tradutor 0.5.1

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A Flutter package that simplify the internationalizing process using JSON and YAML files. Extracts messages to generate Dart files with friendly way to access messages you need.

String get translator => "tradutor";


Features #

  • Simple messages;
  • Messages with multiple parameters;
  • List of simple messages;
  • List of messages with multiple parameters;
  • Plural messages;
  • Allow a language extends another language;
  • JSON and YAML files;
  • Supports Flutter Web;
  • Supports hot reload.

Installation #

In pubspec.yaml add the following dependencies:

        sdk: flutter 

    tradutor: ^0.5.1

Usage #

Open a terminal inside your project directory and run the following command:

flutter packages pub run tradutor:build

All supported arguments:

  • --source "DIRECTORY PATH" or -s "DIRECTORY PATH": A source folder contains all JSON/YAML files (defaults to "./i18n");
  • --output "FILE PATH" or -o "FILE PATH": An output file contains all strings (defaults to "./lib/i18n.dart");
  • --fallback "LANGUAGE" or -f "LANGUAGE": Provides a default language, used when the translation for the current running system is not provided (defaults to "en_US");
  • --watch: Watches the JSON/YAML files for edits and does rebuilds as necessary.
  • --class-name "NAME" or -c "NAME": Allows change the generated Dart class name (defaults to "I18n").
  • --web: Use this for generate Dart file prepared for Flutter Web.

Full example: flutter packages pub run tradutor:build -s "/i18n" -o "/lib/i18n.dart" -f "en_US" -c "I18n" --watch

JSON Files #

Crete JSON files naming them with language code (lowercase) and country code (uppercase). Ex.: pt_BR.json, en_US.json, etc.


    "simpleMessage": "This is a simple Message",
    "messageWithParameters": "Hi {name}, Welcome you!",
    "brazilFlagColors": ["Green", "Yellow", "Blue", "White"],
    "simpleWhiteCakeIngredients": [
        "{whiteSugar} cup white sugar",
        "{butter} cup butter",
        "{eggs} eggs",
        "{vanilla} teaspoons vanilla extract",
        "{flour} cups all-purpose flour",
        "{bakingPowder} teaspoons baking powder",
        "{milk} cup milk"
    "homePage": {
        "title": "Home Page"
    "": "Button clicked 1 time",
    "counter.other": "Button cliked {quantity} times"

YAML Files #

Crete YAML files naming them with language code (lowercase) and country code (uppercase). Ex.: pt_BR.yaml, en_US.yaml, etc.

simpleMessage: これは簡単なメッセージです
messageWithParameters: "{name}様、ようこそ!"
- 緑
- 黄色
- 青い
- 白い
- "白砂糖{whiteSugar}カップ"
- "バター{butter}カップ"
- "卵{eggs}個"
- "バニラエッセンス小さじ{vanilla}"
- "薄力粉{flour}カップ"
- "小さじ{bakingPowder}杯のベーキングパウダー"
- "牛乳{milk}カップ"
  title: ホームページ
counter.other: ボタンが{quantity}回クリックされた

Supported Message Type #

Simple message #

    "simpleMessage": "This is a simple Message"

Generated Dart getter:

String get simpleMessage => "This is a simple Message";

Message with parameters #

Use {parameterName} in a message.

    "messageWithParameters": "Hi {name}, Welcome you!"

Generated Dart method:

String messageWithParameters(name) => "Hi $name, Welcome you!";

List of simple messages #

Define an array of strings.

    "brazilFlagColors": ["Green", "Yellow", "Blue", "White"]

Generated Dart getter:

List<String> get brazilFlagColors => ["Green", "Yellow", "Blue", "White"];

List of messages with multiple parameters #

    "simpleWhiteCakeIngredients": [
        "{whiteSugar} cup white sugar",
        "{butter} cup butter",
        "{eggs} eggs",
        "{vanilla} teaspoons vanilla extract",
        "{flour} cups all-purpose flour",
        "{bakingPowder} teaspoons baking powder",
        "{milk} cup milk"

Generated Dart getter:

List<String> simpleWhiteCakeIngredients(
          bakingPowder, butter, eggs, flour, milk, vanilla, whiteSugar) =>
        "${whiteSugar} cup white sugar",
        "${butter} cup butter",
        "${eggs} eggs",
        "${vanilla} teaspoons vanilla extract",
        "${flour} cups all-purpose flour",
        "${bakingPowder} teaspoons baking powder",
        "${milk} cup milk"

Plural messages #

    "": "Button clicked 1 time",
    "counter.other": "Button cliked {quantity} times"

The 'other' plural form must be provided.

quantity is the parameter used to format a message depending on its value.

