Update charted to 0.4.8 and roll

packages/usage/lib/src/usage_impl_io.dart

 // Copyright (c) 2014, 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.
 
-library usage_impl_io;
-
 import 'dart:async';
-import 'dart:convert' show JSON;
+import 'dart:convert' show JSON, JsonEncoder;
 import 'dart:io';
 
 import 'package:path/path.dart' as path;
 
 import 'usage_impl.dart';
 
-String _createUserAgent() {
-  // Mozilla/5.0 (iPhone; U; CPU iPhone OS 5_1_1 like Mac OS X; en)
-  // Dart/1.8.0-edge.41170 (macos; macos; macos; null)
-  String os = Platform.operatingSystem;
-  String locale = Platform.environment['LANG'];
-  return "Dart/${_dartVersion()} (${os}; ${os}; ${os}; ${locale})";
+/// An interface to a Google Analytics session, suitable for use in command-line
+/// applications.
+///
+/// `trackingId`, `applicationName`, and `applicationVersion` values should be supplied.
+/// `analyticsUrl` is optional, and lets user's substitute their own analytics URL for
+/// the default.
+///
+/// `documentDirectory` is where the analytics settings are stored. It
+/// defaults to the user home directory. For regular `dart:io` apps this doesn't need to
+/// be supplied. For Flutter applications, you should pass in a value like
+/// `PathProvider.getApplicationDocumentsDirectory()`.
+class AnalyticsIO extends AnalyticsImpl {
+  AnalyticsIO(
+      String trackingId, String applicationName, String applicationVersion,
+      {String analyticsUrl, Directory documentDirectory})
+      : super(
+            trackingId,
+            new IOPersistentProperties(applicationName,
+                documentDirPath: documentDirectory?.path),
+            new IOPostHandler(),
+            applicationName: applicationName,
+            applicationVersion: applicationVersion,
+            analyticsUrl: analyticsUrl) {
+    final String locale = getPlatformLocale();
+    if (locale != null) {
+      setSessionValue('ul', locale);
+    }
+  }
 }
 
-String _userHomeDir() {
+String _createUserAgent() {
+  final String locale = getPlatformLocale() ?? '';
+
+  if (Platform.isAndroid) {
+    return 'Mozilla/5.0 (Android; Mobile; ${locale})';
+  } else if (Platform.isIOS) {
+    return 'Mozilla/5.0 (iPhone; U; CPU iPhone OS like Mac OS X; ${locale})';
+  } else if (Platform.isMacOS) {
+    return 'Mozilla/5.0 (Macintosh; Intel Mac OS X; Macintosh; ${locale})';
+  } else if (Platform.isWindows) {
+    return 'Mozilla/5.0 (Windows; Windows; Windows; ${locale})';
+  } else if (Platform.isLinux) {
+    return 'Mozilla/5.0 (Linux; Linux; Linux; ${locale})';
+  } else {
+    // Dart/1.8.0 (macos; macos; macos; en_US)
+    String os = Platform.operatingSystem;
+    return "Dart/${getDartVersion()} (${os}; ${os}; ${os}; ${locale})";
+  }
+}
+
+String userHomeDir() {
   String envKey = Platform.operatingSystem == 'windows' ? 'APPDATA' : 'HOME';
   String value = Platform.environment[envKey];
   return value == null ? '.' : value;
 }
 
-String _dartVersion() {
+String getDartVersion() {
   String ver = Platform.version;
   int index = ver.indexOf(' ');
   if (index != -1) ver = ver.substring(0, index);
   return ver;
 }
 
 class IOPostHandler extends PostHandler {
   final String _userAgent;
   final HttpClient mockClient;
 
-  IOPostHandler({HttpClient this.mockClient}) : _userAgent = _createUserAgent();
+  HttpClient _client;
 
-  Future sendPost(String url, Map<String, dynamic> parameters) {
-    // Add custom parameters for OS and the Dart version.
-    parameters['cd1'] = Platform.operatingSystem;
-    parameters['cd2'] = 'dart ${_dartVersion()}';
+  IOPostHandler({this.mockClient}) : _userAgent = _createUserAgent();
 
+  @override
+  Future sendPost(String url, Map<String, dynamic> parameters) async {
     String data = postEncode(parameters);
 
-    HttpClient client = mockClient != null ? mockClient : new HttpClient();
-    client.userAgent = _userAgent;
-    return client.postUrl(Uri.parse(url)).then((HttpClientRequest req) {
+    if (_client == null) {
+      _client = mockClient != null ? mockClient : new HttpClient();
+      _client.userAgent = _userAgent;
+    }
+
+    try {
+      HttpClientRequest req = await _client.postUrl(Uri.parse(url));
       req.write(data);
-      return req.close();
-    }).then((HttpClientResponse response) {
+      HttpClientResponse response = await req.close();
       response.drain();
-    }).catchError((e) {
+    } catch (exception) {
       // Catch errors that can happen during a request, but that we can't do
-      // anything about, e.g. a missing internet conenction.
-    });
+      // anything about, e.g. a missing internet connection.
+    }
   }
+
+  @override
+  void close() => _client?.close();
 }
 
+JsonEncoder _jsonEncoder = new JsonEncoder.withIndent('  ');
+
 class IOPersistentProperties extends PersistentProperties {
   File _file;
   Map _map;
 
-  IOPersistentProperties(String name) : super(name) {
+  IOPersistentProperties(String name, {String documentDirPath}) : super(name) {
     String fileName = '.${name.replaceAll(' ', '_')}';
-    _file = new File(path.join(_userHomeDir(), fileName));
-    _file.createSync();
-    String contents = _file.readAsStringSync();
-    if (contents.isEmpty) contents = '{}';
-    _map = JSON.decode(contents);
+    documentDirPath ??= userHomeDir();
+    _file = new File(path.join(documentDirPath, fileName));
+    if (!_file.existsSync()) {
+      _file.createSync();
+    }
+    syncSettings();
   }
 
-  dynamic operator[](String key) => _map[key];
+  IOPersistentProperties.fromFile(File file) : super(path.basename(file.path)) {
+    _file = file;
+    if (!_file.existsSync()) {
+      _file.createSync();
+    }
+    syncSettings();
+  }
 
-  void operator[]=(String key, dynamic value) {
+  @override
+  dynamic operator [](String key) => _map[key];
+
+  @override
+  void operator []=(String key, dynamic value) {
+    if (value == null && !_map.containsKey(key)) return;
+    if (_map[key] == value) return;
+
     if (value == null) {
       _map.remove(key);
     } else {
       _map[key] = value;
     }
 
-    _file.writeAsStringSync(JSON.encode(_map) + '\n');
+    try {
+      _file.writeAsStringSync(_jsonEncoder.convert(_map) + '\n');
+    } catch (_) {}
+  }
+
+  @override
+  void syncSettings() {
+    try {
+      String contents = _file.readAsStringSync();
+      if (contents.isEmpty) contents = '{}';
+      _map = JSON.decode(contents);
+    } catch (_) {
+      _map = {};
+    }
   }
 }
+
+/// Return the string for the platform's locale; return's `null` if the locale
+/// can't be determined.
+String getPlatformLocale() {
+  String locale = Platform.localeName;
+  if (locale == null) return null;
+
+  if (locale != null) {
+    // Convert `en_US.UTF-8` to `en_US`.
+    int index = locale.indexOf('.');
+    if (index != -1) locale = locale.substring(0, index);
+
+    // Convert `en_US` to `en-us`.
+    locale = locale.replaceAll('_', '-').toLowerCase();
+  }
+
+  return locale;
+}