Listing elements of a Firebase node to a page

events.js

(function (window) {
	'use strict';

	var FirebaseRef = new window.Firebase("firebase-url-here"),
		document = window.document;

	FirebaseRef.on("value", function (eventsSnapshot) {
		var events = eventsSnapshot.val(),
			eventsListed = {},
			eventsDateSorted = [],
			eventsDateSortedIterator = 0,
			eventsDateSortedLength = 0,
			currentEvent,
			event,
			eventDate;

		// Put each event listing in the Events Firebase Node to an array keyed with event's timestamp (for sorting)
		for (event in events) {
			currentEvent = events[event];
			if (events.hasOwnProperty(event) && currentEvent.date !== undefined) {
				// If there is already an event with same key (timestamps are used as keys), increase
				// the timestamp by 1.
				if (eventsListed.hasOwnProperty(currentEvent.date.starts)) {
					eventsListed[currentEvent.date.starts + 1] = currentEvent;
				} else {
					eventsListed[currentEvent.date.starts] = currentEvent;
				}
			}
		}
		// Sort events, oldest event being the first, 
		eventsDateSorted = Object.keys(eventsListed).sort(function (a, b) {
			return a - b;
		});

		// List the sorted events
		// Cache the length of eventsDateSorted array (performance)
		for (eventsDateSortedLength = eventsDateSorted.length;
				eventsDateSortedIterator < eventsDateSortedLength;
				eventsDateSortedIterator + 1) {
			event = eventsListed[eventsDateSorted[eventsDateSortedIterator]];
			eventDate = new Date(event.date.starts);
			var trNode = document.createElement("tr"),
				tdNameNode = document.createElement("td"),
				tdNameTextNode = document.createTextNode(event.name),
				tdDateNode = document.createElement("td"),
				tdDateTextNode = document.createTextNode(eventDate.toLocaleString()),
				tdLocationNode = document.createElement("td"),
				tdLocationTextNode = document.createTextNode(event.location.name),
				tdTypeNode = document.createElement("td"),
				tdTypeTextNode = document.createTextNode(event.types && typeof event.types === "object" ? event.types.join(", ") : " ");
			
			// Construct the DOM Node Tree
			tdNameNode.appendChild(tdNameTextNode);
			tdDateNode.appendChild(tdDateTextNode);
			tdLocationNode.appendChild(tdLocationTextNode);
			tdTypeNode.appendChild(tdTypeTextNode);
			trNode.appendChild(tdNameNode);
			trNode.appendChild(tdDateNode);
			trNode.appendChild(tdLocationNode);
			trNode.appendChild(tdTypeNode);
			document.getElementById("eventsList").appendChild(trNode);
		}
	});
}(window));