Firebug 1.6 is almost ready for release, and before it goes final I want a few more people to start using, playing with, and testing my extension to Firebug 1.6 called Illumination for Developers:
It makes Firebug know all about ExtJS. And it is very very handy, and so let's discuss a few of the features:
It presents ExtJS objects in a smarter way. It recognizes what they are and shows the whole name, like "Ext.DataView" instead of "Object" in the console and the other Firebug panels. And instead of random properties being appended, it looks for a ID-ish and a Value-ish property to show. This gives you an idea what you are looking at when you are debugging. See the example without and with Illumination:
Now, when you hover the mouse over the Ext.DataView above, it will highlight the component on the page. In the case above, the coder didn't give a descriptive itemId or name, so hovering over it does the trick -- it shows you exactly what that object is all about. This works for Ext Components and for Ext Elements. It even works for Ext Composite Elements -- it highlights all of its nodes on the page!
When you right click on an element in Firefox, Firebug adds an "Inspect Element" menu item to open Firebug and bring you to that element in the HTML panel. Illumination does the same sort of thing, but tries to find the best match: ideally some sort of UI widget, else an Ext Element.
There is a new panel added to Firebug called Illumination, and when you use the contextual menu above, this is where it brings you. The Illumination panel is the place to inspect ExtJS objects: Widgets (usually derived from Ext.Component, but not always), Data (Ext stores, records, fields), and Elements (Ext.Element and its brethren). These views show the hierarchical structure of your code:
It really takes some playing around with all of the above to get a feel of how useful and fun debugging can be again. Try this example page and look at the DataView, inspect the Store (use the side panel to see its records!), and generally browse around. Have fun!