Christophe Dervieux | e1893ae | 2021-10-07 17:09:02 +0200 | [diff] [blame] | 1 | /** |
| 2 | * A plugin which enables rendering of math equations inside |
| 3 | * of reveal.js slides. Essentially a thin wrapper for MathJax. |
| 4 | * |
| 5 | * @author Hakim El Hattab |
| 6 | */ |
Christophe Dervieux | 8afae13 | 2021-12-06 15:16:42 +0100 | [diff] [blame] | 7 | export const MathJax2 = () => { |
Christophe Dervieux | e1893ae | 2021-10-07 17:09:02 +0200 | [diff] [blame] | 8 | |
| 9 | // The reveal.js instance this plugin is attached to |
| 10 | let deck; |
| 11 | |
| 12 | let defaultOptions = { |
| 13 | messageStyle: 'none', |
| 14 | tex2jax: { |
| 15 | inlineMath: [ [ '$', '$' ], [ '\\(', '\\)' ] ], |
| 16 | skipTags: [ 'script', 'noscript', 'style', 'textarea', 'pre' ] |
| 17 | }, |
| 18 | skipStartupTypeset: true |
| 19 | }; |
| 20 | |
| 21 | function loadScript( url, callback ) { |
| 22 | |
| 23 | let head = document.querySelector( 'head' ); |
| 24 | let script = document.createElement( 'script' ); |
| 25 | script.type = 'text/javascript'; |
| 26 | script.src = url; |
| 27 | |
| 28 | // Wrapper for callback to make sure it only fires once |
| 29 | let finish = () => { |
| 30 | if( typeof callback === 'function' ) { |
| 31 | callback.call(); |
| 32 | callback = null; |
| 33 | } |
| 34 | } |
| 35 | |
| 36 | script.onload = finish; |
| 37 | |
| 38 | // IE |
| 39 | script.onreadystatechange = () => { |
| 40 | if ( this.readyState === 'loaded' ) { |
| 41 | finish(); |
| 42 | } |
| 43 | } |
| 44 | |
| 45 | // Normal browsers |
| 46 | head.appendChild( script ); |
| 47 | |
| 48 | } |
| 49 | |
| 50 | return { |
Christophe Dervieux | 8afae13 | 2021-12-06 15:16:42 +0100 | [diff] [blame] | 51 | id: 'mathjax2', |
Christophe Dervieux | e1893ae | 2021-10-07 17:09:02 +0200 | [diff] [blame] | 52 | |
| 53 | init: function( reveal ) { |
| 54 | |
| 55 | deck = reveal; |
| 56 | |
Christophe Dervieux | 8afae13 | 2021-12-06 15:16:42 +0100 | [diff] [blame] | 57 | let revealOptions = deck.getConfig().mathjax2 || deck.getConfig().math || {}; |
Christophe Dervieux | e1893ae | 2021-10-07 17:09:02 +0200 | [diff] [blame] | 58 | |
| 59 | let options = { ...defaultOptions, ...revealOptions }; |
Christophe Dervieux | 8afae13 | 2021-12-06 15:16:42 +0100 | [diff] [blame] | 60 | let mathjax = options.mathjax || 'https://cdn.jsdelivr.net/npm/mathjax@2/MathJax.js'; |
Christophe Dervieux | e1893ae | 2021-10-07 17:09:02 +0200 | [diff] [blame] | 61 | let config = options.config || 'TeX-AMS_HTML-full'; |
| 62 | let url = mathjax + '?config=' + config; |
| 63 | |
| 64 | options.tex2jax = { ...defaultOptions.tex2jax, ...revealOptions.tex2jax }; |
| 65 | |
| 66 | options.mathjax = options.config = null; |
| 67 | |
| 68 | loadScript( url, function() { |
| 69 | |
| 70 | MathJax.Hub.Config( options ); |
| 71 | |
| 72 | // Typeset followed by an immediate reveal.js layout since |
| 73 | // the typesetting process could affect slide height |
| 74 | MathJax.Hub.Queue( [ 'Typeset', MathJax.Hub, deck.getRevealElement() ] ); |
| 75 | MathJax.Hub.Queue( deck.layout ); |
| 76 | |
| 77 | // Reprocess equations in slides when they turn visible |
| 78 | deck.on( 'slidechanged', function( event ) { |
| 79 | |
| 80 | MathJax.Hub.Queue( [ 'Typeset', MathJax.Hub, event.currentSlide ] ); |
| 81 | |
| 82 | } ); |
| 83 | |
| 84 | } ); |
| 85 | |
| 86 | } |
| 87 | } |
| 88 | |
| 89 | }; |