Event delegation is especially useful in effects like dropdown menus, where lots of events on links may take place that can easily be handled at the root level (an <ol> or <ul> in this case).

There used to be one problem, though: although event delegation works fine for the mouse events, it does not work for the focus and blur events we need to make dropdown menus keyboard-accessible.

In the course of my ongoing event research, however, I found a way to delegate the focus and blur events, too. Maybe one of those frightfully clever JavaScript library authors will use this technique to shave off a few milliseconds of computing time

For all I know they're already aware of this technique; but it was new to me so I publish it anyway.

The presentation went well; I talked about the principles of unobtrusive JavaScript and it turned out that this concept was new to many attendees. I hope to have made a difference somewhere.

Testing event support is really awesomely complicated. I've been working steadily for two weeks now, and I still find new bugs and oddities daily, and twice on Sundays.

In any case, I discovered something remarkable when I studied the mousemove event. It sheds light on the way browser vendors keep track of each other's implementations nowadays, and on things that can go wrong.

Furthermore I've taken the opportunity to present the CSS compatibility table better. I split the page into two tables, CSS 2.1 and CSS 3, and I added a few CSS tests. The table below shows the new tests and their browser compatibility.

Update: Added Safari 3.1 Windows information to the main CSS table only.

Finally, a question. Who knows of CSS 3 declarations that don't yet figure in the CSS table but are supported by at least one browser? (Nightlies don't count, but betas do.) Please leave a comment with declaration name and supporting browser. It'll help me get my testing priorities straight.

There's a lot to be said about its CSS and JavaScript support, and I'm going to say it all. My readers, as well as the IE team, expect that.

Hope to see you there.

That's no coincidence. This specification contains definitions for many properties (and a few methods) that browsers have already been supporting for ages (such as offsetWidth), and W3C has paid scrupulous attention to the current implementation. No more theorizing into the blue — just check what browsers do and describe it in the specification. Excellent idea.

This blog entry talks about the crucial elementFromPoint method, and gives a few suggestions for improving the specification.