fa20-bt/plugin/math/math.js

95 lines
2.1 KiB
JavaScript
Executable File

/**
* A plugin which enables rendering of math equations inside
* of reveal.js slides. Essentially a thin wrapper for MathJax.
*
* @author Hakim El Hattab
*/
var RevealMath = window.RevealMath || (function(){
var options = Reveal.getConfig().math || {};
var mathjax = options.mathjax || 'https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.0/MathJax.js';
var config = options.config || 'TeX-AMS_HTML-full';
var url = mathjax + '?config=' + config;
var defaultOptions = {
messageStyle: 'none',
tex2jax: {
inlineMath: [ [ '$', '$' ], [ '\\(', '\\)' ] ],
skipTags: [ 'script', 'noscript', 'style', 'textarea', 'pre' ]
},
skipStartupTypeset: true
};
function defaults( options, defaultOptions ) {
for ( var i in defaultOptions ) {
if ( !options.hasOwnProperty( i ) ) {
options[i] = defaultOptions[i];
}
}
}
function loadScript( url, callback ) {
var head = document.querySelector( 'head' );
var script = document.createElement( 'script' );
script.type = 'text/javascript';
script.src = url;
// Wrapper for callback to make sure it only fires once
var finish = function() {
if( typeof callback === 'function' ) {
callback.call();
callback = null;
}
}
script.onload = finish;
// IE
script.onreadystatechange = function() {
if ( this.readyState === 'loaded' ) {
finish();
}
}
// Normal browsers
head.appendChild( script );
}
return {
init: function() {
defaults( options, defaultOptions );
defaults( options.tex2jax, defaultOptions.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 ] );
MathJax.Hub.Queue( Reveal.layout );
// Reprocess equations in slides when they turn visible
Reveal.addEventListener( 'slidechanged', function( event ) {
MathJax.Hub.Queue( [ 'Typeset', MathJax.Hub, event.currentSlide ] );
} );
} );
return Promise.resolve();
}
}
})();
Reveal.registerPlugin( 'math', RevealMath );