Custom Permalink

// alternativ mit 'save_post_{$post_type}'
add_action( 'save_post', 'set_custom_permalink', 10, 3 );

function set_custom_permalink($post_id, $post, $update ) {

        if ($post->post_name != '')
            return;

        // verify post is not a revision
        if ( wp_is_post_revision( $post_id ) )
            return;

        // unhook this function to prevent infinite looping
        remove_action( 'save_post', 'set_custom_permalink', 10, 3 );

        // update the post slug
        wp_update_post( array(
            'ID' => $post_id,
            'post_name' => 'my-custom-slug', // Replace with function to generate Slug
        ) );

        // re-hook this function
        add_action( 'save_post', 'set_custom_permalink', 10, 3 );

    }