Remove unnecessary classes

[billerickson]

Specifically on body_class, post_class, and nav_menu_css_class

Right now with Leites on Pagely we keep going over bandwidth limits, so I’ve been analyzing stuff. They have a fairly moderate to large primary navigation (lots of dropdowns etc). So, I filtered to remove all the BS classes on the nav items except "current-menu" type classes. Since nav is on every page of the site, doing that made the HTML page size go down 5+ kb globally. 5kb over an average of 8 million page views a month translates to ​_40 gigs_​ saved in bandwidth per month…. 😮 which is 20% of the monthly bandwidth allotment

[jaredatch]

This needs to be tweaked more, since this is more or less a straight adaption from StackOverflow, but you get the gist.

function lc_clean_wp_nav_menu($var) {

    return is_array( $var ) ? array_intersect( $var, array(
        //  'menu-item',
            'current_page_item',
            'current_page_parent',
            'current_page_ancestor',
            )
    ) : '';
}
add_filter('nav_menu_css_class', 'lc_clean_wp_nav_menu');
add_filter('nav_menu_item_id', 'lc_clean_wp_nav_menu');
add_filter('page_css_class', 'lc_clean_wp_nav_menu');