ISR & Revalidation — Series 2

Preview — 3 of 10 questions

A page has three sibling <Suspense> boundaries whose components resolve after 100ms, 500ms, and 200ms. In what order does the content appear?

javascript

<Suspense fallback={<Skeleton />}><SlowPanel /></Suspense>   {/* 500ms */}
<Suspense fallback={<Skeleton />}><FastPanel /></Suspense>   {/* 100ms */}
<Suspense fallback={<Skeleton />}><MediumPanel /></Suspense> {/* 200ms */}

AAll three appear at once when the slowest resolves

BIn reverse order of resolve time

CStrictly in JSX source order, each waiting for the previous

DIn the order they resolve — the 100ms panel first, then 200ms, then 500ms — each streaming in independently as soon as its own data is ready, regardless of JSX position

How do you show a Submitting… state on a submit button without lifting useState into the form component?

ACall useFormStatus() (from react-dom) inside a Client Component nested within the <form> — it reads the enclosing form's { pending, data, method, action }

BCheck document.activeElement in a useEffect

CRead formData.get('pending') in the Server Action

DSet disabled permanently and clear it on a timeout

How do you display a validation error returned by a Server Action, tied to the failed submission?

AWrite the error into a global Zustand store from the Server Action

BWrap the form's onSubmit in a client try/catch

CWrap the action with useActionState(action, initialState) — the action returns { error }, that value becomes the hook's state, and the component renders the message from it, no manual client wiring

DRead window.lastFormError set by the Server Action

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