| // Copyright (c) 2012, 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. |
| |
| /// A library for general helper code associated with the intl library |
| /// rather than confined to specific parts of it. |
| |
| library intl_helpers; |
| |
| import 'dart:async'; |
| import 'package:intl/intl.dart'; |
| |
| /// Type for the callback action when a message translation is not found. |
| typedef MessageIfAbsent(String message_str, List args); |
| |
| /// This is used as a marker for a locale data map that hasn't been initialized, |
| /// and will throw an exception on any usage that isn't the fallback |
| /// patterns/symbols provided. |
| class UninitializedLocaleData<F> implements MessageLookup { |
| final String message; |
| final F fallbackData; |
| UninitializedLocaleData(this.message, this.fallbackData); |
| |
| operator [](String key) => |
| (key == 'en_US') ? fallbackData : _throwException(); |
| |
| /// If a message is looked up before any locale initialization, record it, |
| /// and throw an exception with that information once the locale is |
| /// initialized. |
| /// |
| /// Set this during development to find issues with race conditions between |
| /// message caching and locale initialization. If the results of Intl.message |
| /// calls aren't being cached, then this won't help. |
| /// |
| /// There's nothing that actually sets this, so checking this requires |
| /// patching the code here. |
| static final bool throwOnFallback = false; |
| |
| /// The messages that were called before the locale was initialized. |
| List<String> _badMessages = []; |
| |
| void _reportErrors() { |
| if (throwOnFallback && _badMessages.length > 0) { |
| throw new StateError( |
| "The following messages were called before locale initialization:" |
| " $_uninitializedMessages"); |
| } |
| } |
| |
| String get _uninitializedMessages => |
| (_badMessages.toSet().toList()..sort()).join("\n "); |
| |
| String lookupMessage( |
| String message_str, String locale, String name, List args, String meaning, |
| {MessageIfAbsent ifAbsent}) { |
| if (throwOnFallback) { |
| _badMessages.add(name ?? message_str); |
| } |
| return message_str; |
| } |
| |
| /// Given an initial locale or null, returns the locale that will be used |
| /// for messages. |
| String findLocale(String locale) => locale ?? Intl.getCurrentLocale(); |
| |
| List<String> get keys => _throwException() as List<String>; |
| |
| bool containsKey(String key) => (key == 'en_US') ? true : _throwException(); |
| |
| _throwException() { |
| throw new LocaleDataException("Locale data has not been initialized" |
| ", call $message."); |
| } |
| |
| void addLocale(String localeName, Function findLocale) => _throwException(); |
| } |
| |
| abstract class MessageLookup { |
| String lookupMessage( |
| String message_str, String locale, String name, List args, String meaning, |
| {MessageIfAbsent ifAbsent}); |
| void addLocale(String localeName, Function findLocale); |
| } |
| |
| class LocaleDataException implements Exception { |
| final String message; |
| LocaleDataException(this.message); |
| toString() => "LocaleDataException: $message"; |
| } |
| |
| /// An abstract superclass for data readers to keep the type system happy. |
| abstract class LocaleDataReader { |
| Future read(String locale); |
| } |
| |
| /// The internal mechanism for looking up messages. We expect this to be set |
| /// by the implementing package so that we're not dependent on its |
| /// implementation. |
| MessageLookup messageLookup = |
| new UninitializedLocaleData('initializeMessages(<locale>)', null); |
| |
| /// Initialize the message lookup mechanism. This is for internal use only. |
| /// User applications should import `message_lookup_by_library.dart` and call |
| /// `initializeMessages` |
| void initializeInternalMessageLookup(Function lookupFunction) { |
| if (messageLookup is UninitializedLocaleData) { |
| // This line has to be precisely this way to work around an analyzer crash. |
| (messageLookup as UninitializedLocaleData)._reportErrors(); |
| messageLookup = lookupFunction(); |
| } |
| } |
| |
| /// If a message is a string literal without interpolation, compute |
| /// a name based on that and the meaning, if present. |
| // NOTE: THIS LOGIC IS DUPLICATED IN intl_translation AND THE TWO MUST MATCH. |
| String computeMessageName(String name, String text, String meaning) { |
| if (name != null && name != "") return name; |
| return meaning == null ? text : "${text}_${meaning}"; |
| } |