Никита Токарев

const focusedCallbacks = new WeakMap();
document.addEventListener('click', (e) => {
    let target = e.target,
        open = target.dataset.open ? target.dataset.open : 0,
        close = target.dataset.close ? target.dataset.close : 0,
        element = open || close ? document.querySelector(`[data-window=${open || close}]`) : 0,
        

    if (open) {
        element.classList.add(`${element.dataset.window}-open`);
        focusedCallback.set(element,trapFocus.bind(null, element));
        element.addEventListener('keydown', focusedCallback.get(element));
    }
    
    if (close) {
        element.classList.remove(`${element.dataset.window}-open`);
        element.removeEventListener('keydown', focusedCallback.get(element));
        focusedCallback.delete(element);
    }
});