Initial commit

.gitignore

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+# Files and directories created by pub
+.dart_tool/
+.packages
+.idea
+*.iml
+# Remove the following pattern if you wish to check in your lock file
+pubspec.lock
+*.i18n.dart
+
+# Conventional directory for build outputs
+build/
+
+# Directory created by dartdoc
+doc/api/

CHANGELOG.md

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+## 0.8.5
+
+- Initial fork from original library

LICENSE

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+MIT License
+
+Copyright (c) 2019 fnx.io
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

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+Simple internationalization package for Dart and Flutter.
+
+# Overview
+
+Write your messages into YAML files, and let this package generate
+convenient Dart classes from those files.
+
+Turn this **YAML** file:
+
+    lib/exampleMessages.i18n.yaml
+    
+    button:
+      save: Save
+      load: Load
+    users:
+      welcome(String name): "Hello $name!"
+      logout: Logout
+  
+Into these **generated** Dart classes:
+
+    class ExampleMessages {
+        const ExampleMessages();
+        ButtonExampleMessages get button => ButtonExampleMessages(this);
+        UsersExampleMessages get users => UsersExampleMessages(this);
+    }
+    class ButtonExampleMessages {
+        final ExampleMessages _parent;
+        const ButtonExampleMessages(this._parent);
+        String get save => "Save";
+        String get load => "Load";
+    }
+    class UsersExampleMessages {
+        final ExampleMessages _parent;
+        const UsersExampleMessages(this._parent);
+        String get logout => "Logout";
+        String welcome(String name) => "Hello $name!";
+    }
+
+... and **use them** in your code - plain and simple.
+
+    ExampleMessages m = ExampleMessages();
+    print(m.users.welcome('World'));
+    // outputs: Hello World!
+
+Package is an extension (custom builder) for [build_runner](https://pub.dartlang.org/packages/build_runner)
+(Dart standard for source generation) and it can be used with Flutter, AngularDart
+or any other type of Dart project.
+
+# i18n: 51 points simpler than your standard i18n!
+
+## Motivation and goals
+
+* The official Dart/Flutter approach to i18n seems to be ... complicated and kind of ... heavyweight.
+* I would like my messages to be **checked during compile time**. Is that message really there?
+* Key to the localized message shouldn't be just some arbitrary String, it should be a **getter method**!
+* And if the message takes some **parameters**, the method should take those parameters! 
+* I like to bundle messages into thematic groups, the i18n tool should support that and help me with it.
+* Dart has awesome **string interpolation**, I want to leverage that!
+* I like build_runner and code generation.
+* I love the name. i18n is hilarious.
+
+## Solution
+
+Write your messages into a YAML file:
+
+    exampleMessages.i18n.yaml (default messages):
+    
+    generic:
+      ok: OK
+      done: DONE
+    invoice:
+      create: Create invoice
+      delete: Delete invoice
+  
+  
+Write your translations into other YAML files:
+
+    exampleMessages_cs.i18n.yaml (_cs = Czech translation)
+    
+    generic:    
+      done: Hotovo
+    invoice:
+      create: Vytvořit fakturu
+      delete: Smazat fakturu
+  
+... run the `webdev` tool, or `build_runner` directly, and use your messages like this:
+
+    ExampleMessages m = ExampleMessages();
+    print(m.generic.ok); // output: OK
+    print(m.generic.done); // output: DONE
+    
+    m = ExampleMessages_cs();
+    print(m.generic.ok); // output: OK
+    print(m.generic.done); // output: Hotovo
+    
+## Parameters and pluralization
+
+The implementation is VERY straightforward, which allows you to do all sorts of crazy stuff:
+
+    invoice:
+      create: Create invoice
+      delete: Delete invoice
+      help: "Use this function
+      to generate new invoices and stuff.
+      Awesome!"
+      count(int cnt): "You have created $cnt ${_plural(cnt, one:'invoice', many:'invoices')}."
+    apples:
+      _apples(int cnt): "${_plural(cnt, one:'apple', many:'apples')}"
+      count(int cnt): "You have eaten $cnt ${_apples(cnt)}."
+      
+Now see the generated classes: 
+
+    class ExampleMessages {
+        const ExampleMessages();
+        InvoiceExampleMessages get invoice => InvoiceExampleMessages(this);        
+        ApplesExampleMessages get apples => ApplesExampleMessages(this);
+    }
+        
+    class InvoiceExampleMessages {
+        final ExampleMessages _parent;
