I encountered this weird situation last week: while testing ColdFusion code from a previous decade, I would see the output of part of the screen twice. Just like that – I had not changed a thing to the logic of the code, just cleaned up a bit of what I consider to be “bad” formatting in code written by others a long, long time ago (2005 or so).
I spent hours of debugging the code, even invited a few colleagues to help me – and then suddenly it struck me: CFML may look like XML, but it isn’t XML. Some CFML tags do their thing a second time when the tag is explicitly closed. One of those tag is <cfmodule>. I never use it myself – I prefer components and functions. But the code under scrutiny included a <cfmodule template='whatever.cfm >, and to “clean things up” I had added a slash at the end, like this: <cfmodule template='whatever.cfm />. Hence the double execution. So don’t do that, will you? Avoid closing <cfmodule>!
You can imagine my state of mind when I realised my error, don’t you? Yeah… I had seen this problem before, but much too long ago to actively avoid it in practice.
Before lecturing me on the subject: I know, I should be writing cfscript… but I don’t have the luxury to rewrite code that is more than 10 years old. So it will stay as it is.
Also: I consider this to be a bug in Adobe ColdFusion (at least in versions 6, 8 and 11). There’s no logical reason for such behaviour. I don’t know if Lucee or BlueDragon act similarly, but I hope they’re smarter than that!
And for the record: for me, code is “badly” formatted when it is hard to read – by me. I know compilers and computers have no trouble handling things like whole programs on a single line, or lacking coherent indents (unless it’s Python, of course), or unclosed XML tags (elements), to name but a few examples. I want code to easily readable by humans, and certainly by me – especially if I’m responsible for its maintenance…
