Archive for July, 2009

Firebug Console: Best (Cross-Browser) Practices

The Firebug plug-in is an essential and unparalleled tool for (web) UI development.  If you’re not using it, you should be.  But in any case, some of its features can make a lazy (or busy) programmer cause serious problems in other browsers (unless Firebug Lite is installed).

Over the past few years I’ve tried a number of approaches for ensuring that my Firebug console calls don’t cause errors on browsers which either don’t support it or don’t have Firebug installed.  A few approaches I’ve used myself are described here.

1. Checking for existence of the console before each call to it

if (typeof console!="undefined" && console.log){ console.log("blah blah"); }


if (typeof console!="undefined" && console.dir){ console.dir(someObject); }

While this is a safe way to avoid errors when the Firebug console is unavailable its pretty nasty since we don’t want this code repeated all over the place.

2. Creating dummy console methods when they are not available and using console freely

   if (!window.console||!console.firebug){
      var methods = [
         "log", "debug", "info", "warn", "error", "assert",
         "dir", "dirxml", "group", "groupEnd", "time", "timeEnd",
         "count", "trace", "profile", "profileEnd"
      window.console = {};
      for (var i=0; i<methods.length; i++){
         window.console[methods[i]] = function(){};


Firefox 3.5 Issues: Dark JPGs, XML parsing with JavaScript, etc.

posted by admin in Firebug, Firefox, JavaScript

I downloaded Firefox 3.5 last week and while I did notice a slight performance improvement, there are a few unexpected updates as well:

  • Photos look much darker in 3.5 since it uses the embedded ICC profile where other versions/browsers don’t.  Whether or not you think this the more correct method of displaying images, its a bug and has been acknowledged as such (
  • Firefox 3.5 seems more forgiving when processing XML with JavaScript.  Again, I’m going to test this more but it appears that no longer interprets empty text as a separate node.
  • Firefox 3.5 compatible version of Firebug is nearly useless.  Though, it is only in Beta and appears to be getting almost daily updates.


Recent Posts
Recent Comments
Simon: Hi there, i am looking for a parameter which can change direction of mov...
CM: Hi, Alex! I know exactly what king of messages you get, like "Hi, I'm new to php a...
admin: Alive and well....
SJ: If the array size exceeded 10 then sorting will not work. any help?...
shutterstock: I've learn several excellent stuff here. Definitely price bookmarking for revisiting....

Subchild is a blog about web development. It's author is Aleksandar Kolundzija, himself a web developer for 10++ years, presently a Hacker-in-Residence at betaworks. Prior to betaworks, Alex worked at Google, Meebo, MLB Advanced Media (, Razorfish, and elsewhere.

Some of Alex's side projects include, Slideshowify, LiveXmlEdit, and other blogs like Dopevector and When he's not working on any of those, Alex is probably playing guitar, producing music, mixing records, taking photos, playing with his kid, or watching documentaries about particle physics, the monetary system, etc.

Let him know what's up: ak @