I've rewritten some of the block code to make it easier to create flexible styles with CSS. This code is useful if your theme supports it, but breaks older themes badly.
What is the best way to switch between two bodies of code in this case. I'm thinking that a $css_blocks flag in the compatible theme's config.php file that defaults to false if not present is a good start. But then how do you select an entire directory of code based on this flag, and how does that affect things when you change between a theme with this flag set and another without it?
I'm new to PHP and I have no idea how to go about such a thing and what the possible problems are, has anyone else done something like this before?