Writing $wp_rewrite->non_wp_rules to .htaccess?

I wonder if I should take the rewrite functionality out of the theme and build it ito an acompanying plugin? I’d prefer to keep it all in the theme though…

Hmm… can’t edit my own post to add this, so I thought I’d point out some interesting links. I still haven’t found a solution, but these have shed some light:

Adding rewrite rules and $wp_rewrite->flush_rules():
http://wordpress.org/support/topic/313946?replies=7
"This is a bug in the way we store rewrite_rules in "transients"
instead of options like we used to. I think our fix for WP 2.9 is
going to be to revert to the old method.

http://core.trac.wordpress.org/ticket/10981"

Correct usage of add_rewrite in plugin:
http://wordpress.org/support/topic/226529?replies=3
"Second, the problem is that add_rewrite_rule needs to come before
you flush the rules. I know it seems unintuitive, but what happens
when you flush the rules is that they're immediately regenerated,
at which point WordPress says, "hmm, what rewrite rules do I need
to include?"

I’m still scouring code and support forums looking for a solution. Between the two of us, we might just come up with something!

Success! So simple once you catch on…

The all important $wp_rewrite->flush_rules() can only be called from the Admin side. Makes sense, right? You wouldn’t want to be calling it every single page load.

This whole time, my code has been pretty much correct except for where I was calling the flush. Since it needs to be called from the Admin side, the hook is ‘admin_init‘:

add_action('admin_init', 'ftc_flush_rewrites');

Here is the complete functioning sample code:

function ftc_flush_rewrites() {
 global $wp_rewrite;
 $wp_rewrite->flush_rules();
}

function ftc_add_rewrites() {
 global $wp_rewrite;
 $ftc_new_non_wp_rules = array(
	'find/(this)' => '/addit.php?here=$1',
 );

 $wp_rewrite->non_wp_rules = $ftc_new_non_wp_rules + $wp_rewrite->non_wp_rules;
}

add_action('generate_rewrite_rules', 'ftc_add_rewrites');
add_action('admin_init', 'ftc_flush_rewrites');