intl_translation/lib/generate_localized.dart - third_party/dart-pkg - Git at Google

 // Copyright (c) 2013, 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.

 /// This provides utilities for generating localized versions of
 /// messages. It does not stand alone, but expects to be given
 /// TranslatedMessage objects and generate code for a particular locale
 /// based on them.
 ///
 /// An example of usage can be found
 /// in test/message_extract/generate_from_json.dart
 library generate_localized;

 import 'package:intl/intl.dart';
 import 'src/intl_message.dart';
 import 'dart:convert';
 import 'dart:io';
 import 'package:path/path.dart' as path;

 class MessageGeneration {
   /// If the import path following package: is something else, modify the
   /// [intlImportPath] variable to change the import directives in the generated
   /// code.
   var intlImportPath = 'intl';

   /// If the path to the generated files is something other than the current
   /// directory, update the [generatedImportPath] variable to change the import
   /// directives in the generated code.
   var generatedImportPath = '';

   /// Given a base file, return the file prefixed with the path to import it.
   /// By default, that is in the current directory, but if [generatedImportPath]
   /// has been set, then use that as a prefix.
   String importForGeneratedFile(String file) =>
       generatedImportPath.isEmpty ? file : "$generatedImportPath/$file";

   /// A list of all the locales for which we have translations. Code that does
   /// the reading of translations should add to this.
   List<String> allLocales = [];

   /// If we have more than one set of messages to generate in a particular
   /// directory we may want to prefix some to distinguish them.
   String generatedFilePrefix = '';

   /// Should we use deferred loading for the generated libraries.
   bool useDeferredLoading = true;

   /// The mode to generate in - either 'release' or 'debug'.
   ///
   /// In release mode, a missing translation is an error. In debug mode, it
   /// falls back to the original string.
   String codegenMode;

   /// What is the path to the package for which we are generating.
   ///
   /// The exact format of this string depends on the generation mechanism,
   /// so it's left undefined.
   String package;

   get releaseMode => codegenMode == 'release';

   bool get jsonMode => false;

   /// Holds the generated translations.
   StringBuffer output = new StringBuffer();

   void clearOutput() {
     output = new StringBuffer();
   }

   /// Generate a file <[generated_file_prefix]>_messages_<[locale]>.dart
   /// for the [translations] in [locale] and put it in [targetDir].
   void generateIndividualMessageFile(String basicLocale,
       Iterable<TranslatedMessage> translations, String targetDir) {
     clearOutput();
     var locale = new MainMessage()
         .escapeAndValidateString(Intl.canonicalizedLocale(basicLocale));
     output.write(prologue(locale));
     // Exclude messages with no translation and translations with no matching
     // original message (e.g. if we're using some messages from a larger
     // catalog)
     var usableTranslations = translations
         .where((each) => each.originalMessages != null && each.message != null)
         .toList();
     for (var each in usableTranslations) {
       for (var original in each.originalMessages) {
         original.addTranslation(locale, each.message);
       }
     }
     usableTranslations.sort((a, b) =>
         a.originalMessages.first.name.compareTo(b.originalMessages.first.name));

     writeTranslations(usableTranslations, locale);

     // To preserve compatibility, we don't use the canonical version of the
     // locale in the file name.
     var filename = path.join(
         targetDir, "${generatedFilePrefix}messages_$basicLocale.dart");
     new File(filename).writeAsStringSync(output.toString());
   }

   /// Write out the translated forms.
   void writeTranslations(
       Iterable<TranslatedMessage> usableTranslations, String locale) {
     for (var translation in usableTranslations) {
       // Some messages we generate as methods in this class. Simpler ones
       // we inline in the map from names to messages.
       var messagesThatNeedMethods = translation.originalMessages
           .where((each) => _hasArguments(each))
           .toSet()
           .toList();
       for (var original in messagesThatNeedMethods) {
         output
           ..write("  ")
           ..write(
               original.toCodeForLocale(locale, _methodNameFor(original.name)))
           ..write("\n\n");
       }
     }
     output.write(messagesDeclaration);

     // Now write the map of names to either the direct translation or to a
     // method.
     var entries = (usableTranslations
             .expand((translation) => translation.originalMessages)
             .toSet()
             .toList()
               ..sort((a, b) => a.name.compareTo(b.name)))
         .map((original) =>
             '    "${original.escapeAndValidateString(original.name)}" '
             ': ${_mapReference(original, locale)}');
     output..write(entries.join(",\n"))..write("\n  };\n}\n");
   }

