flutter_i18n 0.8.3

flutter_i18n #

I18n made easy, for Flutter!

Why you should use flutter_i18n? #

The main goal of flutter_i18n is to simplify the i18n process in Flutter. I would like to recreate the same experience that you have with the Angular i18n: simple json files, one for each language that you want to support.

Configuration #

To use this library, you must create a folder in your project's root: the basePath. Some examples:

/assets/flutter_i18n (the default one)



Inside this folder, you'll put the json or yaml files containing the translated keys. You have two options:

  • If you want to specify the country code


  • otherwise


If the json file is not available, we will look for a yaml file with the same name. In case both exist, the json file will be used.

Of course, you must declare the subtree in your pubspec.yaml as assets:

    - {basePath}

The next step consist in the configuration of the localizationsDelegates; to use flutter_i18n, you should configure as follows:

localizationsDelegates: [

Below you can find the name and description of the accepted parameters.

The useCountryCode parameter depends on the json configuration:

  • if you used the pattern {languageCode}_{countryCode}, useCountryCode must be true
  • if you used the pattern {languageCode}, useCountryCode must be false

The fallbackFile parameter was entroduces with the version 0.1.0 and provide a default language, used when the translation for the current running system is not provided. This should contain the name of a valid json file in assets folder.

The path parameter is optionally used to set the base path for translations. If this option is not set, the default path will be assets/flutter_i18n. This path must be the same path as the one defined in your pubspec.yaml.

The forcedLocale parameter is optionally used to force a locale instead finding the system one.

If there isn't any translation available for the required key, the same key is returned.

flutter_i18n in action #

After the configuration steps, the only thing to do is invoke the following method:

FlutterI18n.translate(buildContext, "your.key")


  • buildContext is the BuildContext instance of the widget
  • your.key is the key to translate

Other examples of use:

Force a language to be loaded at run-time:

await FlutterI18n.refresh(buildContext, languageCode, {countryCode});

Plural translations:

FlutterI18n.plural(buildContext, "your.key", pluralValue);

For more informations and details, read the CHANGELOG.md.

Known problems:

  • In iOS simulator, is always used the en_US locale: see here.


flutter_i18n now manage strings that contain parameters; an example can be: "Hello, {user}!" For a correct translation, you must use the third parameter of the translate method, a Map<String, String> where:

  • the keys are the placeholders used in the .json file (i.e. user)
  • the values are what you want to display


flutter_i18n now supports language change at runtime. To use it, you must invoke the method

await FlutterI18n.refresh(buildContext, languageCode, {countryCode});

NOTE: countryCode is optional.


flutter_i18n now supports plurals. To use it, invoke the method:

FlutterI18n.plural(buildContext, "your.key", pluralValue);

Where pluralValue is the integer value that will be used to determinate the plural form of the translation.

Here is an example of configuration of the .json file:

"clicked": {
    "times-0": "You clicked {times} times!",
    "times-1": "You clicked {time} time!",
    "times-2": "You clicked {times} times!"

With this configuration, you must invoke the plural method as follow:

FlutterI18n.plural(buildContext, "clicked.times", pluralValue);

FlutterI18n will choose the right key using the value of pluralValue: it will match the last key with a value <= of pluralValue.


flutter_i18n now supports the basePath configuration. The default one is: assets/flutter_i18n. To configure it, use the third optional parameter of FlutterI18nDelegate.


Print in log when a key is not found.


Fix for bug #10.


Exposed new method that return the locale used by the library, as requested in #16:


NOTE: the refresh method now accept a Locale as second parameter, instead of two strings. NOTE: the constructor of FlutterI18nDelegate now accept only named parameter.


Fix for bug #22


Fix for the delegate


Fix for #17


Fix for #41


Fix for #48 and implemented feature for #49. From this version of FlutterI18n, you can use as 4th parameter the forcedLanguage parameter, in order to avoid to call the refresh method on application startup.


Support for yml language files


Improved json and yml loading


Bugfix and code improvement


Library will print debug messages only in development mode


example #

A new Flutter project.

Getting Started #

For help getting started with Flutter, view our online documentation.

Use this package as a library

1. Depend on it

Add this to your package's pubspec.yaml file:

  flutter_i18n: ^0.8.3

2. Install it

You can install packages from the command line:

with Flutter:

$ flutter pub get

Alternatively, your editor might support flutter pub get. Check the docs for your editor to learn more.

3. Import it

Now in your Dart code, you can use:

import 'package:flutter_i18n/flutter_i18n.dart';
Describes how popular the package is relative to other packages. [more]
Code health derived from static analysis. [more]
Reflects how tidy and up-to-date the package is. [more]
Weighted score of the above. [more]
Learn more about scoring.

We analyzed this package on Feb 18, 2020, and provided a score, details, and suggestions below. Analysis was completed with status completed using:

  • Dart: 2.7.1
  • pana: 0.13.5
  • Flutter: 1.12.13+hotfix.7

Health suggestions

Format lib/flutter_i18n.dart.

Run flutter format to format lib/flutter_i18n.dart.


Package Constraint Resolved Available
Direct dependencies
Dart SDK >=1.19.0 <3.0.0
flutter 0.0.0
flutter_localizations 0.0.0
yaml ^2.2.0 2.2.0
Transitive dependencies
charcode 1.1.3
collection 1.14.11 1.14.12
intl 0.16.0 0.16.1
meta 1.1.8
path 1.6.4
sky_engine 0.0.99
source_span 1.6.0
string_scanner 1.0.5
term_glyph 1.1.0
typed_data 1.1.6
vector_math 2.0.8
Dev dependencies