TiddlyWiki5/editions/dev/tiddlers/javascript-widget-tutorial/hello-attribute-optimized.js

/*\

Hello, World widget

\*/
"use strict";

var Widget = require("$:/core/modules/widgets/widget.js").widget;

var MyWidget = function(parseTreeNode, options) {
	this.initialise(parseTreeNode, options);
};

/*
Inherit from the base widget class
*/
MyWidget.prototype = new Widget();

/*
Render this widget into the DOM
*/
MyWidget.prototype.render = function(parent, nextSibling) {
	this.parentDomNode = parent;
	this.computeAttributes();
	var message = this.getAttribute("message", "World");
	var textNode = this.document.createTextNode("Hello, " + message + "!");
	parent.insertBefore(textNode, nextSibling);
	this.domNodes.push(textNode);
};

/*
Refresh if the attribute value changed since render
*/
MyWidget.prototype.refresh = function(changedTiddlers) {
	// Find which attributes have changed
	var changedAttributes = this.computeAttributes();
	if(changedAttributes.message) {
		this.refreshSelf();
		return true;
	} else {
		return false;
	}
};

exports.hello = MyWidget;