use CKEDITOR popup in Bootstrap modal


$(function() {
    $.fn.modal.Constructor.prototype.enforceFocus = function () {
        var $modalElement = this.$element;
        $(document).on('focusin.modal', function (e) {
            var $parent = $(e.target.parentNode);
            if ($modalElement[0] !== e.target && !$modalElement.has(e.target).length
                // add whatever conditions you need here:
                &&
                !$parent.hasClass('cke_dialog_ui_input_select') && !$parent.hasClass('cke_dialog_ui_input_text')) {
                $modalElement.focus()
            }
        })
    };
});