Shortcodes in WordPress are extreamly usefull for applying formatting or embeding external content in your pages or posts.
The only problem with them is the parser only does a single pass on the content, so if your shortcodes outputs a shortcode, or you have a shortcode nested within shortcodes, they wont render.
I found on the WordPress Codex that, to enable nesting shortcodes, or shortcodes within shortcodes, I would have to add
return do_shortcode($content); This way it will push the result back into the parser.
That’s all very well, but what of shortcodes I didn’t make, or don’t have this added to them? So I made a little plugin that would override the default do_shortcode filter with an evaluator that would check for shortcodes and keep pushing it to do_shortcode until they are all done.
Plugin Name: Shortcode Recursion
Description: Adds shortcode recursion for shortcodes that have shortcodes in shortcodes that has a shortcode in a shortcode in a shortcode with a shortcode in it, all wrapped in a shortcode within a shortcode... and so on.
Author: David Cramer
Author URI: http://digilab.co.za/
/* evaluates content for shortcodes and sends it to do_shortcode() if needed and revaluates the result */
// evaluate content for shortcodes.
preg_match_all("/".get_shortcode_regex()."/s", $content, $matches);
// if has shortcode, return revaluated content from native do_shortcode
// return if nothing is found
// remove the native do_shortcode filter
remove_filter('the_content', 'do_shortcode', 11);
// replace the filter with the evaluator function
add_filter('the_content', 'shortcode_inception', 11);