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Untuk **ambil alamat dari longitudelatitude** itu namanya **reverse geocoding**.
Ada beberapa cara, tergantung mau **pakai API online** atau **offline**.
--- ---
## ✅ Contoh dasar (JavaScript) ## ✅ Cara PALING UMUM: Google Maps Reverse Geocoding
```js ### Contoh koordinat
async function getAlamat(lat, lng) {
const res = await fetch(
`https://nominatim.openstreetmap.org/reverse?lat=${lat}&lon=${lng}&format=json`
);
if (!res.ok) { ```
throw new Error(`HTTP error! status: ${res.status}`); lat = -6.200000
} lng = 106.816666
const data = await res.json();
return data.display_name;
}
// pakai
(async () => {
try {
const alamat = await getAlamat(-6.2, 106.816666);
console.log(alamat);
} catch (err) {
console.error(err);
}
})();
``` ```
--- ---
## ✅ Dengan **Google Maps API** ### 🔹 JavaScript (fetch)
```js ```js
async function getAlamatGoogle(lat, lng) { const lat = -6.2;
const apiKey = "API_KEY_KAMU"; const lng = 106.816666;
const url = `https://maps.googleapis.com/maps/api/geocode/json?latlng=${lat},${lng}&key=${apiKey}`; const apiKey = "API_KEY_KAMU";
const res = await fetch(url); fetch(`https://maps.googleapis.com/maps/api/geocode/json?latlng=${lat},${lng}&key=${apiKey}`)
const data = await res.json(); .then(res => res.json())
.then(data => {
console.log(data.results[0].formatted_address);
});
```
if (data.status !== "OK") { 📌 Output contoh:
throw new Error(data.status);
}
return data.results[0].formatted_address; ```
Jakarta, Daerah Khusus Ibukota Jakarta, Indonesia
```
---
### 🔹 Response penting dari Google
```json
{
"formatted_address": "Jl. MH Thamrin No.1, Jakarta Pusat, Indonesia",
"address_components": [
{ "long_name": "Jakarta Pusat", "types": ["administrative_area_level_2"] }
]
} }
``` ```
--- ---
## ✅ Ambil field detail (jalan, kota, dll) ## ✅ Alternatif GRATIS (tanpa API key): OpenStreetMap (Nominatim)
⚠️ Ada rate limit (jangan spam)
### JavaScript
```js ```js
async function getAlamatDetail(lat, lng) { fetch(`https://nominatim.openstreetmap.org/reverse?lat=-6.2&lon=106.816666&format=json`)
const res = await fetch( .then(res => res.json())
`https://nominatim.openstreetmap.org/reverse?lat=${lat}&lon=${lng}&format=json` .then(data => {
); console.log(data.display_name);
const data = await res.json(); });
```
const a = data.address; 📌 Output:
return {
jalan: a.road, ```
kecamatan: a.suburb, Jakarta Pusat, DKI Jakarta, Indonesia
kota: a.city || a.town,
provinsi: a.state,
negara: a.country,
kodepos: a.postcode,
};
}
``` ```
--- ---
## ⚠️ Best practice (penting) ## ✅ Flutter (sering dipakai di mobile)
### 🔹 Tambahkan User-Agent (wajib untuk OSM) ### Pakai `geocoding` package
```js ```dart
fetch(url, { import 'package:geocoding/geocoding.dart';
headers: {
"User-Agent": "MyApp/1.0 (email@example.com)" List<Placemark> placemarks =
} await placemarkFromCoordinates(-6.2, 106.816666);
});
Placemark place = placemarks.first;
print(place.street);
print(place.locality);
print(place.country);
``` ```
### 🔹 Hindari spam request
* Cache hasil
* Delay antar request
--- ---
## 🔥 Versi super ringkas ## ✅ Golang (pakai OpenStreetMap)
```js ```go
const alamat = await ( resp, _ := http.Get(
await fetch(`https://nominatim.openstreetmap.org/reverse?lat=-6.2&lon=106.816666&format=json`) "https://nominatim.openstreetmap.org/reverse?lat=-6.2&lon=106.816666&format=json",
).json(); )
defer resp.Body.Close()
console.log(alamat.display_name); var result map[string]interface{}
json.NewDecoder(resp.Body).Decode(&result)
fmt.Println(result["display_name"])
``` ```
---
## ⚠️ Penting diketahui
* Reverse geocoding **tidak 100% presisi**
* Bisa beda hasil antar provider
* Google = paling akurat, tapi **berbayar**
* OSM = gratis, tapi **lebih lambat**
---
## 🔥 Mau hasil lebih detail?
Kamu bisa ambil:
* Jalan
* Kecamatan
* Kota
* Provinsi
* Kode pos
Tinggal bilang:
* **pakai bahasa apa** (JS / Flutter / Go)
* **provider** (Google / OSM / Mapbox)
* mau **online atau offline**
Nanti aku bikinin contoh **siap copypaste** 👍