   /// Any additional imports the individual message files need.
   String get extraImports => '';

   String get messagesDeclaration =>
       // Includes some gyrations to prevent parts of the deferred libraries from
       // being inlined into the main one, defeating the space savings. Issue
       // 24356
       """
   final messages = _notInlinedMessages(_notInlinedMessages);
   static _notInlinedMessages(_) => <String, Function> {
 """;

   /// [generateIndividualMessageFile] for the beginning of the file,
   /// parameterized by [locale].
   String prologue(String locale) =>
       """
 // DO NOT EDIT. This is code generated via package:intl/generate_localized.dart
 // This is a library that provides messages for a $locale locale. All the
 // messages from the main program should be duplicated here with the same
 // function name.

 import 'package:$intlImportPath/intl.dart';
 import 'package:$intlImportPath/message_lookup_by_library.dart';
 $extraImports
 // ignore: unnecessary_new
 final messages = new MessageLookup();

 // ignore: unused_element
 final _keepAnalysisHappy = Intl.defaultLocale;

 // ignore: non_constant_identifier_names
 typedef MessageIfAbsent(String message_str, List args);

 class MessageLookup extends MessageLookupByLibrary {
   get localeName => '$locale';

 """ +
       (releaseMode ? overrideLookup : "");

   String overrideLookup = """
   String lookupMessage(
       String message_str, String locale, String name, List args, String meaning,
       {MessageIfAbsent ifAbsent}) {
     String failedLookup(String message_str, List args) {
       // If there's no message_str, then we are an internal lookup, e.g. an
       // embedded plural, and shouldn't fail.
       if (message_str == null) return null;
       // ignore: unnecessary_new
       throw new UnsupportedError(
           "No translation found for message '\$name',\\n"
           "  original text '\$message_str'");
     }
     return super.lookupMessage(message_str, locale, name, args, meaning,
         ifAbsent: ifAbsent ?? failedLookup);
   }

 """;

   /// This section generates the messages_all.dart file based on the list of
   /// [allLocales].
   String generateMainImportFile() {
     clearOutput();
     output.write(mainPrologue);
     for (var locale in allLocales) {
       var baseFile = '${generatedFilePrefix}messages_$locale.dart';
       var file = importForGeneratedFile(baseFile);
       output.write("import '$file' ");
       if (useDeferredLoading) output.write("deferred ");
       output.write("as ${libraryName(locale)};\n");
     }
     output.write("\n");
     output.write("typedef Future<dynamic> LibraryLoader();\n");
     output.write("Map<String, LibraryLoader> _deferredLibraries = {\n");
     for (var rawLocale in allLocales) {
       var locale = Intl.canonicalizedLocale(rawLocale);
       var loadOperation = (useDeferredLoading)
           ? "  '$locale': () => ${libraryName(locale)}.loadLibrary(),\n"
           : "// ignore: unnecessary_new\n"
               + "  '$locale': () => new Future.value(null),\n";
       output.write(loadOperation);
     }
     output.write("};\n");
     output.write("\nMessageLookupByLibrary _findExact(localeName) {\n"
         "  switch (localeName) {\n");
     for (var rawLocale in allLocales) {
       var locale = Intl.canonicalizedLocale(rawLocale);
       output.write(
           "    case '$locale':\n      return ${libraryName(locale)}.messages;\n");
     }
     output.write(closing);
     return output.toString();
   }

   /// Constant string used in [generateMainImportFile] for the beginning of the
   /// file.
   get mainPrologue => """
 // DO NOT EDIT. This is code generated via package:intl/generate_localized.dart
 // This is a library that looks up messages for specific locales by
 // delegating to the appropriate library.

 import 'dart:async';

 import 'package:$intlImportPath/intl.dart';
 import 'package:$intlImportPath/message_lookup_by_library.dart';
 // ignore: implementation_imports
 import 'package:$intlImportPath/src/intl_helpers.dart';

 """;

   /// Constant string used in [generateMainImportFile] as the end of the file.
   get closing => """
     default:\n      return null;
   }
 }

