bookclub-advr

DSLC Advanced R Book Club
git clone https://git.eamoncaddigan.net/bookclub-advr.git
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mathjax3.js (2212B)

      1 /**
      2  * A plugin which enables rendering of math equations inside
      3  * of reveal.js slides. Essentially a thin wrapper for MathJax 3
      4  *
      5  * @author Hakim El Hattab
      6  * @author Gerhard Burger
      7  */
      8 export const MathJax3 = () => {
      9 
     10     // The reveal.js instance this plugin is attached to
     11     let deck;
     12 
     13     let defaultOptions = {
     14         tex: {
     15             inlineMath: [ [ '$', '$' ], [ '\\(', '\\)' ]  ]
     16         },
     17         options: {
     18             skipHtmlTags: [ 'script', 'noscript', 'style', 'textarea', 'pre' ]
     19         },
     20         startup: {
     21             ready: () => {
     22                 MathJax.startup.defaultReady();
     23                 MathJax.startup.promise.then(() => {
     24                     deck.layout();
     25                 });
     26             }
     27         }
     28     };
     29 
     30     function loadScript( url, callback ) {
     31 
     32         let script = document.createElement( 'script' );
     33         script.type = "text/javascript"
     34         script.id = "MathJax-script"
     35         script.src = url;
     36         script.async = true
     37 
     38         // Wrapper for callback to make sure it only fires once
     39         script.onload = () => {
     40             if (typeof callback === 'function') {
     41                 callback.call();
     42                 callback = null;
     43             }
     44         };
     45 
     46         document.head.appendChild( script );
     47 
     48     }
     49 
     50     return {
     51         id: 'mathjax3',
     52         init: function(reveal) {
     53 
     54             deck = reveal;
     55 
     56             let revealOptions = deck.getConfig().mathjax3 || {};
     57             let options = {...defaultOptions, ...revealOptions};
     58             options.tex = {...defaultOptions.tex, ...revealOptions.tex}
     59             options.options = {...defaultOptions.options, ...revealOptions.options}
     60             options.startup = {...defaultOptions.startup, ...revealOptions.startup}
     61 
     62             let url = options.mathjax || 'https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js';
     63             options.mathjax = null;
     64 
     65             window.MathJax = options;
     66 
     67             loadScript( url, function() {
     68                 // Reprocess equations in slides when they turn visible
     69                 deck.addEventListener( 'slidechanged', function( event ) {
     70                     MathJax.typeset();
     71                 } );
     72             } );
     73 
     74         }
     75     }
     76 
     77 };