Christian Heilmann

Posts Tagged ‘library’

YQL Geo Library and Introduction to Geo Hacking talk

Thursday, March 11th, 2010

I am right now in Atlanta, Georgia for the Georgia Tech University Hack and one of the hot technologies we want to have students hack on is geolocation. To this end, I have given a talk on geo hacking:

As a follow-up to the talk and to make it easier for students to build geo hacks rather than battling the different APIs, I’ve put together a small JavaScript library that fulfills a lot of geo hacking needs:

  • Detecting the visitor’s location with the W3C geo API and with IP as a fallback
  • Find geo location from text
  • Find location from lat/lon pair
  • Find locations in a certain web document (by URL)
  • Get the location for a certain IP number

Check out the YQL Geo Library demo page and get the YQL Geo Library source on GitHub.

The missing native DOM methods – according to my course attendees

Thursday, July 31st, 2008

During the course I am currently giving in Sunnyvale on basics of the DOM and progressive enhancement I asked the attendees which methods seem to be missing in the native DOM implementation and this is what we came up with:

  • createLink(url,text) – a shortcut method to create a link with a text node inside – something you constantly have to do when creating interfaces
  • insertAfter(newNode,oldNode) – there is an insertBefore, but no insertAfter
  • removeNode(node) – the native removeChild is convoluted
  • textElement(elementName,text) – it seems not necessary to create an Element, then create a text node and apply it, this could be one step
  • addScript(url) – to lazy-load JavaScripts
  • normalizeNode(node) – to remove those pesky line-breaks that interfere with nextSibling or previousSibling
  • getText(node) – retrieving the text content of a node that is either a text or an element node
  • setText(node,text) – setting the text regardless of node type

I asked the attendees to come up with a method each and to present them, here’s what we got:

jukuhelpers = function(){
function createLink(url,text,cssClass){
var link = document.createElement(‘a’);
if (typeof url = 'string'){
link.setAttribute('href', url);

if (typeof text = ‘string’){

if (typeof cssClass = 'string'){
link.className = cssClass;

return link;

function insertAfter(newNode,oldNode){
? oldNode.parentNode.insertBefore(newNode, oldNode.nextSibling)
: oldNode.parentNode.appendChild(newNode);

function removeNode(node){
if (node) {

function textElement(elementName,text){
if (typeof text = ‘string’){
var txtElement = document.createElement(elementName);
var txtNode = document.createTextNode(text);

return txtElement;

function addScript(url){
var s = document.createElement(‘script’);
s.setAttribute(‘type’, ‘text/javascript’);
s.setAttribute(‘src’, url);
var head = document.getElementsByTagName(‘head’)[0];

function getText(node){
var txt;
if (node && node.nodeType = 1) {
if (node.hasChildNodes()) {
txt = node.firstChild.nodeValue;

if (node && node.nodeType = 3) {
txt = node.nodeValue;

return txt;

function setText(node,text){
if (node && node.nodeType = 1) {
if (node.hasChildNodes()) {
node.firstChild.nodeValue = text;

else {

if (node && node.nodeType = 3) {
node.nodeValue = text;

function normalizeNode(node){
var spaceTest = /^s+$/;
var children = node.childNodes;
for(var i=0;children[i];i++){
if(children[i].nodeType === 3){





You can get the jukuhelpers.js file if you want to use it yourself.

Anything else that is missing or any bugs in this?