codeblock as a widget and plugin for highlight code blocks

core/modules/widgets/codeblock.js

@@ -0,0 +1,64 @@
+/*\
+title: $:/core/modules/widgets/codeblock.js
+type: application/javascript
+module-type: widget
+
+Code block node widget
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+var Widget = require("$:/core/modules/widgets/widget.js").widget;
+
+var CodeBlockWidget = function(parseTreeNode,options) {
+	this.initialise(parseTreeNode,options);
+};
+
+/*
+Inherit from the base widget class
+*/
+CodeBlockWidget.prototype = new Widget();
+
+/*
+Render this widget into the DOM
+*/
+CodeBlockWidget.prototype.render = function(parent,nextSibling) {
+	this.parentDomNode = parent;
+	this.computeAttributes();
+	this.execute();
+	var codeNode = this.document.createElement("code");
+	if (this.getAttribute("language")) {
+		codeNode.setAttribute("class",this.getAttribute("language"));
+	}
+	var domNode = this.document.createElement("pre");
+	codeNode.appendChild(this.document.createTextNode(this.getAttribute("code")));
+	domNode.appendChild(codeNode);
+	parent.insertBefore(domNode,nextSibling);
+	this.domNodes.push(domNode);
+
+	if(this.postRender) {
+		this.postRender();
+	}
+};
+
+/*
+Compute the internal state of the widget
+*/
+CodeBlockWidget.prototype.execute = function() {
+	// Nothing to do for a text node
+};
+
+/*
+Selectively refreshes the widget if needed. Returns true if the widget or any of its children needed re-rendering
+*/
+CodeBlockWidget.prototype.refresh = function(changedTiddlers) {
+	return false;
+};
+
+exports.codeblock = CodeBlockWidget;
+
+})();