simple-jquery-bootstrap-validation.js

    $.each($("#orders_modal input, #orders_modal textarea, #orders_modal select"), function (index, value) {
        if($(value).attr("required") === undefined){
            return;            
        }else{
            if(!$(value).val()){
                $(value).addClass("is-invalid")
            }else{
                $(value).removeClass("is-invalid")
            }
        }

    });