+        const InvoiceExampleMessages(this._parent);
+        String get create => "Create invoice";
+        String get help => "Use this function to generate new invoices and stuff. Awesome!";
+        String get delete => "Delete invoice";
+        String count(int cnt) => "You have created $cnt ${_plural(cnt, one:'invoice', many:'invoices')}.";
+    }
+    
+    class ApplesExampleMessages {
+        final ExampleMessages _parent;
+        const ApplesExampleMessages(this._parent);
+        String _apples(int cnt) => "${_plural(cnt, one:'apple', many:'apples')}";
+        String count(int cnt) => "You have eaten $cnt ${_apples(cnt)}.";
+    }         
+    
+See how you can **reuse** the pluralization of `_apples(int cnt)`? (nice!)
+
+There are three functions you can use in your message:
+
+    String _plural(int count, {String zero, String one, String two, String few, String many, String other})
+
+    String _cardinal(int count, {String zero, String one, String two, String few, String many, String other})
+
+    String _ordinal(int count, {String zero, String one, String two, String few, String many, String other})
+
+`_plural` and `_cardinal` do the same. I just felt that `_plural`
+ is a little bit less scary name :-)
+
+We need only two forms of the word "apple" in English. "Apple" (one) and "apples" (many).
+But in Czech, we need three:
+
+    apples:
+      _apples(int cnt): "${_plural(cnt, one:'jablko', few: 'jablka', many:'jablek')}"
+ 
+See also:
+
+* http://cldr.unicode.org/index/cldr-spec/plural-rules
+* https://www.unicode.org/cldr/charts/latest/supplemental/language_plural_rules.html
+
+## How to use generated classes
+
+How to decide what translation to use (ExampleMessages_cs?, ExampleMessages_hu?) **is up to you**.
+The package simply generates message classes, that's all.
+
+    import 'exampleMessages.i18n.dart';
+    import 'exampleMessages_cs.i18n.dart' deferred as cs;
+    
+    void main() async {
+      ExampleMessages m = ExampleMessages();
+      print(m.apples.count(1));
+      print(m.apples.count(2));
+      print(m.apples.count(5));
+    
+      await cs.loadLibrary();
+      m = cs.ExampleMessages_cs(); // see? ExampleMessages_cs extends ExampleMessages
+      print(m.apples.count(1));
+      print(m.apples.count(2));
+      print(m.apples.count(5));    
+    }    
+                      
+Where and how to store instances of these message classes - 
+again, **up to you**. I would consider ScopedModel for Flutter and registering
+messages instance into dependency injection in AngularDart.
+
+But in this case a singleton would be acceptable also.
+
+## How to use with Flutter
+
+Create YAML file with your messages, for example:
+
+    lib/messages/foo.i18n.yaml
+
+Add `build_runner` as a dev_dependency and `i18n` as a dependency to `pubspec.yaml`:
+
+    dependencies:
+      flutter:
+        sdk: flutter
+      i18n: any
+      ...
+    
+    dev_dependencies:
+      build_runner: any
+      flutter_test:
+        sdk: flutter
+ 
+Open a terminal and in the root of your Flutter project run:
+
+    flutter packages pub run build_runner watch
+    
+... and keep it running. Your message classes will appear next to YAML files and will be
+rebuilt automatically each time you change the source YAML.
+
+For one-time (re)build of your messages run:
+
+    flutter packages pub run build_runner build
+   
+Import generated messages and use them:
+
+    import 'packages:my_app/messages/foo.i18n.dart'
+    
+    ...
+    
+    Foo m = Foo();
+    return Text(m.bar);
+    ...
+    
+## How to use with AngularDart
+
+You are probably using `webdev` tool already, so you just need to add `i18n`
+ as a dependency and **that's all**.          
+
+## Custom pluralization
+
+The package can correctly decide between 'one', 'few', 'many', etc. only for
+English and Czech (for now). But you can easily plug your own language,
+see [example/main.dart](example/main.dart)
+and [Czech](lib/src/cs.dart) and [English](lib/src/en.dart)
+implementation.
+
+If you implement support for your language, please let me know,
+ I'll gladly embed it into the package. 
+ 
+# TODO
+
+* More detailed docs.
+* Use it in some of our projects for real.
+* Current limitation: default language must be english
+* TODO: support custom imports 
+
+# Example
+
+See [example](example). Clone the package repository ([https://github.com/fnx-io/i18n](https://github.com/fnx-io/i18n)) and run:
+
+    webdev serve example:8080
+
+or
+
+    pub run build_runner serve example:8080
+
+Now open the browser http://localhost:8080/ and watch the dev tools console.
+
+# Credits
+
+Created by [https://fnx.io](https://fnx.io).

