Logging From JavaScript

24. November, 2011

Logging is a recurring issue in JavaScript. There are a ┬ácouple of frameworks which support you. I’ve picked out two:

Some pros and cons:

log4javascript is very powerful. It contains lots of options, it has timers, several appenders (in page or using a popup window), the console supports tons of filters. If you know log4j, you’ll find almost everything replicated. If you need fewer options, there is even a lite version.

Despite the many options,┬álog4javascript is still simple to set up and use (so it’s not like log4j in every respect). The default setup needs 3 lines of code (not counting the script element to load the framework).

There are two minor points: The console is pretty big and the in-page version can’t be moved.

Blackbird is a really small logging framework. No frills, just the basics. So no exception logging, for example. A profiling option is the most complex feature. In the world of the logging frameworks, it’s the iPhone: Nice look and only the useful features. The console is always in page, it sits in one of the four browser corners, it can be hidden and shown with F2.

My main complaint about Blackbird is that you can’t use the mouse to move the console. Also disabling the framework needs several lines of code. A single variable would have been more comfortable.