 /// User programs should call this before using [localeName] for messages.
 Future<bool> initializeMessages(String localeName) async {
   var availableLocale = Intl.verifiedLocale(
     localeName,
     (locale) => _deferredLibraries[locale] != null,
     onFailure: (_) => null);
   if (availableLocale == null) {
     // ignore: unnecessary_new
     return new Future.value(false);
   }
   var lib = _deferredLibraries[availableLocale];
   // ignore: unnecessary_new
   await (lib == null ? new Future.value(false) : lib());
   // ignore: unnecessary_new
   initializeInternalMessageLookup(() => new CompositeMessageLookup());
   messageLookup.addLocale(availableLocale, _findGeneratedMessagesFor);
   // ignore: unnecessary_new
   return new Future.value(true);
 }

 bool _messagesExistFor(String locale) {
   try {
     return _findExact(locale) != null;
   } catch (e) {
     return false;
   }
 }

 MessageLookupByLibrary _findGeneratedMessagesFor(locale) {
   var actualLocale = Intl.verifiedLocale(locale, _messagesExistFor,
       onFailure: (_) => null);
   if (actualLocale == null) return null;
   return _findExact(actualLocale);
 }
 """;
 }

 class JsonMessageGeneration extends MessageGeneration {
   /// We import the main file so as to get the shared code to evaluate
   /// the JSON data.
   String get extraImports => '''
 import 'dart:convert';
 import '${generatedFilePrefix}messages_all.dart' show evaluateJsonTemplate;
 ''';

   String prologue(locale) =>
       super.prologue(locale) +
       '''
   String evaluateMessage(translation, List args) {
     return evaluateJsonTemplate(translation, args);
   }
 ''';

   void writeTranslations(
       Iterable<TranslatedMessage> usableTranslations, String locale) {
     output.write(r"""
   var _messages;
   // ignore: unnecessary_new
   get messages => _messages ??= new JsonDecoder().convert(messageText);
 """);

     output.write("  static final messageText = ");
     var entries = usableTranslations
         .expand((translation) => translation.originalMessages);
     var map = {};
     for (var original in entries) {
       map[original.name] = original.toJsonForLocale(locale);
     }
     output.write(
         "r'''\n" + new JsonEncoder.withIndent('  ').convert(map) + "''';\n}");
   }

   get closing =>
       super.closing +
       '''
 /// Turn the JSON template into a string.
 ///
 /// We expect one of the following forms for the template.
 /// * null -> null
 /// * String s -> s
 /// * int n -> '\${args[n]}'
 /// * List list, one of
 ///   * \['Intl.plural', int howMany, (templates for zero, one, ...)\]
 ///   * \['Intl.gender', String gender, (templates for female, male, other)\]
 ///   * \['Intl.select', String choice, { 'case' : template, ...} \]
 ///   * \['text alternating with ', 0 , ' indexes in the argument list'\]
 String evaluateJsonTemplate(Object input, List args) {
   if (input == null) return null;
   if (input is String) return input;
   if (input is int) {
     return "\${args[input]}";
   }

   List template = input;
   var messageName = template.first;
   if (messageName == "Intl.plural") {
      var howMany = args[template[1]];
      return evaluateJsonTemplate(
          Intl.pluralLogic(
              howMany,
              zero: template[2],
              one: template[3],
              two: template[4],
              few: template[5],
              many: template[6],
              other: template[7]),
          args);
    }
    if (messageName == "Intl.gender") {
      var gender = args[template[1]];
      return evaluateJsonTemplate(
          Intl.genderLogic(
              gender,
              female: template[2],
              male: template[3],
              other: template[4]),
          args);
    }
    if (messageName == "Intl.select") {
      var select = args[template[1]];
      var choices = template[2];
      return evaluateJsonTemplate(Intl.selectLogic(select, choices), args);
    }

    // If we get this far, then we are a basic interpolation, just strings and
    // ints.
    // ignore: unnecessary_new
    var output = new StringBuffer();
    for (var entry in template) {
      if (entry is int) {
        output.write("\${args[entry]}");
      } else {
        output.write("\$entry");
      }
    }
    return output.toString();
   }

  ''';
 }

 /// This represents a message and its translation. We assume that the
 /// translation has some identifier that allows us to figure out the original
 /// message it corresponds to, and that it may want to transform the translated
 /// text in some way, e.g. to turn whatever format the translation uses for
 /// variables into a Dart string interpolation. Specific translation mechanisms
 /// are expected to subclass this.
 abstract class TranslatedMessage {
   /// The identifier for this message. In the simplest case, this is the name
   /// parameter from the Intl.message call,
   /// but it can be any identifier that this program and the output of the
   /// translation can agree on as identifying a message.
   final String id;