analysis_options.yaml

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+# Defines a default set of lint rules enforced for
+# projects at Google. For details and rationale,
+# see https://github.com/dart-lang/pedantic#enabled-lints.
+include: package:pedantic/analysis_options.yaml
+
+# For lint rules and documentation, see http://dart-lang.github.io/linter/lints.
+# Uncomment to specify additional rules.
+# linter:
+#   rules:
+#     - camel_case_types
+
+analyzer:
+#   exclude:
+#     - path/to/excluded/files/**

build.yaml

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+# Read about `build.yaml` at https://pub.dartlang.org/packages/build_config
+builders:
+
+  yamlBasedBuilder:
+    import: "package:i18n/builder.dart"
+    builder_factories: ["yamlBasedBuilder"]
+    build_extensions: {".i69n.yaml": [".i18n.dart"]}
+    build_to: source
+    auto_apply: root_package

example/exampleMessages.i18n.yaml

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+generic:
+  ok: OK
+  done: DONE
+invoice:
+  create: Create invoice
+  delete: Delete invoice
+  help: "Use this function
+  to generate new invoices and stuff.
+  Awesome!"
+  count(int cnt): "You have created $cnt ${_plural(cnt, one:'invoice', many:'invoices')}."
+apples:
+  _apples(int cnt): "${_plural(cnt, one:'apple', many:'apples')}"
+  count(int cnt): "You have eaten $cnt ${_apples(cnt)}."

example/exampleMessages_cs.i18n.yaml

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+generic:
+  done: Hotovo
+invoice:
+  create: Vytvořit fakturu
+  delete: Smazat fakturu
+  help: "Tuhle funkci použij
+  na vytváření faktur.
+  Boží!"
+  count(int a): "Už jsi vytvořil ${_plural(a, one:'fakturu', few:'faktury', many:'faktur')}."
+apples:
+  _apples(int cnt): "${_plural(cnt, one:'jablko', few: 'jablka', many:'jablek')}"
+  count(int cnt): "Snědl jsi $cnt ${_apples(cnt)}."

example/index.html

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+<!DOCTYPE html>
+<html>
+<body>
+<p>Open the dev tools console ...</p>
+<script src="main.dart.js"></script>
+</body>
+</html>

example/main.dart

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+// Copyright (c) 2018, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+import 'package:i18n/i18n.dart' as i18n;
+
+import 'exampleMessages.i18n.dart';
+import 'exampleMessages_cs.i18n.dart' deferred as cs;
+
+void main() async {
+  print("Hello from i18n!");
+  print("Some english:");
+  ExampleMessages m = ExampleMessages();
+  print(m.generic.ok);
+  print(m.generic.done);
+  print(m.invoice.help);
+  print(m.apples.count(1));
+  print(m.apples.count(2));
+  print(m.apples.count(5));
+
+  print("Asynchronous load of Czech messages:");
+  await cs.loadLibrary();
+  print("Some czech:");
+  m = cs.ExampleMessages_cs();
+  print(m.generic.ok); // inherited from default
+  print(m.generic.done);
+  print(m.invoice.help);
+  print(m.apples.count(1));
+  print(m.apples.count(2));
+  print(m.apples.count(5));
+
+  // Override plurals for Czech or register support for your own language:
+  i18n.registerResolver("cs", (int count, i18n.QuantityType type) {
+    if (type == i18n.QuantityType.cardinal && count == 1) {
+      return i18n.QuantityCategory.one;
+    }
+    return i18n.QuantityCategory.other;
+  });
+
+  // See:
+  // http://cldr.unicode.org/index/cldr-spec/plural-rules
+  // https://www.unicode.org/cldr/charts/latest/supplemental/language_plural_rules.html
+}

