Aleksandar • Vacić

iOS bits and pieces

Correct out of wrong

The guide I wrote on z-index positioning was linked on WaSP Buzz and was there spotted by the Safari developer, Dave Hyatt. Dave effectivelly overturned (what seemed like) 95% of my claims about standard compliance. Thanks to Axl who left a comment here I was able to quickly respond and update the guide accordingly.

After the whole thing settled down, it got me thinking on two issues…

First, Dave actually corrected only a fragment of the guide, but it was a very unfortunate place to make mistakes. I did it at the very first paragraph, overlooking the fact that non-auto z-index does not create stacking context. All my following conclusions and claims were drawn from that first paragraph. They were all correct when based on such basis. Since the basis was wrong, the entire guide turned-out wrong.

By simply changing the basis to correct information, I managed to update the entire 8-page guide in practically no time at all. I had grasped 95% of the concept correctly, so the re-typing went like a breeze.

Good thing was that essence of the guide, the examples, were correct from the beggining. Last three pages showed the right combination of z-indexes on both RPs and APs to get indentical rendering on all browsers. That was my intention from the start; I need to learn to refrain from the definitive sentences though.

This build-your-own-theory case reminded me of high-school classes about Lobachevsky geometry theory. Back then, most us had problems grasping it because we were first taught according to the old greek Euclid’s theory. Thus everything in the Lobachevsky universe seemed utterly wrong. But it was simply a question of habit; russian mathematician simply changed the basic axioms and build on top of that, thus everthing he did was entirely correct on this new basis.

Now I can completly understand that. There’s nothing better than hands-on learning. :)

Second…before I got linked on WaSP, I posted this on css-discuss and submitted it to css-vault, where it was quickly included. According to my site stats, the guide received quite a bit of visits after that, but no one said anything. Zoe echoed my own suspicions that something was wrong here, as it looked quite impossible that both gecko and khtml engines were wrong in exact the same way, while IE was right.

But when Chris Kaminski buzzed me on WaSP, unique visits for the guide tripled in a day and quality explanation came in a matter of hours. It’s the proof of both weight and influence that WaSP holds.