real world (X)HTML

Having been developing mostly in a bubble for a few year, I forgot that some people still use Internet Explorer for Windows. (Sheesh, get Firefox already.)

Turns out (thanks, Tantek!) that IE6 doesn’t support XHTML. That’s not usually too much of a problem, unless you try and make a previously non-empty tag, like <script> empty.

Well, IE6 sees that and dies. It stops parsing the page. So, people using IE6 saw a blank page instead of the RSVP page.

The fix is to go back to using <script>...</script> .

some lessons on usability

after i launched my house concerts site, i sent out emails with customized RSVP links to everyone.

the next day, i got a bug report that RSVPing “no” wasn’t working. well, it was — sort of. the problem was that even if you clicked “no,” you were still expected to enter the number of seats you wanted. the workaround, was, of course, to enter “1” seat and click no. but only one person figured that out. everyone else just gave up, including otherwise technically savvy folks who work for a computer company.

it’s long been known that poor usability is bad for e-commerce — Nielsen’s 2001 study showed a success rate of around 56% for purchases.

what i didn’t realize was just how much this stuff matters.

anyway, the bug is fixed, i email the five people who ran in to it, and three of them have re-visited the web site.

so, once again, usability matters. a lot.

date sorting code

i was making a birthday-tracking application, and wanted to be able to do year-insensitive date sorts. i couldn’t find what I was looking for, so I wrote this:

int personSortByBirthday (NSCalendarDate *d1, NSCalendarDate *d2, void *context) {
	int day1 = [d1 dayOfMonth];
	int day2 = [d2 dayOfMonth];
	int month1 = [d1 monthOfYear];
	int month2 = [d2 monthOfYear];
	
	if (month1 < month2) {
		return NSOrderedAscending;
	} else if (month1 > month2) {
		return NSOrderedDescending;
	} else {
		if (day1 < day2) {
			return NSOrderedAscending;
		} else if (day1 > day2) {
			return NSOrderedDescending;
		} else {
			return NSOrderedSame;
		}
	}       
}

canon lens guide

Adam Tow of COBA posted a good list of Canon lenses and notes Patrick Murphy’s comprehensive list and database.

for my nikon, i have a 50mm/f1.8, a 17-70/f4.5-5.5 and a sigma 70-300/f4-5.6. since i do a lot of concerts, what i really want is a 20-100/f 1.4. but i can’t imagine such a thing existing (or costing less than my camera). for compairson purposes, note the 28mm/f1.4 is $1700; the 35mm/f2 is only $300.