How can I increase the post count for custom post types only?

Question

I have the page count set to the default 10 in my reading settings menu.

However, I use my template archive.php file for all post types, including posts and books

How can I change the loop so that when searching books it will show 30 books in the archive page instead of showing the default 10?

Answer 1

I think something like this should work:

add_action('parse_query', 'wpse32932_parse_query'); 
function wpse32932_parse_query( $wp ){
    if( $wp->is_post_type_archive ):
        $wp->query_vars['posts_per_page'] = 30;
    endif;
    return $wp;
}