   /// Our translated version of all the [originalMessages].
   final Message translated;

   /// The original messages that we are a translation of. There can
   ///  be more than one original message for the same translation.
   List<MainMessage> _originalMessages;

   List<MainMessage> get originalMessages => _originalMessages;
   set originalMessages(List<MainMessage> x) {
     _originalMessages = x;
   }

   /// For backward compatibility, we still have the originalMessage API.
   MainMessage get originalMessage => originalMessages.first;
   set originalMessage(MainMessage m) {
     originalMessages = [m];
   }

   TranslatedMessage(this.id, this.translated);

   Message get message => translated;

   toString() => id.toString();

   operator ==(x) => x is TranslatedMessage && x.id == id;

   get hashCode => id.hashCode;
 }

 /// We can't use a hyphen in a Dart library name, so convert the locale
 /// separator to an underscore.
 String libraryName(String x) => 'messages_' + x.replaceAll('-', '_');

 bool _hasArguments(MainMessage message) => message.arguments.length != 0;

 ///  Simple messages are printed directly in the map of message names to
 ///  functions as a call that returns a lambda. e.g.
 ///
 ///        "foo" : simpleMessage("This is foo"),
 ///
 ///  This is helpful for the compiler.
 /// */
 String _mapReference(MainMessage original, String locale) {
   if (!_hasArguments(original)) {
     // No parameters, can be printed simply.
     return 'MessageLookupByLibrary.simpleMessage("'
         '${original.translations[locale]}")';
   } else {
     return _methodNameFor(original.name);
   }
 }

 /// Generated method counter for use in [_methodNameFor].
 int _methodNameCounter = 0;

 /// A map from Intl message names to the generated method names
 /// for their translated versions.
 Map<String, String> _internalMethodNames = {};

 /// Generate a Dart method name of the form "m<number>".
 String _methodNameFor(String name) {
   return _internalMethodNames.putIfAbsent(
       name, () => "m${_methodNameCounter++}");
 }
	// Copyright (c) 2013, 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.

	/// This provides utilities for generating localized versions of
	/// messages. It does not stand alone, but expects to be given
	/// TranslatedMessage objects and generate code for a particular locale
	/// based on them.
	///
	/// An example of usage can be found
	/// in test/message_extract/generate_from_json.dart
	library generate_localized;

	import 'package:intl/intl.dart';
	import 'src/intl_message.dart';
	import 'dart:convert';
	import 'dart:io';
	import 'package:path/path.dart' as path;

	class MessageGeneration {
	/// If the import path following package: is something else, modify the
	/// [intlImportPath] variable to change the import directives in the generated
	/// code.
	var intlImportPath = 'intl';

	/// If the path to the generated files is something other than the current
	/// directory, update the [generatedImportPath] variable to change the import
	/// directives in the generated code.
	var generatedImportPath = '';

	/// Given a base file, return the file prefixed with the path to import it.
	/// By default, that is in the current directory, but if [generatedImportPath]
	/// has been set, then use that as a prefix.
	String importForGeneratedFile(String file) =>
	generatedImportPath.isEmpty ? file : "$generatedImportPath/$file";

	/// A list of all the locales for which we have translations. Code that does
	/// the reading of translations should add to this.
	List<String> allLocales = [];

	/// If we have more than one set of messages to generate in a particular
	/// directory we may want to prefix some to distinguish them.
	String generatedFilePrefix = '';

	/// Should we use deferred loading for the generated libraries.
	bool useDeferredLoading = true;

	/// The mode to generate in - either 'release' or 'debug'.
	///
	/// In release mode, a missing translation is an error. In debug mode, it
	/// falls back to the original string.
	String codegenMode;

	/// What is the path to the package for which we are generating.
	///
	/// The exact format of this string depends on the generation mechanism,
	/// so it's left undefined.
	String package;

	get releaseMode => codegenMode == 'release';

	bool get jsonMode => false;

