Update Stocks example using i18n tool (#44223)

* Use l10n tool to generate stocks i18n files

* Rename *_en_EN.arb to *_en_US.arb

* Fix l10n script

analysis_options.yaml

@@ -36,7 +36,7 @@ analyzer:
     - "bin/cache/**"
     # the following two are relative to the stocks example and the flutter package respectively
     # see https://github.com/dart-lang/sdk/issues/28463
-    - "lib/i18n/stock_messages_*.dart"
+    - "lib/i18n/messages_*.dart"
     - "lib/src/http/**"
 
 linter:

dev/tools/localization/gen_l10n.dart

@@ -99,7 +99,7 @@ class _@classNameDelegate extends LocalizationsDelegate<@className> {
   Future<@className> load(Locale locale) => @className.load(locale);
 
   @override
-  bool isSupported(Locale locale) => [@supportedLanguageCodes].contains(locale.languageCode);
+  bool isSupported(Locale locale) => <String>[@supportedLanguageCodes].contains(locale.languageCode);
 
   @override
   bool shouldReload(_@classNameDelegate old) => false;
@@ -236,7 +236,7 @@ String genPluralMethod(Map<String, dynamic> bundle, String key) {
 }
 
 String genSupportedLocaleProperty(Set<LocaleInfo> supportedLocales) {
-  const String prefix = 'static const List<Locale> supportedLocales = <Locale>[ \n    Locale(''';
+  const String prefix = 'static const List<Locale> supportedLocales = <Locale>[\n    Locale(''';
   const String suffix = '),\n  ];';
 
   String resultingProperty = prefix;
@@ -289,7 +289,7 @@ bool _isDirectoryReadableAndWritable(String statString) {
 
 String _importFilePath(String path, String fileName) {
   final String replaceLib = path.replaceAll('lib/', '');
-  return '$replaceLib/$fileName.dart';
+  return '$replaceLib/$fileName';
 }
 
 Future<void> main(List<String> args) async {

examples/stocks/lib/i18n/messages_all.dart

@@ -2,28 +2,34 @@
 // This is a library that looks up messages for specific locales by
 // delegating to the appropriate library.
 
+// Ignore issues from commonly used lints in this file.
+// ignore_for_file:implementation_imports, file_names, unnecessary_new
+// ignore_for_file:unnecessary_brace_in_string_interps, directives_ordering
+// ignore_for_file:argument_type_not_assignable, invalid_assignment
+// ignore_for_file:prefer_single_quotes, prefer_generic_function_type_aliases
+// ignore_for_file:comment_references
+
 import 'dart:async';
 
 import 'package:intl/intl.dart';
 import 'package:intl/message_lookup_by_library.dart';
-// ignore: implementation_imports
 import 'package:intl/src/intl_helpers.dart';
 
-import 'stock_messages_en.dart' as messages_en;
-import 'stock_messages_es.dart' as messages_es;
+import 'messages_en_US.dart' as messages_en_us;
+import 'messages_es_ES.dart' as messages_es_es;
 
 typedef Future<dynamic> LibraryLoader();
 Map<String, LibraryLoader> _deferredLibraries = {
-  'en': () => new Future.value(null),
-  'es': () => new Future.value(null),
+  'en_US': () => new Future.value(null),
+  'es_ES': () => new Future.value(null),
 };
 
-MessageLookupByLibrary _findExact(localeName) {
+MessageLookupByLibrary _findExact(String localeName) {
   switch (localeName) {
-    case 'en':
-      return messages_en.messages;
-    case 'es':
-      return messages_es.messages;
+    case 'en_US':
+      return messages_en_us.messages;
+    case 'es_ES':
+      return messages_es_es.messages;
     default:
       return null;
   }
@@ -53,7 +59,7 @@ bool _messagesExistFor(String locale) {
   }
 }
 
-MessageLookupByLibrary _findGeneratedMessagesFor(locale) {
+MessageLookupByLibrary _findGeneratedMessagesFor(String locale) {
   var actualLocale = Intl.verifiedLocale(locale, _messagesExistFor,
       onFailure: (_) => null);
   if (actualLocale == null) return null;

examples/stocks/lib/i18n/messages_en_US.dart

@@ -1,26 +1,28 @@
 // DO NOT EDIT. This is code generated via package:intl/generate_localized.dart
-// This is a library that provides messages for a en locale. All the
+// This is a library that provides messages for a en_US locale. All the
 // messages from the main program should be duplicated here with the same
 // function name.
 
