Ajax Performance

iPhone developers are cranking

Greetings from Denver, where I’ll be until tomorrow evening for a wedding. With the trip, I haven’t had as much time to post, but I have enjoyed showing off my iPhone to my wife’s family. It definitely shows well.

I have been able to keep up with my reading, and as always there are a slew of iPhone development news items. First and foremost, Apple released their development documentation, a good sized collection of articles on device specific design and development information.

Building on top of personal experience and the help of this documentation, the development community continues to push ahead. And Joe Hewitt is among the leaders as always, recently releasing a native iPhone skin that puts web apps on a similar visual footing with native apps. This is achieved in part by using the WebKit CSS extension -webkit-border-image to lay out horizontally scalable buttons composed from a single image. This technique is covered in great detail in an article by Matthew Krivanek, where the performance benefit of the approach (fewer network round trips, our First Principle of Performance Optimization) is discussed.

Matthew’s example demonstrates 3 different buttons of different colors, but each is backed by a separate image. I wonder if you could expand on this image concatenation trick to place all 3 buttons in the same image (as discussed here) for even more EDGE round-trip avoidance.