	/// Holds the generated translations.
	StringBuffer output = new StringBuffer();

	void clearOutput() {
	output = new StringBuffer();
	}

	/// Generate a file <[generated_file_prefix]>_messages_<[locale]>.dart
	/// for the [translations] in [locale] and put it in [targetDir].
	void generateIndividualMessageFile(String basicLocale,
	Iterable<TranslatedMessage> translations, String targetDir) {
	clearOutput();
	var locale = new MainMessage()
	.escapeAndValidateString(Intl.canonicalizedLocale(basicLocale));
	output.write(prologue(locale));
	// Exclude messages with no translation and translations with no matching
	// original message (e.g. if we're using some messages from a larger
	// catalog)
	var usableTranslations = translations
	.where((each) => each.originalMessages != null && each.message != null)
	.toList();
	for (var each in usableTranslations) {
	for (var original in each.originalMessages) {
	original.addTranslation(locale, each.message);
	}
	}
	usableTranslations.sort((a, b) =>
	a.originalMessages.first.name.compareTo(b.originalMessages.first.name));

	writeTranslations(usableTranslations, locale);

	// To preserve compatibility, we don't use the canonical version of the
	// locale in the file name.
	var filename = path.join(
	targetDir, "${generatedFilePrefix}messages_$basicLocale.dart");
	new File(filename).writeAsStringSync(output.toString());
	}

	/// Write out the translated forms.
	void writeTranslations(
	Iterable<TranslatedMessage> usableTranslations, String locale) {
	for (var translation in usableTranslations) {
	// Some messages we generate as methods in this class. Simpler ones
	// we inline in the map from names to messages.
	var messagesThatNeedMethods = translation.originalMessages
	.where((each) => _hasArguments(each))
	.toSet()
	.toList();
	for (var original in messagesThatNeedMethods) {
	output
	..write(" ")
	..write(
	original.toCodeForLocale(locale, _methodNameFor(original.name)))
	..write("\n\n");
	}
	}
	output.write(messagesDeclaration);

	// Now write the map of names to either the direct translation or to a
	// method.
	var entries = (usableTranslations
	.expand((translation) => translation.originalMessages)
	.toSet()
	.toList()
	..sort((a, b) => a.name.compareTo(b.name)))
	.map((original) =>
	' "${original.escapeAndValidateString(original.name)}" '
	': ${_mapReference(original, locale)}');
	output..write(entries.join(",\n"))..write("\n };\n}\n");
	}

	/// Any additional imports the individual message files need.
	String get extraImports => '';

	String get messagesDeclaration =>
	// Includes some gyrations to prevent parts of the deferred libraries from
	// being inlined into the main one, defeating the space savings. Issue
	// 24356
	"""
	final messages = _notInlinedMessages(_notInlinedMessages);
	static _notInlinedMessages(_) => <String, Function> {
	""";

	/// [generateIndividualMessageFile] for the beginning of the file,
	/// parameterized by [locale].
	String prologue(String locale) =>
	"""
	// DO NOT EDIT. This is code generated via package:intl/generate_localized.dart
	// This is a library that provides messages for a $locale locale. All the
	// messages from the main program should be duplicated here with the same
	// function name.

	import 'package:$intlImportPath/intl.dart';
	import 'package:$intlImportPath/message_lookup_by_library.dart';
	$extraImports
	// ignore: unnecessary_new
	final messages = new MessageLookup();

	// ignore: unused_element
	final _keepAnalysisHappy = Intl.defaultLocale;

	// ignore: non_constant_identifier_names
	typedef MessageIfAbsent(String message_str, List args);

	class MessageLookup extends MessageLookupByLibrary {
	get localeName => '$locale';

	""" +
	(releaseMode ? overrideLookup : "");

	String overrideLookup = """
	String lookupMessage(
	String message_str, String locale, String name, List args, String meaning,
	{MessageIfAbsent ifAbsent}) {
	String failedLookup(String message_str, List args) {
	// If there's no message_str, then we are an internal lookup, e.g. an
	// embedded plural, and shouldn't fail.
	if (message_str == null) return null;
	// ignore: unnecessary_new
	throw new UnsupportedError(
	"No translation found for message '\$name',\\n"
	" original text '\$message_str'");
	}
	return super.lookupMessage(message_str, locale, name, args, meaning,
	ifAbsent: ifAbsent ?? failedLookup);
	}

	""";

