I'm not even sure this is possible but before I start thinking up crazy solutions, I'll see if there is a WordPress way to do it.
Here's the deal.
I have a timeline jQuery plugin all set up on WordPress and I want it to be callable in a child theme through the add_theme_support method:
add_theme_support( 'timeline' );
Call it an obsession with modular design. I've probably read too much Tadlock for any one man's sanity but it's working for me.
So the first part works just fine.
I've got the stylesheet & js file all conditionally enqueued if theme support has been specified and the one nagging problem is that I can't conditionally include a new page template. Having a "Timeline" template show up when timeline support is disabled is just bad UX design.
So here's the question - is there a filter method for conditionally inserting a global page template from outside of the usual locations? For example, if I were to put my page template in /library/inc/conditionals/page-timeline.php (effectively hiding it from WordPress), how could I filter it back into the template list on a page? If I can figure that out, I can add the filter to my add_theme_support function, angels will fly, trumpets will sound, and I will be happy.
The problem is that I'm not familiar with that particular drop box or how to invoke it in an unusual way.
Thanks for your brains! (not-in-a-zombie-way)