From 47f530b355ce7c1a5199d5d7ea0afe8d3192c176 Mon Sep 17 00:00:00 2001
From: physikerwelt <wiki@physikerwelt.de>
Date: Fri, 29 Jan 2016 14:05:54 +0100
Subject: [PATCH] Support for chemical formulae

* Add support for LaTeX package mhchem.
* Add hook <ce>
* Add format <math chem>

See bug description for the details.

Bug: T98306
Change-Id: I2ab80834edc5d071618bc52f133cfb2b7ece5016
---
 Math.hooks.php                      | 15 +++++++++++++++
 MathMathML.php                      |  4 +++-
 MathRenderer.php                    |  4 ++++
 tests/MathRestBaseInterfaceTest.php |  9 +++++++++
 4 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/Math.hooks.php b/Math.hooks.php
index 895e785..bd2d07b 100644
--- a/Math.hooks.php
+++ b/Math.hooks.php
@@ -165,6 +165,7 @@ class MathHooks {
 	 */
 	static function onParserFirstCallInit( $parser ) {
 		$parser->setHook( 'math', array( 'MathHooks', 'mathTagHook' ) );
+		$parser->setHook( 'ce', array( 'MathHooks', 'ceTagHook' ) );
 
 		return true;
 	}
@@ -371,4 +372,18 @@ class MathHooks {
 		$wgMathDisableTexFilter = MathRenderer::getDisableTexFilter();
 		$wgDefaultUserOptions['math'] = self::mathModeToString( $wgDefaultUserOptions['math'] );
 	}
+
+	/**
+	 * Callback function for the <ce> parser hook.
+	 *
+	 * @param $content (the LaTeX input)
+	 * @param $attributes
+	 * @param Parser $parser
+	 * @return array
+	 */
+	static function ceTagHook( $content, $attributes, $parser ) {
+		$attributes['chem'] = true;
+		return MathHooks::mathTagHook( '\ce{' . $content . '}', $attributes, $parser );
+	}
+
 }
diff --git a/MathMathML.php b/MathMathML.php
index 515925e..d3fcec6 100644
--- a/MathMathML.php
+++ b/MathMathML.php
@@ -14,7 +14,7 @@ use MediaWiki\Logger\LoggerFactory;
 class MathMathML extends MathRenderer {
 
 	protected $defaultAllowedRootElements = array( 'math' );
-	protected $restbaseInputTypes = array( 'tex', 'inline-tex' );
+	protected $restbaseInputTypes = array( 'tex', 'inline-tex', 'chem' );
 	protected $allowedRootElements = '';
 	protected $hosts;
 
@@ -33,6 +33,8 @@ class MathMathML extends MathRenderer {
 				$this->setMathml( '<math>' . $tex . '</math>' );
 			} elseif ( $params['type'] == 'ascii' ) {
 				$this->inputType = 'ascii';
+			} elseif ( $params['type'] == 'chem' ){
+				$this->inputType = 'chem';
 			}
 		}
 		if ( !isset( $params['display'] ) && $this->getMathStyle() == 'inlineDisplaystyle' ) {
diff --git a/MathRenderer.php b/MathRenderer.php
index e61a5b3..4da750d 100644
--- a/MathRenderer.php
+++ b/MathRenderer.php
@@ -157,6 +157,10 @@ abstract class MathRenderer {
 				unset( $params['type'] );
 			}
 		}
+		if ( isset( $params['chem'] ) ) {
+			$mode = 'mathml';
+			$params['type'] = 'chem';
+		}
 		switch ( $mode ) {
 			case 'source':
 				$renderer = new MathSource( $tex, $params );
diff --git a/tests/MathRestBaseInterfaceTest.php b/tests/MathRestBaseInterfaceTest.php
index 9bab719..e78e6e3 100644
--- a/tests/MathRestBaseInterfaceTest.php
+++ b/tests/MathRestBaseInterfaceTest.php
@@ -54,6 +54,15 @@ class MathRestbaseInterfaceTest extends MediaWikiTestCase {
 		$this->assertEquals( 'Illegal TeX function', $rbi->getError()->error->message );
 	}
 
+	public function testChem() {
+		$input = '\ce{H2O}';
+		$rbi = new MathRestbaseInterface( $input, 'chem' );
+		$this->assertTrue( $rbi->checkTeX(), "Assuming that $input is valid input." );
+		$this->assertTrue( $rbi->getSuccess(), "Assuming that $input is valid input." );
+		$this->assertEquals( '{\ce {H2O}}', $rbi->getCheckedTex() );
+		$this->assertContains( '<msubsup>', $rbi->getMathML() );
+		$this->assertContains( '<mtext>H</mtext>', $rbi->getMathML() );
+	}
 	/**
 	 * @expectedException MWException
 	 * @expectedExceptionMessage TeX input is invalid.