+// Ignore issues from commonly used lints in this file.
+// ignore_for_file:unnecessary_brace_in_string_interps, unnecessary_new
+// ignore_for_file:prefer_single_quotes,comment_references, directives_ordering
+// ignore_for_file:annotate_overrides,prefer_generic_function_type_aliases
+// ignore_for_file:unused_import, file_names
+
 import 'package:intl/intl.dart';
 import 'package:intl/message_lookup_by_library.dart';
 
 final messages = new MessageLookup();
 
-// ignore: unused_element
-final _keepAnalysisHappy = Intl.defaultLocale;
-
-// ignore: non_constant_identifier_names
-typedef MessageIfAbsent(String message_str, List args);
+typedef String MessageIfAbsent(String messageStr, List<dynamic> args);
 
 class MessageLookup extends MessageLookupByLibrary {
-  get localeName => 'en';
+  String get localeName => 'en_US';
 
   final messages = _notInlinedMessages(_notInlinedMessages);
   static _notInlinedMessages(_) => <String, Function> {
     "market" : MessageLookupByLibrary.simpleMessage("MARKET"),
     "portfolio" : MessageLookupByLibrary.simpleMessage("PORTFOLIO"),
-    "title" : MessageLookupByLibrary.simpleMessage("Stocks"),
+    "title" : MessageLookupByLibrary.simpleMessage("Stocks")
   };
 }

examples/stocks/lib/i18n/messages_es_ES.dart

@@ -1,26 +1,28 @@
 // DO NOT EDIT. This is code generated via package:intl/generate_localized.dart
-// This is a library that provides messages for a es locale. All the
+// This is a library that provides messages for a es_ES locale. All the
 // messages from the main program should be duplicated here with the same
 // function name.
 
+// Ignore issues from commonly used lints in this file.
+// ignore_for_file:unnecessary_brace_in_string_interps, unnecessary_new
+// ignore_for_file:prefer_single_quotes,comment_references, directives_ordering
+// ignore_for_file:annotate_overrides,prefer_generic_function_type_aliases
+// ignore_for_file:unused_import, file_names
+
 import 'package:intl/intl.dart';
 import 'package:intl/message_lookup_by_library.dart';
 
 final messages = new MessageLookup();
 
-// ignore: unused_element
-final _keepAnalysisHappy = Intl.defaultLocale;
-
-// ignore: non_constant_identifier_names
-typedef MessageIfAbsent(String message_str, List args);
+typedef String MessageIfAbsent(String messageStr, List<dynamic> args);
 
 class MessageLookup extends MessageLookupByLibrary {
-  get localeName => 'es';
+  String get localeName => 'es_ES';
 
   final messages = _notInlinedMessages(_notInlinedMessages);
   static _notInlinedMessages(_) => <String, Function> {
     "market" : MessageLookupByLibrary.simpleMessage("MERCADO"),
     "portfolio" : MessageLookupByLibrary.simpleMessage("CARTERA"),
-    "title" : MessageLookupByLibrary.simpleMessage("Acciones"),
+    "title" : MessageLookupByLibrary.simpleMessage("Acciones")
   };
 }

examples/stocks/lib/i18n/regenerate.md

@@ -1,33 +1,26 @@
-## Regenerating the i18n files
+# Regenerating the i18n files
 
-The files in this directory are based on ../lib/stock_strings.dart
-which defines all of the localizable strings used by the stocks
-app. The stocks app uses
-the [Dart `intl` package](https://github.com/dart-lang/intl).
+The files in this directory are used to generate `stock_strings.dart`, which
+is used by the stocks application to look up localized message strings. The
+stocks app uses the [Dart `intl` package](https://github.com/dart-lang/intl).
 
 Rebuilding everything requires two steps.
 
-With the `examples/stocks` as the current directory, generate
-`intl_messages.arb` from `lib/stock_strings.dart`:
-```
-flutter pub pub run intl_translation:extract_to_arb --output-dir=lib/i18n lib/stock_strings.dart
-```
-The `intl_messages.arb` file is a JSON format map with one entry for
-each `Intl.message()` function defined in `stock_strings.dart`. This
-file was used to create the English and Spanish localizations,
-`stocks_en.arb` and `stocks_es.arb`. The `intl_messages.arb` wasn't
-checked into the repository, since it only serves as a template for
-the other `.arb` files.
+1. Create or update the English and Spanish localizations, `stocks_en_US.arb`
+and `stocks_es_ES.arb`. See the [ARB specification](https://github.com/google/app-resource-bundle/wiki/ApplicationResourceBundleSpecification)
+for more info.
 
