Customizing Category Pages

[gjh42]

Actually, considering this

$tpl_page_body = 'tpl_index_product_list.php';

you could probably put the conditional handling in a custom template copy of tpl_index_product_list.php, which would be better.
/includes/templates/your_template/templates/tpl_index_product_list.php

Sometimes the module file calls the tpl file, and sometimes it works the other way - I'm not sure why except that that is the way they were set up originally...

[gjh42]

Right, it's been a while since I've worked with the product listing page... the file that calls product_listing.php is /includes/templates/your_template/templates/tpl_modules_product_listing.php, which is called by tpl_index_product_listing.php.

Each layer of these files does some layout work, so where you need to intervene depends on what kinds of modifications you want to make.