Friday March 17, 2006
Things Not To Do at 4 pm on Friday on the Internet
I'm not a full-time developer anymore, but I still know a few things.
- Don't ever deply new code on a production system after
- ... and never, ever do this on a Friday afternoon.
- Don't parse XML with regular expressions.
- Don't treat newlines as significant in XHTML, except within attribute
values, where the specification says not to use them.
- Don't double-encode text and markup.
- Don't add extra formatting to properly-formatted documents.
- Don't deploy new code without testing it first on actual data.
- Don't tell your users that they have to change the way they publish
information in your system because you just made a change on 4 pm on a Friday
afternoon that treats newlines as significant in XHTML though nothing else on
the Internet does so, tell your users to fix all of their existing data, and
then go home before they can say "Uh... that's broken. Why did you do
- Don't remove a feature that lets people who know what they're doing
disable all of this "helpful" magic and turn on the magic by default if it
changes their existing data.
- If you ignore everything else, don't claim "Oh, you can still write valid
XHTML. Just don't use paragraph tags and let the system put them in
I really don't have words for this except "BY DEFAULT?", "4 PM?!", and