lib/builder.dart

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+// Copyright (c) 2018, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'package:build/build.dart';
+import 'package:i18n/src/i18n_impl.dart';
+
+Builder yamlBasedBuilder(BuilderOptions options) => YamlBasedBuilder();
+
+class YamlBasedBuilder implements Builder {
+  @override
+  Future build(BuildStep buildStep) async {
+    // Each [buildStep] has a single input.
+    var inputId = buildStep.inputId;
+
+    // Create a new target [AssetId] based on the old one.
+    var contents = await buildStep.readAsString(inputId);
+
+    var objectName = generateMessageObjectName(inputId.pathSegments.last);
+    var dartContent = generateDartContentFromYaml(objectName, contents);
+
+    var copy = inputId.changeExtension(".dart");
+
+    // Write out the new asset.
+    await buildStep.writeAsString(copy, dartContent);
+  }
+
+  @override
+  final buildExtensions = const {
+    ".i18n.yaml": [".i18n.dart"]
+  };
+}

lib/i18n.dart

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+import 'src/cs.dart' as cs;
+import 'src/en.dart' as en;
+
+///
+/// Language specific function, which is provided with a number and should return one of possible categories.
+/// count is never null.
+///
+typedef QuantityCategory CategoryResolver(int count, QuantityType type);
+
+enum QuantityCategory { zero, one, two, few, many, other }
+
+enum QuantityType { cardinal, ordinal }
+
+void registerResolver(String languageCode, CategoryResolver resolver) {
+  _resolverRegistry[languageCode] = resolver;
+}
+
+///
+/// Same as ordinal.
+///
+String plural(int count, String languageCode, {String zero, String one, String two, String few, String many, String other}) {
+  return _resolvePlural(count, languageCode, QuantityType.cardinal, zero: zero, one: one, two: two, few: few, many: many, other: other);
+}
+
+///
+/// See: http://cldr.unicode.org/index/cldr-spec/plural-rules
+///
+String cardinal(int count, String languageCode, {String zero, String one, String two, String few, String many, String other}) {
+  return _resolvePlural(count, languageCode, QuantityType.cardinal, zero: zero, one: one, two: two, few: few, many: many, other: other);
+}
+
+///
+/// See: http://cldr.unicode.org/index/cldr-spec/plural-rules
+///
+String ordinal(int count, String languageCode, {String zero, String one, String two, String few, String many, String other}) {
+  return _resolvePlural(count, languageCode, QuantityType.ordinal, zero: zero, one: one, two: two, few: few, many: many, other: other);
+}
+
+Map<String, CategoryResolver> _resolverRegistry = {
+  "en": en.quantityResolver,
+  "cs": cs.quantityResolver,
+};
+
+String _resolvePlural(int count, String languageCode, QuantityType type, {String zero, String one, String two, String few, String many, String other}) {
+  QuantityCategory c = _resolveCategory(languageCode, count, type);
+  if (c == null) c = QuantityCategory.other;
+  if (many == null) many = other;
+  switch (c) {
+    case QuantityCategory.zero:
+      return _firstNotNull(zero, many);
+    case QuantityCategory.one:
+      return _firstNotNull(one, many);
+    case QuantityCategory.two:
+      return _firstNotNull(two, many);
+    case QuantityCategory.few:
+      return _firstNotNull(few, many);
+    case QuantityCategory.many:
+      return _firstNotNull(many, other);
+    case QuantityCategory.other:
+      return _firstNotNull(other, many);
+  }
+  return "???";
+}
+
+QuantityCategory _defaultResolver(int count, QuantityType type) {
+  switch (count) {
+    case 0:
+      return QuantityCategory.zero;
+    case 1:
+      return QuantityCategory.one;
+    case 2:
+      return QuantityCategory.two;
+    case 3:
+      return QuantityCategory.few;
+    case 4:
+      return QuantityCategory.few;
+  }
+  return QuantityCategory.other;
+}
+
+QuantityCategory _resolveCategory(String languageCode, int count, QuantityType type) {
+  if (count == null) return QuantityCategory.other;
+  CategoryResolver resolver;
+  if (languageCode != null) {
+    resolver = _resolverRegistry[languageCode];
+    if (resolver == null) {
+      resolver = _defaultResolver;
+    }
+  } else {
+    resolver = _defaultResolver;
+  }
+  return resolver(count, type);
+}
+
+String _firstNotNull(String a, String b) {
+  if (a != null) return a;
+  if (b != null) return b;
+  return "???";
+}

