Added template loading through AJAX

public_html/js/Util.js

@@ -0,0 +1,56 @@
+var App = App || {};
+
+App.Util = (function(jQuery) {
+
+	var templateCache = {};
+
+	function loadTemplate(templateName) {
+		return loadTemplateFromCache(templateName)
+			|| loadTemplateFromDOM(templateName)
+			|| loadTemplateWithAJAX(templateName);
+	}
+
+	function loadTemplateFromCache(templateName) {
+		if (templateName in templateCache) {
+			return new Promise(function(resolve, reject) {
+				resolve(templateCache[templateName]);
+			});
+		}
+	}
+
+	function loadTemplateFromDOM(templateName) {
+		var $template = jQuery('#' + templateName + '-template');
+		if ($template.length) {
+			return new Promise(function(resolve, reject) {
+				resolve($template.html());
+			});
+		}
+		return null;
+	}
+
+	function loadTemplateWithAJAX(templateName) {
+		return new Promise(function(resolve, reject) {
+			var templatesDir = '/templates';
+			var templateUrl = templatesDir + '/' + templateName + '.tpl';
+			var templateString;
+
+			$.ajax({
+				url: templateUrl,
+				method: 'GET',
+				success: function(data, textStatus, xhr) {
+					resolve(data);
+				},
+				error: function(xhr, textStatus, errorThrown) {
+					console.log(Error('Error while loading template ' +  templateName + ': ' + errorThrown));
+					reject();
+				},
+			});
+		});
+	}
+
+	return {
+		loadTemplate: loadTemplate,
+	};
+});
+
+App.DI.registerSingleton('util', App.Util);