Tracking newly added nodes in DOM using MutationObserver API

mutation_observer.js

function observeNewsletterCCT() {
	var target = $('.footer-newsletter:last')[0];
	var config = {
		childList: true, 
		subtree: true
	};
	var closeMsgBtn = '[data-action="close-message"]:first';
	var headerLogo = $('.header-logo');

	$.fn.observer = new MutationObserver(function(mutations) {
		mutations.forEach(function(mutation) {
			var newNodes = mutation.addedNodes;
			
			if (newNodes.length) {
				var $nodes = $(newNodes);

				$nodes.each(function() {
					var $node = $(this);

					if ($node.data('validation-error')) {
						$('.footer-newsletter .newsletter-alert-placeholder:first').empty();
						
						var input = $('.footer-newsletter .fields-group-form-control:first');
						input.find('p').remove();
						input.append($node);
						
						$.fn.fullpage.fitToSection();
					} else if ($node.hasClass('global-views-message-warning') || 
							       $node.hasClass('global-views-message-success')) {
						$('.footer-newsletter .fields-group-form-control p:first').remove();
						$('.footer-newsletter .newsletter-alert-placeholder:first').empty().append($node);
						
						$.fn.fullpage.fitToSection();
					}
				});
			}
		});
	});
	
	$.fn.observer.observe(target, config);

	$('body').on('click', closeMsgBtn, function () {			
		setTimeout(function() {
			$.fn.fullpage.fitToSection();
		}, 1);
	});
	
	headerLogo.click(function() {
		$.fn.fullpage.moveTo(1, 0);

		return false;
	});

	Backbone.history.once('route', function(router, name, args) {
		$('body').off('click', closeMsgBtn);
		headerLogo.off('click');
		
		$.fn.observer.disconnect();
	});
}