Generated Dart method:

String counter(quantity) => Intl.plural(
        locale: language,
        one: "Button clicked 1 time",
        other: "Button cliked ${quantity} times",

Usage of Generated Dart file (i18n.dart) #

import 'package:flutter/material.dart';
import 'package:flutter_localizations/flutter_localizations.dart';

import 'i18n.dart';

void main() => runApp(App());

class App extends StatelessWidget {
  Widget build(BuildContext context) {
    final i18n = I18n.delegate;

    return MaterialApp(
        title: 'Tradutor',
        theme: ThemeData(
        home: HomePage(),
        localizationsDelegates: [
        supportedLocales: i18n.supportedLocales,
            i18n.resolution(fallback: Locale("en", "US")));
class _HomePageState extends State<HomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {

  Widget build(BuildContext context) {
    final i18n = I18n.of(context);
    return Scaffold(
      appBar: AppBar(
        title: Text(i18n.homePageTitle),
      body: Center(
        child: Column(
          children: <Widget>[
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        child: Icon(Icons.add),

Extending from another language #

Use property @extends and a valid locale.


    "@extends": "pt_PT",
    "": "Botão foi pressionado {quantity} vez",
    "counter.other": "Botão foi pressionado {quantity} vezes"

You must override all plural forms for a specified message.

Other language properties #

  • @textDirection: valid values are ltr (default) and rtl;

[0.5.1] - 2019-08-25

  • Bug fixed.

[0.5.0] - 2019-08-25

  • Added support to Flutter Web;
  • Added widget tests.

[0.4.0] - 2019-08-11

  • Added support to YAML files.

[0.3.0] - 2019-08-09

  • Added support to change the generated Dart class name.

[0.2.0] - 2019-08-09

  • Added support to nested messages;
  • Bug fixes.

[0.1.0] - 2019-08-08

  • Initial release.


example #

A new Flutter project.

Getting Started #

This project is a starting point for a Flutter application.

A few resources to get you started if this is your first Flutter project:

For help getting started with Flutter, view our online documentation, which offers tutorials, samples, guidance on mobile development, and a full API reference.

Use this package as a library

1. Depend on it

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

  tradutor: ^0.5.1

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.

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Learn more about scoring.

We analyzed this package on Oct 16, 2019, and provided a score, details, and suggestions below. Analysis was completed with status completed using:

  • Dart: 2.5.1
  • pana: 0.12.21
  • Flutter: 1.9.1+hotfix.4


Detected platforms: Flutter

References Flutter, and has no conflicting libraries.


Package Constraint Resolved Available
Direct dependencies
Dart SDK >=2.3.0 <3.0.0
ansicolor ^1.0.2 1.0.2
args ^1.5.2 1.5.2
dart_style ^1.2.9 1.3.1
flutter 0.0.0
flutter_localizations 0.0.0
path ^1.6.2 1.6.4
stream_transform ^0.0.19 0.0.19
yaml ^2.1.16 2.2.0
Transitive dependencies
analyzer 0.38.5
async 2.4.0
charcode 1.1.2
collection 1.14.11 1.14.12
convert 2.1.1
crypto 2.1.3
csslib 0.16.1
front_end 0.1.27
glob 1.2.0
html 0.14.0+3
intl 0.15.8 0.16.0
js 0.6.1+1
kernel 0.3.27
meta 1.1.7
node_interop 1.0.3
node_io 1.0.1+2
package_config 1.1.0
pedantic 1.8.0+1
pub_semver 1.4.2
sky_engine 0.0.99
source_span 1.5.5
string_scanner 1.0.5
term_glyph 1.1.0
typed_data 1.1.6
vector_math 2.0.8
watcher 0.9.7+12
Dev dependencies