Next.js hydration — obrasci (Protos-Web, 2026-07-10)

Simptomi

• Stranica izgleda učitana ali klikovi ne rade (ULAZ, language switcher, animacije)
• React minified errors #418, #423, #425 u konzoli
• Korisnik: "jezici ne rade", "stranica ne radi" — curl vraća 200

Uzroci u Protos-Web

1. PageLoader + sessionStorage u useState initializeru

   • Server: uvijek loading=true
   • Client (returning visitor): loading=false odmah
   • → cijelo boot overlay tree mismatch

2. toLocaleDateString bez fiksne timezone

   • Server render (UTC) vs browser (lokalna TZ) → različit tekst datuma u blog karticama (#425)

3. Ručno element.remove() na React DOM node (#boot-ssr-veil)

   • → removeChild: The node to be removed is not a child of this node

Fix pattern

// PageLoader — deterministički initial state
const [loading, setLoading] = useState(true)

useLayoutEffect(() => {
  if (isBootComplete()) setLoading(false)
  else removeBootSsrVeil() // samo display:none, ne .remove()
}, [])

// Datumi — uvijek ista TZ na serveru i klijentu
toLocaleDateString(locale, { year: 'numeric', month: 'long', day: 'numeric', timeZone: 'UTC' })

Verifikacija

• Playwright s page.on('pageerror') — ne oslanjati se samo na curl
• Test: boot ULAZ → cookie accept → hero visible → language switch URL change

Ne miješati

• Boot gate (boot-pending / #boot-ssr-veil) s admin rutama — admin ide kroz AdminShell izvan boot flowa