// Arthur - custom template selon custom category
add_filter('single_template','check_for_category_single_template');
function check_for_category_single_template($t) {
	$cats = get_the_terms(get_the_ID(),'project-type');
	foreach((array)$cats as $cat) {
		if (file_exists(get_stylesheet_directory().'/single-'.$cat->slug.'.php'))
			return get_stylesheet_directory().'/single-'.$cat->slug.'.php'; 
		if ($cat->parent) {
			$cat = get_the_category_by_ID($cat->parent);
			if (file_exists(get_stylesheet_directory().'/single-'.$cat->slug.'.php'))
				return get_stylesheet_directory().'/single-'.$cat->slug.'.php';
		}
	}
	return $t;
}