	/// This section generates the messages_all.dart file based on the list of
	/// [allLocales].
	String generateMainImportFile() {
	clearOutput();
	output.write(mainPrologue);
	for (var locale in allLocales) {
	var baseFile = '${generatedFilePrefix}messages_$locale.dart';
	var file = importForGeneratedFile(baseFile);
	output.write("import '$file' ");
	if (useDeferredLoading) output.write("deferred ");
	output.write("as ${libraryName(locale)};\n");
	}
	output.write("\n");
	output.write("typedef Future<dynamic> LibraryLoader();\n");
	output.write("Map<String, LibraryLoader> _deferredLibraries = {\n");
	for (var rawLocale in allLocales) {
	var locale = Intl.canonicalizedLocale(rawLocale);
	var loadOperation = (useDeferredLoading)
	? " '$locale': () => ${libraryName(locale)}.loadLibrary(),\n"
	: "// ignore: unnecessary_new\n"
	+ " '$locale': () => new Future.value(null),\n";
	output.write(loadOperation);
	}
	output.write("};\n");
	output.write("\nMessageLookupByLibrary _findExact(localeName) {\n"
	" switch (localeName) {\n");
	for (var rawLocale in allLocales) {
	var locale = Intl.canonicalizedLocale(rawLocale);
	output.write(
	" case '$locale':\n return ${libraryName(locale)}.messages;\n");
	}
	output.write(closing);
	return output.toString();
	}

	/// Constant string used in [generateMainImportFile] for the beginning of the
	/// file.
	get mainPrologue => """
	// DO NOT EDIT. This is code generated via package:intl/generate_localized.dart
	// This is a library that looks up messages for specific locales by
	// delegating to the appropriate library.

	import 'dart:async';

	import 'package:$intlImportPath/intl.dart';
	import 'package:$intlImportPath/message_lookup_by_library.dart';
	// ignore: implementation_imports
	import 'package:$intlImportPath/src/intl_helpers.dart';

	""";

	/// Constant string used in [generateMainImportFile] as the end of the file.
	get closing => """
	default:\n return null;
	}
	}

	/// User programs should call this before using [localeName] for messages.
	Future<bool> initializeMessages(String localeName) async {
	var availableLocale = Intl.verifiedLocale(
	localeName,
	(locale) => _deferredLibraries[locale] != null,
	onFailure: (_) => null);
	if (availableLocale == null) {
	// ignore: unnecessary_new
	return new Future.value(false);
	}
	var lib = _deferredLibraries[availableLocale];
	// ignore: unnecessary_new
	await (lib == null ? new Future.value(false) : lib());
	// ignore: unnecessary_new
	initializeInternalMessageLookup(() => new CompositeMessageLookup());
	messageLookup.addLocale(availableLocale, _findGeneratedMessagesFor);
	// ignore: unnecessary_new
	return new Future.value(true);
	}

	bool _messagesExistFor(String locale) {
	try {
	return _findExact(locale) != null;
	} catch (e) {
	return false;
	}
	}

	MessageLookupByLibrary _findGeneratedMessagesFor(locale) {
	var actualLocale = Intl.verifiedLocale(locale, _messagesExistFor,
	onFailure: (_) => null);
	if (actualLocale == null) return null;
	return _findExact(actualLocale);
	}
	""";
	}

	class JsonMessageGeneration extends MessageGeneration {
	/// We import the main file so as to get the shared code to evaluate
	/// the JSON data.
	String get extraImports => '''
	import 'dart:convert';
	import '${generatedFilePrefix}messages_all.dart' show evaluateJsonTemplate;
	''';

	String prologue(locale) =>
	super.prologue(locale) +
	'''
	String evaluateMessage(translation, List args) {
	return evaluateJsonTemplate(translation, args);
	}
	''';

	void writeTranslations(
	Iterable<TranslatedMessage> usableTranslations, String locale) {
	output.write(r"""
	var _messages;
	// ignore: unnecessary_new
	get messages => _messages ??= new JsonDecoder().convert(messageText);
	""");

	output.write(" static final messageText = ");
	var entries = usableTranslations
	.expand((translation) => translation.originalMessages);
	var map = {};
	for (var original in entries) {
	map[original.name] = original.toJsonForLocale(locale);
	}
	output.write(
	"r'''\n" + new JsonEncoder.withIndent(' ').convert(map) + "''';\n}");
	}

