Što su Route Handlers (API rute) u App Routeru?

Question

Accepted Answer

**Route Handlers** su način App Routera za izgradnju API krajnjih točaka — backend HTTP rukovaoca koji žive u vašem Next.js projektu. Kreirate ih s datotekom **`route.ts`**, izvozite funkcije nazvane prema HTTP metodama.

## Definiranje krajnje točke

```ts
// app/api/users/route.ts  →  serves /api/users
import { NextRequest, NextResponse } from "next/server";

export async function GET() {
  const users = await db.user.findMany();
  return NextResponse.json(users);             // GET /api/users
}

export async function POST(req: NextRequest) {
  const body = await req.json();               // read the request body
  const user = await db.user.create({ data: body });
  return NextResponse.json(user, { status: 201 }); // POST /api/users
}
```

Svaka izvezena metoda (`GET`, `POST`, `PUT`, `PATCH`, `DELETE`) obrađuje taj glagol. Koriste standardne Web `Request`/`Response` API-je (preko `NextRequest`/`NextResponse`).

## Čitanje parametara i upita

```ts
// app/api/users/[id]/route.ts → /api/users/123
export async function GET(req: NextRequest, { params }: { params: { id: string } }) {
  const url = new URL(req.url);
  const sort = url.searchParams.get("sort"); // ?sort=name
  const user = await db.user.findUnique({ where: { id: params.id } });
  return NextResponse.json(user);
}
```

## Kad koristiti Route Handlers vs Server Actions/Components

```text
Use Route Handlers for:
  ✓ Public APIs consumed by mobile apps / external clients
  ✓ Webhooks (Stripe, GitHub) — they need a URL endpoint
  ✓ Returning non-HTML (JSON, files, images, RSS)
  ✓ Client-side fetch() targets

Prefer Server Components for reading data into your own pages,
and Server Actions for form mutations — they avoid a manual API layer.
```

## Ostale mogućnosti

```ts
export const runtime = "edge";       // run on the Edge runtime
export const dynamic = "force-dynamic"; // opt out of caching
// Handlers can also stream responses, set cookies, and handle CORS.
```

## Zašto je to važno

Route Handlers čine Next.js full-stack: gradite REST/JSON API-je, webhooks i datotečne krajnje točke uz vašu frontend s web-standardnim `Request`/`Response`.

Znanje kada ih koristiti (vanjski klijenti, webhooks, ne-HTML odgovori) u odnosu na korištenje Server Components/Actions (čitanja internih podataka i mutacije) ključno je za čist strukturirani backend App Routera.