text: /*\
  title: $:/plugins/tiddlywiki/katex/wrapper.js
  type: application/javascript
  module-type: widget
  
  Wrapper for `katex.min.js` that provides a `<$latex>` widget. It is also available under the alias `<$katex>`
  
  \*/
  (function(){
  
  /*jslint node: true, browser: true */
  /*global $tw: false */
  "use strict";
  
  var katex = require("$:/plugins/tiddlywiki/katex/katex.min.js"),
  	Widget = require("$:/core/modules/widgets/widget.js").widget;
  
  var KaTeXWidget = function(parseTreeNode,options) {
  	this.initialise(parseTreeNode,options);
  };
  
  /*
  Inherit from the base widget class
  */
  KaTeXWidget.prototype = new Widget();
  
  /*
  Render this widget into the DOM
  */
  KaTeXWidget.prototype.render = function(parent,nextSibling) {
  	// Housekeeping
  	this.parentDomNode = parent;
  	this.computeAttributes();
  	this.execute();
  	// Get the source text
  	var text = this.getAttribute("text",this.parseTreeNode.text || "");
  	// Render it into a span
  	var span = this.document.createElement("span"),
  		options = {throwOnError: false};
  	try {
  		if(!this.document.isTiddlyWikiFakeDom) {
  			katex.render(text,span,options);
  		} else {
  			span.innerHTML = katex.renderToString(text,options);
  		}
  	} catch(ex) {
  		span.className = "tc-error";
  		span.textContent = ex;
  	}
  	// Insert it into the DOM
  	parent.insertBefore(span,nextSibling);
  	this.domNodes.push(span);
  };
  
  /*
  Compute the internal state of the widget
  */
  KaTeXWidget.prototype.execute = function() {
  	// Nothing to do for a katex widget
  };
  
  /*
  Selectively refreshes the widget if needed. Returns true if the widget or any of its children needed re-rendering
  */
  KaTeXWidget.prototype.refresh = function(changedTiddlers) {
  	var changedAttributes = this.computeAttributes();
  	if(changedAttributes.text) {
  		this.refreshSelf();
  		return true;
  	} else {
  		return false;	
  	}
  };
  
  exports.latex = KaTeXWidget;
  exports.katex = KaTeXWidget;
  
  })();
  
  