sealed_countries 2.6.0⧉

This ISO-driven, fully tested and pure Dart package provides information about world countries in the form of compile-time, tree-shakable constant classes with a sealed origin. Contains all 249+1 countries with ISO 3166 codes, their English, native names, emoji flags, capitals, population, postal codes, phone codes, languages (and scripts), currencies, country/currency/language name translations, etc. For Flutter ready widgets, please use world_countries package.

Features

WorldCountry class provides the following information about countries:

Provides a compile-time constant of all countries accessible via WorldCountry.list moreover, the WorldCountry class provides the following methods/constructors:

• maybeFromAnyCode - returns a country instance if the value matches any ISO 3166 code, otherwise returns null.
• fromAnyCode - returns a country instance if the value matches any ISO 3166 code.
• maybeFromValue - returns a country instance if the value matches the provided value, otherwise returns null.
• fromCode - returns a country instance if the value matches the provided ISO 3166-1 Alpha-3 code.
• fromCodeShort - returns a country instance if the value matches the provided ISO 3166-1 Alpha-2 code.
• fromCodeNumeric - returns a country instance if the value matches the provided ISO 3166-1 numeric code.
• maybeFromCode - returns a country instance if the value matches the provided ISO 3166-1 Alpha-3 code, otherwise returns null.
• maybeFromCodeShort - returns a country instance if the value matches the provided ISO 3166-1 Alpha-2 code, otherwise returns null.
• maybeFromCodeNumeric - returns a country instance if the value matches the provided ISO 3166-1 numeric code, otherwise returns null.
• permissive - allows the creation of custom class instances that are not fully compatible with the ISO standard.

You can also find many common methods you may know from Dart ecosystem - toString overrides, copyWith, toJson, compareTo, etc. Also, a compile-time const, tree-shakable, case-insensitive code maps (for O(1)-time code look-ups), list, and much more.

[!TIP] Translations: Use maybeCommonNameFor() or commonNameFor() methods to get translations for specific locale.

Getting started

To use this package, add sealed_countries as a dependency in your pubspec.yaml file.

dependencies:
  sealed_countries: any

Then import the package in your Dart code:

import 'package:sealed_countries/sealed_countries.dart';

Usage

To get information about countries, use the WorldCountry class. You can construct instances directly (using const), use the class's factory constructors or static methods, or select a country from the WorldCountry.list constant.

  print(WorldCountry.list.length); // Prints: "250".

  final country = WorldCountry.fromCode("MEX");
  print(country.name.common); // Prints: "Mexico".

  final europeanCountries = WorldCountry.list.where(
    (cnt) => cnt.continent is Europe,
  );
  print(europeanCountries); // Prints a list of European countries.

  // Prints German translations of all available regular countries.
  final germanNames = WorldCountry.list.commonNamesMap(
    options: const LocaleMappingOptions(
      mainLocale: BasicTypedLocale(LangDeu()),
    ),
  );

  print(
    """Fully translated to German: ${germanNames.length == WorldCountry.list.length}""",
  ); // Prints: "Fully translated to German: true".
  for (final deuTranslation in germanNames.entries) {
    print("German name of ${deuTranslation.key.name}: ${deuTranslation.value}");
  }

[!IMPORTANT] For specific ISO instances and their collections, e.g., const value = CountryChn(), const items = [CountryChn()] — prioritize compile-time constant references over var/final to ensure canonicalization and benefit from compiler optimizations.

For more usage examples, please see the /example folder.

FAQ

How do I get all countries using a specific currency?

• Quick/simple way (more suitable for a single currency): .where

  final usdCountries = WorldCountry.list.where( // All countries using USD.
    (country) => country.currencies?.contains(const FiatUsd()) ?? false,
  );
  

• Advanced (more suitable for multiple currencies, sorted by population): .byCountryMap()

  final map = const [FiatUsd(), FiatEur()].byCountryMap(); // All countries using USD or EUR.
  final allCountries = {for (final list in map.values) ...list};
  

Why should I use this package over any other country-related package?

• Classes with a sealed origin: This package provides data via classes with a sealed origin, defining specific permitted direct subclasses. This lets you use instances of these subclasses and customize their data or behavior (e.g., overriding methods), offering more structured flexibility than enums or standard open classes.
• No 3rd-party dependencies: This package has no third-party dependencies, ensuring that you won't have any issues or conflicts with other dependencies (no even meta here, because of that).
• Rich data: This package offers far more data than any other package + tons of translations (all GlobalMaterialLocalizations and GlobalCupertinoLocalizations locales and more).
• Type-safe: The contracts and types in this package are exceptionally strong, ensuring that your code is strongly typed and well-defined.
• High code coverage: The code in this package has 100% code coverage, with more than 1K (+2K in underlying packages) tests, providing confidence in its reliability and stability.
• Comprehensive documentation: This package provides full documentation for every non-code generated public member, usually with examples, ensuring clarity and ease of use.
• Mirrored Repository: The GitHub repository, including all package tags, is mirrored on GitLab, providing an alternative access point should GitHub become unavailable.
• Industry adopted: This package is actively used in production by numerous European companies, ensuring its efficacy and robustness in real-world scenarios.
• MIT license: This package and sources are released under the MIT license, which is a permissive license that allows users to use, modify, and distribute the code with minimal restrictions. The MIT license is considered better than most other open-source licenses because it provides flexibility and allows users to incorporate the code into their projects without worrying about legal implications.

Additional information

If you like this package, please give it a star or like. For more information on using this package, check out the API documentation. PRs or ideas are always welcome. If you have any issues or suggestions for the package, please file them in the GitHub repository.

References, credits and sources

• ISO
• Wikipedia
• Data Source²
• Project Roadmap

¹ For the standard ISO classes specified in the relevant ISO standard.

² Translated JSON data to Dart language (following Effective Dart: Style guidelines), added additional data and functionality in Dart classes.