Kif jaħdmu l-varjabbli tal-ambent f'Next.js?

Question

Accepted Answer

Next.js ilaqqq il-varjabbli tal-ambent minn fajlijiet `.env`, b'regola sigurtà importanti: il-varjabbli huma **server-only l-imissier**, u biss dawk li jibdew b'prefiss `NEXT_PUBLIC_` jiddisklinaw lill-browser.

## Il-fajlijiet

```text
.env                # loaded in all environments
.env.local          # local overrides — GITIGNORED (put secrets here)
.env.development    # only in `next dev`
.env.production     # only in production builds
```

## Ir-regola tal-prefiss kritika

```bash
# .env.local
DATABASE_URL=postgres://...secret...   # server-only — NEVER sent to the browser
NEXT_PUBLIC_API_URL=https://api.example.com  # exposed to the browser
```

```tsx
// Server Component / Route Handler / Server Action — can read anything
const db = process.env.DATABASE_URL;          // ✅ works on the server

// Client Component — only NEXT_PUBLIC_* are available
"use client";
const api = process.env.NEXT_PUBLIC_API_URL;  // ✅ works
const secret = process.env.DATABASE_URL;      // ❌ undefined in the browser
```

Ir-regola tal-prefiss din hija **karatteristika tas-sigurtà**: tipprévjeni inti milli tissiġihx bi \ "l-alḳ passwords tad-database jew sigriet tal-API lill-client. Varjabbli mingħajr prefiss sempliċement ma jeszistix fil-bundels tal-browser.

## Kif il-valuri NEXT_PUBLIC_ huma integrati

```text
NEXT_PUBLIC_* are INLINED at BUILD time (baked into the JS bundle).
```

Oħra huma integrati fil-ħin tal-binja, it-tibdil ta 'valur `NEXT_PUBLIC_` jeħtieġ **rebuild** — u m'għandekx qatt tiddoq sigriet veri wara l-prefiss (ikunu viżibbli fil-bundel lil ħadd).

## L-aħjar prattiki

```text
✓ Secrets (DB URLs, API keys) → no prefix, kept server-side, in .env.local (gitignored)
✓ Public config (public API base, analytics id) → NEXT_PUBLIC_
✓ Commit a .env.example documenting required vars (no real values)
```

## Għaliex huwa importanti

Il-mudell server-only l-imissier b'scelta opt-in `NEXT_PUBLIC_` huwa l-obstakolu ta 'Next.js kontra ħ-tnixxija ta' sigriet lill-client — żalata komuni u serja.

L-għarfien tal-varjabbli li jilħqu l-browser, li l-valuri pubbliċi huma integrati fil-ħin tal-binja, u fejn li tittieħed sigriet (`.env.local` negligjat git) huwa essenzjali għal kemm il-funzjonalità kif ukoll is-sigurtà.