Update to last reveal.js 4.2.1 (#148)
diff --git a/inst/reveal.js-4.2.1/plugin/math/mathjax2.js b/inst/reveal.js-4.2.1/plugin/math/mathjax2.js
new file mode 100644
index 0000000..daebe7e
--- /dev/null
+++ b/inst/reveal.js-4.2.1/plugin/math/mathjax2.js
@@ -0,0 +1,89 @@
+/**
+ * A plugin which enables rendering of math equations inside
+ * of reveal.js slides. Essentially a thin wrapper for MathJax.
+ *
+ * @author Hakim El Hattab
+ */
+export const MathJax2 = () => {
+
+ // The reveal.js instance this plugin is attached to
+ let deck;
+
+ let defaultOptions = {
+ messageStyle: 'none',
+ tex2jax: {
+ inlineMath: [ [ '$', '$' ], [ '\\(', '\\)' ] ],
+ skipTags: [ 'script', 'noscript', 'style', 'textarea', 'pre' ]
+ },
+ skipStartupTypeset: true
+ };
+
+ function loadScript( url, callback ) {
+
+ let head = document.querySelector( 'head' );
+ let script = document.createElement( 'script' );
+ script.type = 'text/javascript';
+ script.src = url;
+
+ // Wrapper for callback to make sure it only fires once
+ let finish = () => {
+ if( typeof callback === 'function' ) {
+ callback.call();
+ callback = null;
+ }
+ }
+
+ script.onload = finish;
+
+ // IE
+ script.onreadystatechange = () => {
+ if ( this.readyState === 'loaded' ) {
+ finish();
+ }
+ }
+
+ // Normal browsers
+ head.appendChild( script );
+
+ }
+
+ return {
+ id: 'mathjax2',
+
+ init: function( reveal ) {
+
+ deck = reveal;
+
+ let revealOptions = deck.getConfig().mathjax2 || deck.getConfig().math || {};
+
+ let options = { ...defaultOptions, ...revealOptions };
+ let mathjax = options.mathjax || 'https://cdn.jsdelivr.net/npm/mathjax@2/MathJax.js';
+ let config = options.config || 'TeX-AMS_HTML-full';
+ let url = mathjax + '?config=' + config;
+
+ options.tex2jax = { ...defaultOptions.tex2jax, ...revealOptions.tex2jax };
+
+ options.mathjax = options.config = null;
+
+ loadScript( url, function() {
+
+ MathJax.Hub.Config( options );
+
+ // Typeset followed by an immediate reveal.js layout since
+ // the typesetting process could affect slide height
+ MathJax.Hub.Queue( [ 'Typeset', MathJax.Hub, deck.getRevealElement() ] );
+ MathJax.Hub.Queue( deck.layout );
+
+ // Reprocess equations in slides when they turn visible
+ deck.on( 'slidechanged', function( event ) {
+
+ MathJax.Hub.Queue( [ 'Typeset', MathJax.Hub, event.currentSlide ] );
+
+ } );
+
+ } );
+
+ }
+ }
+
+};