lib/src/cs.dart

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+import 'package:i18n/i18n.dart';
+
+///
+/// Quantity category resolver for czech.
+///
+/// See:
+///
+/// https://www.unicode.org/cldr/charts/latest/supplemental/language_plural_rules.html#cs
+///
+///
+QuantityCategory quantityResolver(int count, QuantityType type) {
+  if (type == QuantityType.ordinal) return _resolveOrdinal(count);
+  return _resolveCardinal(count);
+}
+
+QuantityCategory _resolveCardinal(int count) {
+  switch (count) {
+    case 1:
+      return QuantityCategory.one;
+    case 2:
+      return QuantityCategory.few;
+    case 3:
+      return QuantityCategory.few;
+    case 4:
+      return QuantityCategory.few;
+  }
+  return QuantityCategory.other;
+}
+
+QuantityCategory _resolveOrdinal(int count) {
+  return QuantityCategory.other;
+}

lib/src/en.dart

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+import 'package:i18n/i18n.dart';
+
+///
+/// Quantity category resolver for english.
+///
+/// See:
+///
+/// https://www.unicode.org/cldr/charts/latest/supplemental/language_plural_rules.html#en
+///
+///
+QuantityCategory quantityResolver(int count, QuantityType type) {
+  if (type == QuantityType.ordinal) return _resolveOrdinal(count);
+  return _resolveCardinal(count);
+}
+
+QuantityCategory _resolveCardinal(int count) {
+  switch (count) {
+    case 1:
+      return QuantityCategory.one;
+  }
+  return QuantityCategory.other;
+}
+
+QuantityCategory _resolveOrdinal(int count) {
+  int mod10 = count % 10;
+  int mod100 = count % 100;
+  if (mod10 == 1 && mod100 != 11) return QuantityCategory.one;
+  if (mod10 == 2 && mod100 != 12) return QuantityCategory.two;
+  if (mod10 == 3 && mod100 != 13) return QuantityCategory.few;
+  return QuantityCategory.other;
+}

