During the winter break, I mostly spent my time off, dealing with various family issues, including the death of my grandfather.

I also implemented adding an attribute to an element. This is significant because it is the first editing action which couldn’t be done inline. Other edits to date have been text node changes, or deleting a node — stuff that doesn’t require a lot of detail. A new attribute can have a namespace URI, a prefix, a local name and a value. That’s four different input fields.

DOM Inspector does this (thanks to bug 205872 and Shawn Wilsher) through a dialog. But I’ve long understood that, as I say in the Verbosio overview, “Dialogs are exceedingly annoying to the end-user.” To solve this, I came up with the idea of an inline <xul:precondition/> element binding. I had even written some mockup code in July 2006 to express how Verbosio should handle preconditions.

Mockup code is, naturally, not real-world code. Over the break, I realized the code was not workable and had to be scrapped. Good intent, presumably good UI, just not usable. A bit of rewriting, some debugging and a real-world application (adding attributes) later, and the code is now operational.

Next on my to-do list is a bit of code reorganization; I wrote a lot of code just for this Inspector-based feature which I expect I’ll be reusing in a more global setting for Verbosio (the XML template editor I talked about a few months ago). I’ll also be implementing the ability to insert new content into a XML document (something I know DOM-I doesn’t do right now). Both of these will be done via the precondition model.

Lastly, for several months I’ve been hunting for a book which describes best practices in user-interface design. It’s one thing to have technical references on UI elements. It’s something else entirely to know how to design a user-friendly UI. The Firefox UI team succeeded at this brilliantly and raised the standard for the rest of us! So I’ve been scratching my head trying to figure out what’s good and what’s bad in UI design, and there is an astonishing lack of written work about that.

Two days ago, I found “Designing Interfaces”, by Jenifer Tidwell. I think this book is exactly what I’ve been looking for – I’ve only gotten into it about three chapters, and it’s a fairly well-written guide. More importantly, it’s not a code-based guide. It guides readers towards sensible, useful user-interface layouts and the motivations behind them

. I think anyone doing lots of UI work should take a look at this book, and UI reviewers should probably read it too (though they may find they already know most of it).