bangladesh_geo_postcode 0.0.2

Offline Bangladesh geographic postcode lookup with Division, District, Thana and Postcode search. Supports Bangla and English. Uses Protocol Buffers for fast loading.

bangladesh_geo_postcode

Offline Bangladesh geographic postcode lookup for Flutter. Supports Division > District > Thana > Postcode navigation in both Bangla and English.

Uses Protocol Buffers for fast binary loading — no database, no API, fully offline.

Features

• Division / District / Thana / Postcode hierarchy
• Bangla & English language support
• O(1) postcode search (supports both 1206 and ১২০৬)
• One-time protobuf load, in-memory cache
• No network, no SQLite, no external dependency

Getting Started

1. Add dependency

dependencies:
  bangladesh_geo_postcode: ^0.0.1

2. Initialise at app startup

import 'package:bangladesh_geo_postcode/bangladesh_geo_postcode.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await LocationCache.instance.load();
  runApp(MyApp());
}

Usage

const service = LocationService();

// Get all divisions
final divisions = service.getDivisions(Language.en);
final divisionsBn = service.getDivisions(Language.bn);

// Get districts in a division
final districts = service.getDistricts('Dhaka', Language.en);

// Get thanas in a district
final thanas = service.getThanas('Dhaka', 'Dhaka', Language.en);

// Search by postcode (English or Bangla)
final result = service.searchByPostcode('1206');
final resultBn = service.searchByPostcode('১২০৬');

// Access location fields
if (result != null) {
  print(result.divisionEn);   // Dhaka
  print(result.districtBn);   // ঢাকা
  print(result.thanaEn);      // Dhaka
  print(result.postcodeEn);   // 1206
  print(result.postcodeBn);   // ১২০৬
  print(result.subofficeEn);  // Dhaka Cantonment--TSO
}

// Get all postcodes in a division
final divCodes = service.getPostcodesByDivision('Dhaka');

// Get all postcodes in a district
final distCodes = service.getPostcodesByDistrict('Dhaka', 'Dhaka');

// Get all postcodes in a thana
final thanaCodes = service.getPostcodesByThana('Dhaka', 'Dhaka', 'Dhamrai');

Bangla Postcode Search

The postcode normalizer automatically converts Bangla digits to English for matching:

// Both return the same result
service.searchByPostcode('1206');
service.searchByPostcode('১২০৬');

You can also use the normalizer directly:

final normalized = normalizePostcode('১২০৬'); // "1206"

API Reference

LocationCache

Method	Description
LocationCache.instance.load()	Load data into memory (call once at startup)
LocationCache.instance.isLoaded	Whether data has been loaded

LocationService

Method	Returns	Description
getDivisions(Language)	List<String>	All unique division names
getDistricts(division, Language)	List<String>	Districts within a division
getThanas(division, district, Language)	List<String>	Thanas within a district
searchByPostcode(postcode)	Location?	First match for a postcode
searchAllByPostcode(postcode)	List<Location>	All matches for a postcode
getPostcodesByDivision(division)	List<Location>	All locations in a division
getPostcodesByDistrict(division, district)	List<Location>	All locations in a district
getPostcodesByThana(division, district, thana)	List<Location>	All locations in a thana
getAll()	List<Location>	Every loaded location

Location Fields

Field	Type	Description
divisionEn / divisionBn	String	Division name
districtEn / districtBn	String	District name
thanaEn / thanaBn	String	Thana name
subofficeEn / subofficeBn	String	Sub-office name
postcodeEn / postcodeBn	String	Postcode

Language

enum Language { en, bn }

License

MIT