checks if header and/or footer is disabled on page and adds a body class

add-blocksy-bodyclasses.php

<?php
function add_blocksy_bodyclasses($classes){
    if($blocksy = get_post_meta(get_the_ID(),"blocksy_post_meta_options",true)){
        if(isset($blocksy["disable_header"]) && $blocksy["disable_header"] == "yes")
            $classes[] = "blocksy-header-disabled";
        if(isset($blocksy["disable_footer"]) && $blocksy["disable_footer"] == "yes")
            $classes[] = "blocksy-footer-disabled";
    }
    return $classes;
    
}
add_filter('body_class','add_blocksy_bodyclasses');