+2. With `examples/stocks` as the current directory, generate a
+`messages_<locale>.dart` for each `stocks_<locale>.arb` file,
+`messages_all.dart`, and `stock_strings.dart` with the following command:
 
-With the `examples/stocks` as the current directory, generate a
-`stock_messages_<locale>.dart` for each `stocks_<locale>.arb` file and
-`stock_messages_all.dart`, which imports all of the messages files:
-```
-flutter pub pub run intl_translation:generate_from_arb --output-dir=lib/i18n \
-   --generated-file-prefix=stock_ --no-use-deferred-loading lib/*.dart lib/i18n/stocks_*.arb
+```dart
+dart ${FLUTTER_PATH}/dev/tools/localization/gen_l10n.dart --arb-dir=lib/i18n
+  --template-arb-file=stocks_en_EN.arb --output-localization-file=stock_strings.dart
+  --output-class=StockStrings
 ```
 
-The `StockStrings` class uses the generated `initializeMessages()`
-function (`stock_messages_all.dart`) to load the localized messages
-and `Intl.message()` to look them up.
+The `StockStrings` class uses the generated `initializeMessages()`function
+(`messages_all.dart`) to load the localized messages and `Intl.message()`
+to look them up. The generated class's API documentation explains how to add
+the new localizations delegate and supported locales to the Flutter application.

examples/stocks/lib/i18n/stock_strings.dart

@@ -0,0 +1,124 @@
+import 'dart:async';
+
+import 'package:flutter/widgets.dart';
+import 'package:flutter_localizations/flutter_localizations.dart';
+import 'package:intl/intl.dart';
+
+import 'messages_all.dart';
+
+/// Callers can lookup localized strings with an instance of StockStrings returned
+/// by `StockStrings.of(context)`.
+///
+/// Applications need to include `StockStrings.delegate()` in their app's
+/// localizationDelegates list, and the locales they support in the app's
+/// supportedLocales list. For example:
+///
+/// ```
+/// import 'i18n/stock_strings.dart';
+///
+/// return MaterialApp(
+///   localizationsDelegates: StockStrings.localizationsDelegates,
+///   supportedLocales: StockStrings.supportedLocales,
+///   home: MyApplicationHome(),
+/// );
+/// ```
+///
+/// ## iOS Applications
+///
+/// iOS applications define key application metadata, including supported
+/// locales, in an Info.plist file that is built into the application bundle.
+/// To configure the locales supported by your app, you’ll need to edit this
+/// file.
+///
+/// First, open your project’s ios/Runner.xcworkspace Xcode workspace file.
+/// Then, in the Project Navigator, open the Info.plist file under the Runner
+/// project’s Runner folder.
+///
+/// Next, select the Information Property List item, select Add Item from the
+/// Editor menu, then select Localizations from the pop-up menu.
+///
+/// Select and expand the newly-created Localizations item then, for each
+/// locale your application supports, add a new item and select the locale
+/// you wish to add from the pop-up menu in the Value field. This list should
+/// be consistent with the languages listed in the StockStrings.supportedLocales
+/// property.
+
+class StockStrings {
+  StockStrings(Locale locale) : _localeName = locale.toString();
+
+  final String _localeName;
+
+  static Future<StockStrings> load(Locale locale) {
+    return initializeMessages(locale.toString())
+      .then<StockStrings>((void _) => StockStrings(locale));
+  }
+
+  static StockStrings of(BuildContext context) {
+    return Localizations.of<StockStrings>(context, StockStrings);
+  }
+
+  static const LocalizationsDelegate<StockStrings> delegate = _StockStringsDelegate();
+
+  /// A list of this localizations delegate along with the default localizations
+  /// delegates.
+  ///
+  /// Returns a list of localizations delegates containing this delegate along with
+  /// GlobalMaterialLocalizations.delegate, GlobalCupertinoLocalizations.delegate,
+  /// and GlobalWidgetsLocalizations.delegate.
+  static const List<LocalizationsDelegate<dynamic>> localizationsDelegates = <LocalizationsDelegate<dynamic>>[
+    delegate,
+    GlobalMaterialLocalizations.delegate,
+    GlobalCupertinoLocalizations.delegate,
+    GlobalWidgetsLocalizations.delegate,
+  ];
+
+  /// A list of this localizations delegate's supported locales.
+  static const List<Locale> supportedLocales = <Locale>[
+    Locale('en', 'US'),
+    Locale('es', 'ES'),
+  ];
+
+  String title() {
+    return Intl.message(
+      r'Stocks',
+      locale: _localeName,
+      name: 'title',
+      desc: 'Title for the Stocks application',
+      args: <Object>[]
