Well, it's been about a week or so. i guess i better put up the moving report.
For the benefit of those sane enough not to read the rest of this blog, i was using a copy of b2 that i had *seriously* hacked to get things to work the way i wanted them to (things like auto-blocking, spam tagging (including a fun little tool that tagged potential spammers IPs so that it looked like their meaty comments were getting posted, but in fact they weren't), post-"posting" pingback flagging, and a bunch of other bits of joy). All of these were duct-taped and rubber banded into the code and worked well enough, but i knew full well that i really wanted to have something better.
As a bit more background for those that don't know me, i'm not a big advocate of using tech that's under the bleeding edge. i'll try it, use it myself and possibly contribute to it, but i'm not going to encourage others to do so until i view the program as being sufficiently useful. This is because i'm old enough to have been burned by previous packages that seemed slightly useful but required far more effort to actually become useful than simply using something else.
The Good
WordPress absolutely keeps to the original appeal. It's ready to go in 30 seconds or less. Edit a file, run the installer, log in and joy ensues. Plus, all data is stored in MySQL, which means that posts, comments and everything else is automatically available, and since MySQL can be more efficient about data storage than your OS can be, it also can save a fair amount of disk space.
It also has "plugins" which allow you to modify post content via optional functions using a darn spiffy technique. Granted, it'd be nice to be able to do those on a call-by-call basis, so if you wanted only one function out of a given library, but that's a minor thing and easily solved via your friend, Mr. vim (or Mr. emacs, depends on who wins the knife fight in the back alley).
Plus it's got lots of very nice management utilities, built in spam traps, and other wiz-bangery that make it rate rather high on the spiff-o-meter.
One other HUGE win for me is that they divided the styles between "admin" and "blog", meaning that there's no crossing the streams. In my old Franken-blog, things were a hair ugly since i kinda-sorta stomped on some of the styles in order to keep things tight. It goofed the admin section, but since i was the only one using it, i never complained or fixed it.
The Bad
Moving data between my old b2 install and WordPress wasn't nearly as fun-filled as i'd prefer. Granted, mostly that was my choice and decision, since i wanted to do a switch-over on my schedule. So it did mean building a bunch of PHP scripts to copy the data from the old tables into the new ones. Could i have done them as MySQL statements? Yeah, probably, but i was feeling lazy.
Because WordPress does multiple categories, there's now a separate "Categories" mapping table. Make sure you remember to map accordingly. Otherwise you get lots of head-desk poundy fun.
The other thing is that again, the "links" function is a required option which still takes more surgery than necessary to remove. Also, the Calendar is still broken. This was something i had to fix in b2 so i'm not really surprised, more annoyed, really. i'll probably make it a separate function block and might even release it into the wild.
The Stuff That The Kids Shouldn't Hear
Almost everything else was template or CSS related. Some of the functions are overtly helpful and do odd things, like not return a commentor's name or url, but display their comment text. Fortunately, WordPress defaults to fetching everything and returning them as objects, so it's damn easy to call the virtual method directly.
Most of what ate my time was delving into these sorts of issues, as well as figuring out why IE refused to display certain things. There are still a bunch of minor hacks i need to do, and frankly i'm concerned that future upgrades may stomp some of those changes, but i've been tagging and segregating things where i can, but i know i'm going to get stung by some of it.
Some of this would probably be alleviated by moving to Smarty, but again, PHP IS a templating language. Smarty is like using Perl to write a scripting language, sure, you can do it, but why?
Summary
Was it easy? No, but mostly it was self inflicted.
Was it worth it? Yep, youbetcha!
Would i recommend others to do it? If you've not monkeyed with your code, and have some time, definitely. If you have, be prepared for some goofiness, but that's what you get, and you knew it.
Hearty congrats to the WordPress team. They've definitely made a damn fine product.

