Next.js 15：発見すべき新機能のすべて

1// ServerComponent.tsx
2import { useServerContext } from 'next/hooks';
3
4interface ServerData {
5  username: string;
6  role: string;
7}
8
9function ServerComponent() {
10  const serverData = useServerContext<ServerData>(); // サーバーデータの型付け
11  return <div>Server: {serverData.username} - {serverData.role}</div>;
12}
13export default ServerComponent;

1// ClientComponent.tsx
2import { useClientContext } from 'next/hooks';
3
4interface ClientData {
5  theme: string;
6  language: string;
7}
8
9function ClientComponent() {
10  const clientData = useClientContext<ClientData>(); // クライアントデータの型付け
11  return <div>Client: {clientData.theme} - {clientData.language}</div>;
12}
13export default ClientComponent;

1import { useLoadingState } from 'next/hooks';
2
3function LoadingComponent() {
4  const isLoading = useLoadingState();
5  return (
6    <div>
7      {isLoading ? <p>読み込み中...</p> : <p>読み込み完了！</p>}
8    </div>
9  );
10}
11export default LoadingComponent;