It does so by adding a floating black table (seen to the right) that you can use to log different errors and data points throughout your code. It makes debugging a cinch, and it helps you figure out what you’re doing wrong in a much more visible manner than adding alerts.

Blackbird is installed by adding a link in your page to some lightweight, downloadable JavaScript and CSS. Open the pop-up logging window using the F2 key. Other F2 variations will move the window, make it larger and close it.

The developers of blackbird promise you’ll never use alert() again. Check out the Blackbird webpage for code and live examples of the coding box and the kind of messages you can install in your page.

This isn’t a replacement for other debugging tools, like Firebug. However, unlike Firebug and like HTML design debugging tool XRAY or Firebug Lite, it works over any modern browser without a software installation.

See Also

• Webmonkey Tutorial: JavaScript Debugging for Beginners
• Debug JavaScript With Venkman
• Firebug Lite: Debugging Tools That Work in Any Browser
• Dragonfly: Opera Releases Free Developer Tools

Django developer Rob Hudson has built an extensible Django Debug Toolbar for viewing common information, such as HTTP headers and SQL queries. When installed and enabled, the toolbar takes up less than thirty pixels at the top of the screen. You can click one of the panels (there are currently seven available) and an overlay opens for that panel.

The inspiration came from the Symfony Project, a PHP framework. Hudson announced his project after Cal Henderson showed something similar for Pownce at DjangoCon during Henderson’s Why I Hate Django talk. Later, Hudson collaborated with fellow developer David Cramer, so the toolbar grew out of the Django community.

One of the coolest things about the project is that each panel is separate. So, if you don’t want the one that shows the current version, you don’t have to include it. Even better, if it’s missing functionality you want, or there’s something specific to your project you want to show in the debug toolbar, you can write your own panel.

Unlike many of the toolbars we see, this one is not installed in the browser. It resides on the same server as your Django installation. It’s meant for developers, not end-users, so it only shows when it matches the IP addresses added to the INTERNAL_IPS Django setting.

[Screenshot by David Cramer]

See also:

• DjangoCon Video Coverage Now Online
• Django Deemed Perfect, Goes 1.0
• Tutorial: Get Started With Django