	get closing =>
	super.closing +
	'''
	/// Turn the JSON template into a string.
	///
	/// We expect one of the following forms for the template.
	/// * null -> null
	/// * String s -> s
	/// * int n -> '\${args[n]}'
	/// * List list, one of
	/// * \['Intl.plural', int howMany, (templates for zero, one, ...)\]
	/// * \['Intl.gender', String gender, (templates for female, male, other)\]
	/// * \['Intl.select', String choice, { 'case' : template, ...} \]
	/// * \['text alternating with ', 0 , ' indexes in the argument list'\]
	String evaluateJsonTemplate(Object input, List args) {
	if (input == null) return null;
	if (input is String) return input;
	if (input is int) {
	return "\${args[input]}";
	}

	List template = input;
	var messageName = template.first;
	if (messageName == "Intl.plural") {
	var howMany = args[template[1]];
	return evaluateJsonTemplate(
	Intl.pluralLogic(
	howMany,
	zero: template[2],
	one: template[3],
	two: template[4],
	few: template[5],
	many: template[6],
	other: template[7]),
	args);
	}
	if (messageName == "Intl.gender") {
	var gender = args[template[1]];
	return evaluateJsonTemplate(
	Intl.genderLogic(
	gender,
	female: template[2],
	male: template[3],
	other: template[4]),
	args);
	}
	if (messageName == "Intl.select") {
	var select = args[template[1]];
	var choices = template[2];
	return evaluateJsonTemplate(Intl.selectLogic(select, choices), args);
	}

	// If we get this far, then we are a basic interpolation, just strings and
	// ints.
	// ignore: unnecessary_new
	var output = new StringBuffer();
	for (var entry in template) {
	if (entry is int) {
	output.write("\${args[entry]}");
	} else {
	output.write("\$entry");
	}
	}
	return output.toString();
	}

	''';
	}

	/// This represents a message and its translation. We assume that the
	/// translation has some identifier that allows us to figure out the original
	/// message it corresponds to, and that it may want to transform the translated
	/// text in some way, e.g. to turn whatever format the translation uses for
	/// variables into a Dart string interpolation. Specific translation mechanisms
	/// are expected to subclass this.
	abstract class TranslatedMessage {
	/// The identifier for this message. In the simplest case, this is the name
	/// parameter from the Intl.message call,
	/// but it can be any identifier that this program and the output of the
	/// translation can agree on as identifying a message.
	final String id;

	/// Our translated version of all the [originalMessages].
	final Message translated;

	/// The original messages that we are a translation of. There can
	/// be more than one original message for the same translation.
	List<MainMessage> _originalMessages;

	List<MainMessage> get originalMessages => _originalMessages;
	set originalMessages(List<MainMessage> x) {
	_originalMessages = x;
	}

	/// For backward compatibility, we still have the originalMessage API.
	MainMessage get originalMessage => originalMessages.first;
	set originalMessage(MainMessage m) {
	originalMessages = [m];
	}

	TranslatedMessage(this.id, this.translated);

	Message get message => translated;

	toString() => id.toString();

	operator ==(x) => x is TranslatedMessage && x.id == id;

	get hashCode => id.hashCode;
	}

	/// We can't use a hyphen in a Dart library name, so convert the locale
	/// separator to an underscore.
	String libraryName(String x) => 'messages_' + x.replaceAll('-', '_');

	bool _hasArguments(MainMessage message) => message.arguments.length != 0;

	/// Simple messages are printed directly in the map of message names to
	/// functions as a call that returns a lambda. e.g.
	///
	/// "foo" : simpleMessage("This is foo"),
	///
	/// This is helpful for the compiler.
	/// */
	String _mapReference(MainMessage original, String locale) {
	if (!_hasArguments(original)) {
	// No parameters, can be printed simply.
	return 'MessageLookupByLibrary.simpleMessage("'
	'${original.translations[locale]}")';
	} else {
	return _methodNameFor(original.name);
	}
	}

	/// Generated method counter for use in [_methodNameFor].
	int _methodNameCounter = 0;

	/// A map from Intl message names to the generated method names
	/// for their translated versions.
	Map<String, String> _internalMethodNames = {};

	/// Generate a Dart method name of the form "m<number>".
	String _methodNameFor(String name) {
	return _internalMethodNames.putIfAbsent(
	name, () => "m${_methodNameCounter++}");
	}