React Pro - Real World App - Ch7. 12. 12. Componente -IfLogged-- protezione DOM, Fragment and PropsW

// NavBar.tsx
import { selectAuthIsLogged, useAuth } from '@/services/auth';
import { NavLink, useNavigate } from 'react-router-dom';
import logo from '../../../assets/laptop.png';
import { selectCartIsEmpty, selectTotalCartItems, useCart, useCartPanel } from '@/services/cart';
import { IfLogged } from '../auth/IfLogged';
import { CartPanel } from './CartPanel';

const isActive = (obj: { isActive: boolean }) => {
  return obj.isActive ? 'text-xl text-sky-400 font-bold' : 'text-xl text-white'
}

export function NavBar() {
  const navigate = useNavigate();
  const logout = useAuth(state => state.logout);

  const isCartPanelOpened = useCartPanel(state => state.open);
  const toggleCartPanel = useCartPanel(state => state.toggle);
  const totalCartItems = useCart(selectTotalCartItems);
  const isEmpty = useCart(selectCartIsEmpty);

  function logoutHandler() {
    logout();
    navigate('/login')
  }

  return (
    <div className="fixed top-0 left-0 right-0 shadow-2xl z-10">
      <div className="bg-slate-900 flex justify-between items-center h-20 text-white p-3">

        {/*Logo*/}
        <div className="flex items-center gap-3">
          <img src={logo} alt="my logo" className="w-16"/>
          <NavLink to="shop" className={isActive}>SHOP</NavLink>
        </div>

        {/*Cart button badge*/}
        <div>
          <button disabled={isEmpty} className="btn accent lg" onClick={toggleCartPanel}>
            Cart: {totalCartItems}
          </button>
        </div>

        {/*Cart Panel*/}
        { isCartPanelOpened && <CartPanel/>}


        {/*actions button*/}
        <div className="fixed bottom-2 right-2 p-5">
          <NavLink to="login" className="btn accent lg">login</NavLink>
          <NavLink to="cms" className="btn accent lg">cms</NavLink>
          <IfLogged>
            <button onClick={logoutHandler} className="btn primary lg">logout</button>
          </IfLogged>
        </div>

      </div>
    </div>
  )
}