lib/src/i18n_impl.dart

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+library i18n;
+
+import 'package:yaml/yaml.dart';
+
+part 'model.dart';
+
+Pattern twoCharsLower = RegExp("^[a-z]{2}\$");
+Pattern twoCharsUpper = RegExp("^[A-Z]{2}\$");
+
+String generateDartContentFromYaml(ClassMeta meta, String yamlContent) {
+  YamlMap messages = loadYaml(yamlContent);
+
+  List<TodoItem> todoList = [];
+
+  prepareTodoList(todoList, messages, meta);
+
+  StringBuffer output = StringBuffer();
+
+  output.writeln("// GENERATED FILE, do not edit!");
+  output.writeln("import 'package:i18n/i18n.dart' as i18n;");
+  if (meta.defaultFileName != null) {
+    output.writeln("import '${meta.defaultFileName}';");
+  }
+  output.writeln("");
+  output.writeln("String get _languageCode => '${meta.languageCode}';");
+  output.writeln("String get _localeName => '${meta.localeName}';");
+  output.writeln("");
+  output.writeln("String _plural(int count, {String zero, String one, String two, String few, String many, String other}) =>");
+  output.writeln("\ti18n.plural(count, _languageCode, zero:zero, one:one, two:two, few:few, many:many, other:other);");
+  output.writeln("String _ordinal(int count, {String zero, String one, String two, String few, String many, String other}) =>");
+  output.writeln("\ti18n.ordinal(count, _languageCode, zero:zero, one:one, two:two, few:few, many:many, other:other);");
+  output.writeln("String _cardinal(int count, {String zero, String one, String two, String few, String many, String other}) =>");
+  output.writeln("\ti18n.cardinal(count, _languageCode, zero:zero, one:one, two:two, few:few, many:many, other:other);");
+  output.writeln("");
+
+  for (var todo in todoList) {
+    renderTodoItem(todo, output);
+    output.writeln("");
+  }
+
+  return output.toString();
+}
+
+ClassMeta generateMessageObjectName(String fileName) {
+  String name = fileName.replaceAll(".i18n.yaml", "");
+
+  List<String> nameParts = name.split("_");
+  if (nameParts.isEmpty) {
+    throw Exception(_renderFileNameError(name));
+  }
+
+  ClassMeta result = ClassMeta();
+
+  result.defaultObjectName = _firstCharUpper(nameParts[0]);
+
+  if (nameParts.length == 1) {
+    result.objectName = result.defaultObjectName;
+    result.isDefault = true;
+    result.languageCode = "en";
+    result.localeName = "en";
+    return result;
+  } else {
+    result.defaultFileName = "${nameParts[0]}.i18n.dart";
+    result.isDefault = false;
+
+    if (nameParts.length > 3) {
+      throw Exception(_renderFileNameError(name));
+    }
+    if (nameParts.length >= 2) {
+      String languageCode = nameParts[1];
+      if (twoCharsLower.allMatches(languageCode).length != 1) {
+        throw Exception("Wrong language code '$languageCode' in file name '$fileName'. Language code must match $twoCharsLower");
+      }
+      result.languageCode = languageCode;
+      result.localeName = languageCode;
+    }
+    if (nameParts.length == 3) {
+      String countryCode = nameParts[2];
+      if (twoCharsUpper.allMatches(countryCode).length != 1) {
+        throw Exception("Wrong country code '$countryCode' in file name '$fileName'. Country code must match $twoCharsUpper");
+      }
+      result.localeName = "${result.languageCode}_${countryCode}";
+    }
+    result.objectName = "${result.defaultObjectName}_${result.localeName}";
+    return result;
+  }
+}
+
+void renderTodoItem(TodoItem todo, StringBuffer output) {
+  var meta = todo.meta;
+  YamlMap content = todo.content;
+  if (meta.isDefault) {
+    output.writeln("class ${meta.objectName} {");
+  } else {
+    output.writeln("class ${meta.objectName} extends ${meta.defaultObjectName} {");
+  }
+
+  if (meta.parent == null) {
+    output.writeln("\tconst ${meta.objectName}();");
+  } else {
+    output.writeln("\tfinal ${meta.parent.objectName} _parent;");
+    if (meta.isDefault) {
+      output.writeln("\tconst ${meta.objectName}(this._parent);");
+    } else {
+      output.writeln("\tconst ${meta.objectName}(this._parent):super(_parent);");
+    }
+  }
+  content.forEach((k, v) {
+    if (v is YamlMap) {
+      String prefix = _firstCharUpper(k);
+      ClassMeta child = meta.nest(prefix);
+      output.writeln("\t${child.objectName} get ${k} => ${child.objectName}(this);");
+    } else {
+      if (k.contains("(")) {
+        // function
+        output.writeln('\tString ${k} => "${v}";');
+      } else {
+        output.writeln('\tString get ${k} => "${v}";');
+      }
+    }
+  });
+  output.writeln("}");
+}
+
+void prepareTodoList(List<TodoItem> todoList, YamlMap messages, ClassMeta name) {
+  TodoItem todo = TodoItem(name, messages);
+  todoList.add(todo);
+
+  messages.forEach((k, v) {
+    if (v is YamlMap) {
+      String prefix = _firstCharUpper(k);
+      prepareTodoList(todoList, v, name.nest(prefix));
+    }
+  });
+}
+
+String _firstCharUpper(String s) {
+  return s.replaceRange(0, 1, s[0].toUpperCase());
+}
+
+String _renderFileNameError(String name) {
+  return "Wrong file name: '$name'";
+}

lib/src/model.dart

@@ -0,0 +1,29 @@
+part of i18n;
+
+class ClassMeta {
+  ClassMeta parent;
+  bool isDefault;
+  String defaultObjectName;
+  String defaultFileName;
+  String objectName;
+  String localeName;
+  String languageCode;
+
+  ClassMeta nest(String namePrefix) {
+    ClassMeta result = ClassMeta();
+    result.parent = this;
+    result.isDefault = isDefault;
+    result.defaultObjectName = "${namePrefix}${defaultObjectName}";
+    result.objectName = "${namePrefix}${objectName}";
+    result.localeName = localeName;
+    result.languageCode = languageCode;
+    return result;
+  }
+}
+
+class TodoItem {
+  ClassMeta meta;
+  YamlMap content;
+
+  TodoItem(this.meta, this.content);
+}

pubspec.yaml

@@ -0,0 +1,21 @@
+name: i18n
+description: Simple internationalization tool for Dart and Flutter, based on YAML files and source generation.
+version: 0.8.5
+homepage: https://github.com/MohiuddinM/i18n
+author: Muhammad Mohiuddin <muhammad.mohiuddin@live.com>
+
+environment:
+  sdk: '>=2.1.0 <3.0.0'
+
+dependencies:
+  build: ^1.0.0
+  # Not imported in code, but used to constrain `build.yaml` requirements
+  build_config: ^0.3.0
+  yaml: ^2.1.15
+
+dev_dependencies:
+  pedantic: ^1.0.0
+  test: ^1.0.0
+  build_runner: ^1.0.0
+  build_web_compilers: ^1.0.0
+

