Alphabetizing Posts

Hi there,

I created a page with a menu in the left side bar where you can choose post by catogory (Selecteer op soort:), by tag (Selecteer op doelgroep:), or you can look up all the post in alphabetical order (Van A tot en met Z:). This last one is the actual post page on the website.

I used some custum code from the WordPress Codex in my childtheme functions.php to alphabetize the post:

function foo_modify_query_order( $query ) {
    if ( $query->is_home() && $query->is_main_query() ) {
        $query->set( 'orderby', 'title' );
        $query->set( 'order', 'ASC' );
    }
}
add_action( 'pre_get_posts', 'foo_modify_query_order' );

This works great for the actual post page (Van A tot en met Z:). But when you look at the post by catagory or tag they appear in random order. What i want is that all my post always appear in alphabetical order. How can i manage this?

I am pretty new with WordPress and custom coding. So maby there is a simple solution, but i don’t see it. Hope you can help.

Thanks