribs );
$attribs = Sanitizer::mergeAttributes( $attribs, $overrides );
return $attribs;
}
/**
* Writes cache. Writes the database entry if values were changed
*/
public function writeCache() {
if ( $this->isChanged() ) {
$this->writeToDatabase();
}
}
/**
* Determines if this is a cached/recalled render
*
* @return boolean true if recalled, false otherwise
*/
public function isRecall() {
return $this->recall;
}
/**
* Gets TeX markup
*
* @return string TeX markup
*/
public function getTex() {
return $this->tex;
}
/**
* gets the rendering mode MW_MATH_*
*
* @return int
*/
public function getMode() {
return $this->mode;
}
/**
* Sets the TeX code
*
* @param string $tex
*/
public function setTex( $tex ) {
$this->changed = true;
$this->tex = $tex;
}
/**
* Get the hash calculated by texvc
*
* @return string hash
*/
public function getHash() {
return $this->hash;
}
/**
* @param string $hash
*/
public function setHash( $hash ) {
$this->changed = true;
$this->hash = $hash;
}
/**
* Returns the html-representation of the mathematical formula.
* @return string
*/
public function getHtml() {
return $this->html;
}
/**
* @param string $html
*/
public function setHtml( $html ) {
$this->changed = true;
$this->html = $html;
}
/**
* Gets the MathML XML element
* @return string in UTF-8 encoding
*/
public function getMathml() {
return $this->mathml;
}
/**
* @param string $mathml use UTF-8 encoding
*/
public function setMathml( $mathml ) {
$this->changed = true;
$this->mathml = $mathml;
}
/**
* Gets the so called 'conservativeness' calculated by texvc
*
* @return int
*/
public function getConservativeness() {
return $this->conservativeness;
}
/**
* @param int $conservativeness
*/
public function setConservativeness( $conservativeness ) {
$this->changed = true;
$this->conservativeness = $conservativeness;
}
/**
* Get the attributes of the math tag
*
* @return array()
*/
public function getParams() {
return $this->params;
}
/**
* @param array() $params
*/
public function setParams( $params ) {
// $changed is not set to true here, because the attributes do not affect
// the rendering in the current implementation.
// If this behavior will change in the future $this->tex is no longer a
// primary key and the input hash cannot be calculate form $this->tex
// only. See the discussion 'Tag extensions in Block mode' on wikitech-l.
$this->params = $params;
}
/**
* Checks if the instance was modified i.e., because math was rendered
*
* @return boolean true if something was changed false otherwise
*/
public function isChanged() {
return $this->changed;
}
/**
* Checks if there is an explicit user request to rerender the math-tag.
* @return boolean
*/
function isPurge( ) {
if ( $this->purge ) {
return true;
}
// TODO: Figure out if ?action=purge
// until this issue is resolved we use ?mathpurge=true instead
global $wgRequest;
return ( $wgRequest->getVal( 'mathpurge' ) === "true" );
}
/**
* Sets purge. If set to true the render is forced to rerender and must not
* use a cached version.
* @return boolean
*/
function setPurge( $purge = true ) {
$this->changed = true;
$this->purge = $purge;
}
function getLastError() {
return $this->lastError;
}
/**
* Get if the input tex was marked as secure
* @return boolean
*/
public function isTexSecure() {
return $this->texSecure;
}
public function checkTex() {
if ( !$this->texSecure ) {
$checker = new MathInputCheckTexvc( $this->userInputTex );
if ( $checker->isValid() ){
$this->setTex( $checker->getValidTex() );
$this->texSecure = true;
return true;
} else {
$this->lastError = $checker->getError();
return false;
}
}
}
/**
* @return string original tex string specified by the user
*/
public function getUserInputTex(){
return $this->userInputTex;
}
}