+    );
+  }
+
+  String market() {
+    return Intl.message(
+      r'MARKET',
+      locale: _localeName,
+      name: 'market',
+      desc: 'Label for the Market tab',
+      args: <Object>[]
+    );
+  }
+
+  String portfolio() {
+    return Intl.message(
+      r'PORTFOLIO',
+      locale: _localeName,
+      name: 'portfolio',
+      desc: 'Label for the Portfolio tab',
+      args: <Object>[]
+    );
+  }
+
+}
+
+class _StockStringsDelegate extends LocalizationsDelegate<StockStrings> {
+  const _StockStringsDelegate();
+
+  @override
+  Future<StockStrings> load(Locale locale) => StockStrings.load(locale);
+
+  @override
+  bool isSupported(Locale locale) => <String>['en', 'es'].contains(locale.languageCode);
+
+  @override
+  bool shouldReload(_StockStringsDelegate old) => false;
+}

examples/stocks/lib/main.dart

@@ -4,8 +4,6 @@
 
 library stocks;
 
-import 'dart:async';
-
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart' show
   debugPaintSizeEnabled,
@@ -13,26 +11,14 @@ import 'package:flutter/rendering.dart' show
   debugPaintLayerBordersEnabled,
   debugPaintPointersEnabled,
   debugRepaintRainbowEnabled;
-import 'package:flutter_localizations/flutter_localizations.dart';
 
+import 'i18n/stock_strings.dart';
 import 'stock_data.dart';
 import 'stock_home.dart';
 import 'stock_settings.dart';
-import 'stock_strings.dart';
 import 'stock_symbol_viewer.dart';
 import 'stock_types.dart';
 
-class _StocksLocalizationsDelegate extends LocalizationsDelegate<StockStrings> {
-  @override
-  Future<StockStrings> load(Locale locale) => StockStrings.load(locale);
-
-  @override
-  bool isSupported(Locale locale) => locale.languageCode == 'es' || locale.languageCode == 'en';
-
-  @override
-  bool shouldReload(_StocksLocalizationsDelegate old) => false;
-}
-
 class StocksApp extends StatefulWidget {
   @override
   StocksAppState createState() => StocksAppState();
@@ -108,15 +94,8 @@ class StocksAppState extends State<StocksApp> {
     return MaterialApp(
       title: 'Stocks',
       theme: theme,
-      localizationsDelegates: <LocalizationsDelegate<dynamic>>[
-        _StocksLocalizationsDelegate(),
-        GlobalMaterialLocalizations.delegate,
-        GlobalWidgetsLocalizations.delegate,
-      ],
-      supportedLocales: const <Locale>[
-        Locale('en', 'US'),
-        Locale('es', 'ES'),
-      ],
+      localizationsDelegates: StockStrings.localizationsDelegates,
+      supportedLocales: StockStrings.supportedLocales,
       debugShowMaterialGrid: _configuration.debugShowGrid,
       showPerformanceOverlay: _configuration.showPerformanceOverlay,
       showSemanticsDebugger: _configuration.showSemanticsDebugger,

examples/stocks/lib/stock_home.dart

@@ -6,9 +6,10 @@ import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart' show debugDumpRenderTree, debugDumpLayerTree, debugDumpSemanticsTree, DebugSemanticsDumpOrder;
 import 'package:flutter/scheduler.dart' show timeDilation;
 import 'package:flutter/gestures.dart' show DragStartBehavior;
+
+import 'i18n/stock_strings.dart';
 import 'stock_data.dart';
 import 'stock_list.dart';
-import 'stock_strings.dart';
 import 'stock_symbol_viewer.dart';
 import 'stock_types.dart';
 

examples/stocks/lib/stock_strings.dart

@@ -1,53 +0,0 @@
-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-import 'dart:async';
-
-import 'package:intl/intl.dart';
-import 'package:flutter/widgets.dart';
-
-import 'i18n/stock_messages_all.dart';
-
-// Information about how this file relates to i18n/stock_messages_all.dart and how the i18n files
-// were generated can be found in i18n/regenerate.md.
-
-class StockStrings {
-  StockStrings(Locale locale) : _localeName = locale.toString();
-
-  final String _localeName;
-
-  static Future<StockStrings> load(Locale locale) {
-    return initializeMessages(locale.toString())
-      .then<StockStrings>((Object _) {
-        return StockStrings(locale);
-      });
-  }
-
-  static StockStrings of(BuildContext context) {
-    return Localizations.of<StockStrings>(context, StockStrings);
-  }
-
-  String title() {
-    return Intl.message(
-      '<Stocks>',
-      name: 'title',
-      desc: 'Title for the Stocks application',
-      locale: _localeName,
-    );
-  }
-
-  String market() => Intl.message(
-    'MARKET',
-    name: 'market',
-    desc: 'Label for the Market tab',
-    locale: _localeName,
-  );
-
-  String portfolio() => Intl.message(
-    'PORTFOLIO',
-    name: 'portfolio',
-    desc: 'Label for the Portfolio tab',
-    locale: _localeName,
-  );
-}