application.js

var count = 1;

var showHelloWorld = function(count) {
	var resource = Template.call(this, count);
	var parser = new DOMParser();
	var doc = parser.parseFromString(resource, "application/xml");
	doc.addEventListener("select", function() {
		count += 1;
		var oldDoc = doc;
		var newDoc = showHelloWorld(count)
		navigationDocument.replaceDocument(newDoc, oldDoc);
	});	
  return doc;
};

App.onLaunch = function(options) {
	evaluateScripts([`http://localhost:9001/templates/hello_world.xml.js`],
		function(success) {
			var doc = showHelloWorld(count)
	    navigationDocument.pushDocument(doc);
		}
	);
};

hello_world.xml.js

var Template = function(count) { return `<?xml version="1.0" encoding="UTF-8" ?>
<document>
  <alertTemplate>
     <title>Hello World Example</title>
     <description>This is the Hello World ${count} description</description>
     <button>
        <text>Hit Me!</text>
     </button>
     <text>Hint: Try pressing the button</text>
  </alertTemplate>
</document>`
}