test/i18n_test.dart

@@ -0,0 +1,80 @@
+import 'package:i18n/i18n.dart';
+import 'package:i18n/src/i18n_impl.dart';
+import 'package:test/test.dart';
+import 'package:yaml/yaml.dart';
+
+void main() {
+  group('Messages meta data', () {
+    testMeta("messages", isDefault: true, defaultObjectName: "Messages", objectName: "Messages", languageCode: "en", localeName: "en");
+    testMeta("messages_cs", isDefault: false, defaultObjectName: "Messages", objectName: "Messages_cs", languageCode: "cs", localeName: "cs");
+
+    testMeta("domainMessages", isDefault: true, defaultObjectName: "DomainMessages", objectName: "DomainMessages", languageCode: "en", localeName: "en");
+    testMeta("domainMessages_cs", isDefault: false, defaultObjectName: "DomainMessages", objectName: "DomainMessages_cs", languageCode: "cs", localeName: "cs");
+    testMeta("domainMessages_cs_CZ",
+        isDefault: false, defaultObjectName: "DomainMessages", objectName: "DomainMessages_cs_CZ", languageCode: "cs", localeName: "cs_CZ");
+  });
+
+  group('Plurals', () {
+    test('en', () {
+      expect(plural(1, "en", one: "ONE!", few: "FEW!", other: "OTHER!"), equals("ONE!"));
+      expect(plural(2, "en", one: "ONE!", few: "FEW!", other: "OTHER!"), equals("OTHER!"));
+      expect(plural(3, "en", one: "ONE!", few: "FEW!", other: "OTHER!"), equals("OTHER!"));
+      expect(plural(10, "en", one: "ONE!", few: "FEW!", other: "OTHER!"), equals("OTHER!"));
+    });
+
+    test('cs', () {
+      expect(plural(1, "cs", one: "ONE!", few: "FEW!", other: "OTHER!"), equals("ONE!"));
+      expect(plural(2, "cs", one: "ONE!", few: "FEW!", other: "OTHER!"), equals("FEW!"));
+      expect(plural(3, "cs", one: "ONE!", few: "FEW!", other: "OTHER!"), equals("FEW!"));
+      expect(plural(10, "cs", one: "ONE!", few: "FEW!", other: "OTHER!"), equals("OTHER!"));
+    });
+  });
+
+  group('Message building', () {
+    test('Todo list', () {
+      ClassMeta root = new ClassMeta();
+      root.objectName = "Test";
+      root.defaultObjectName = "Test";
+      List<TodoItem> todoList = [];
+      var yaml = "foo:\n"
+          "  subfoo: subbar\n"
+          "  subfoo2: subbar2\n"
+          "other: maybe\n"
+          "or:\n"
+          "  status:\n"
+          "    name: not\n";
+
+      prepareTodoList(todoList, loadYaml(yaml), root);
+      todoList.sort((a, b) {
+        return a.meta.objectName.compareTo(b.meta.objectName);
+      });
+      expect(todoList.length, equals(4));
+      expect(todoList[0].meta.objectName, equals("FooTest"));
+      expect(todoList[1].meta.objectName, equals("OrTest"));
+      expect(todoList[2].meta.objectName, equals("StatusOrTest"));
+      expect(todoList[2].meta.parent, equals(todoList[1].meta));
+      expect(todoList[2].meta.parent.parent, equals(todoList[3].meta));
+      expect(todoList[3].meta.objectName, equals("Test"));
+      expect(todoList[3].meta.parent, isNull);
+    });
+  });
+}
+
+void testMeta(String name, {bool isDefault, String defaultObjectName, String objectName, String languageCode, String localeName}) {
+  ClassMeta meta = generateMessageObjectName(name);
+  test('$name: isDefault', () {
+    expect(meta.isDefault, equals(isDefault));
+  });
+  test('$name: defaultObjectName', () {
+    expect(meta.defaultObjectName, equals(defaultObjectName));
+  });
+  test('$name: objectName', () {
+    expect(meta.objectName, equals(objectName));
+  });
+  test('$name: localeName', () {
+    expect(meta.localeName, equals(localeName));
+  });
+  test('$name: languageCode', () {
+    expect(meta.languageCode, equals(languageCode));
+  });
+}