Merge branch 'resource-owner-password-grant'

Closes #14
Closes #15
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 686b6ac..f5865d2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -23,6 +23,8 @@
 
 ## Non-breaking changes
 
+* Added a `resourceOwnerPasswordGrant` method.
+
 * The `scopes` argument to `AuthorizationCodeGrant.getAuthorizationUrl()` and
   `new Credentials()` and the `newScopes` argument to `Credentials.refresh` now
   take an `Iterable` rather than just a `List`.
diff --git a/README.md b/README.md
index 7e390cd..ad3b0c0 100644
--- a/README.md
+++ b/README.md
@@ -12,11 +12,15 @@
 
 OAuth2 provides several different methods for the client to obtain
 authorization. At the time of writing, this library only supports the
-[AuthorizationCodeGrant][] method, but further methods may be added in the
-future. The following example uses this method to authenticate, and assumes
-that the library is being used by a server-side application.
+[AuthorizationCodeGrant][] and [resourceOwnerPasswordGrant][] methods, but
+further methods may be added in the future. The following example uses this
+method to authenticate, and assumes that the library is being used by a
+server-side application.
 
-[AuthorizationCodeGrant]: https://api.dartlang.org/apidocs/channels/stable/#oauth2/oauth2.AuthorizationCodeGrant
+[AuthorizationCodeGrant]: http://www.dartdocs.org/documentation/oauth2/latest/index.html#oauth2/oauth2.AuthorizationCodeGrant
+[resourceOwnerPasswordGrant]: http://www.dartdocs.org/documentation/oauth2/latest/index.html#oauth2/oauth2.resourceOwnerPasswordGrant
+
+## Authorization Code Grant
 
 ```dart
 import 'dart:io'
@@ -107,3 +111,41 @@
   print(result);
 }
 ```
+
+## Resource Owner Password Grant
+
+```dart
+// This URL is an endpoint that's provided by the authorization server. It's
+// usually included in the server's documentation of its OAuth2 API.
+final authorizationEndpoint =
+    Uri.parse("http://example.com/oauth2/authorization");
+
+// The user should supply their own username and password.
+final username = "example user";
+final password = "example password";
+
+// The authorization server may issue each client a separate client
+// identifier and secret, which allows the server to tell which client
+// is accessing it. Some servers may also have an anonymous
+// identifier/secret pair that any client may use.
+//
+// Some servers don't require the client to authenticate itself, in which case
+// these should be omitted.
+final identifier = "my client identifier";
+final secret = "my client secret";
+
+// Make a request to the authorization endpoint that will produce the fully
+// authenticated Client.
+var client = await oauth2.resourceOwnerPasswordGrant(
+    authorizationEndpoint, username, password,
+    identifier: identifier, secret: secret);
+
+// Once you have the client, you can use it just like any other HTTP client.
+var result = await client.read("http://example.com/protected-resources.txt");
+
+// Once we're done with the client, save the credentials file. This will allow
+// us to re-use the credentials and avoid storing the username and password
+// directly.
+new File("~/.myapp/credentials.json")
+    .writeAsString(client.credentials.toJson());
+```
diff --git a/lib/oauth2.dart b/lib/oauth2.dart
index cb3c592..01474ed 100644
--- a/lib/oauth2.dart
+++ b/lib/oauth2.dart
@@ -5,6 +5,7 @@
 library oauth2;
 
 export 'src/authorization_code_grant.dart';
+export 'src/resource_owner_password_grant.dart';
 export 'src/client.dart';
 export 'src/credentials.dart';
 export 'src/authorization_exception.dart';
diff --git a/lib/src/client.dart b/lib/src/client.dart
index adf53d5..c27ab4e 100644
--- a/lib/src/client.dart
+++ b/lib/src/client.dart
@@ -12,7 +12,6 @@
 import 'authorization_exception.dart';
 import 'credentials.dart';
 import 'expiration_exception.dart';
-import 'utils.dart';
 
 // TODO(nweiz): Add an onCredentialsRefreshed event once we have some event
 // infrastructure.
@@ -79,7 +78,8 @@
   /// Creates a new client from a pre-existing set of credentials.
   ///
   /// When authorizing a client for the first time, you should use
-  /// [AuthorizationCodeGrant] instead of constructing a [Client] directly.
+  /// [AuthorizationCodeGrant] or [resourceOwnerPasswordGrant] instead of
+  /// constructing a [Client] directly.
   ///
   /// [httpClient] is the underlying client that this forwards requests to after
   /// adding authorization credentials to them.
diff --git a/lib/src/resource_owner_password_grant.dart b/lib/src/resource_owner_password_grant.dart
new file mode 100644
index 0000000..28498ca
--- /dev/null
+++ b/lib/src/resource_owner_password_grant.dart
@@ -0,0 +1,70 @@
+// 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.
+
+library oauth2.resource_owner_password_grant;
+
+import 'dart:async';
+
+import 'package:http/http.dart' as http;
+
+import 'client.dart';
+import 'handle_access_token_response.dart';
+import 'utils.dart';
+
+/// Obtains credentials using a [resource owner password grant][].
+///
+/// This mode of authorization uses the user's username and password to obtain
+/// an authentication token, which can then be stored. This is safer than
+/// storing the username and password directly, but it should be avoided if any
+/// other authorization method is available, since it requires the user to
+/// provide their username and password to a third party (you).
+///
+/// The client [identifier] and [secret] may be issued by the server, and are
+/// used to identify and authenticate your specific OAuth2 client. These are
+/// usually global to the program using this library.
+///
+/// The specific permissions being requested from the authorization server may
+/// be specified via [scopes]. The scope strings are specific to the
+/// authorization server and may be found in its documentation. Note that you
+/// may not be granted access to every scope you request; you may check the
+/// [Credentials.scopes] field of [Client.credentials] to see which scopes you
+/// were granted.
+Future<Client> resourceOwnerPasswordGrant(
+    Uri authorizationEndpoint,
+    String username,
+    String password,
+    {String identifier,
+    String secret,
+    Iterable<String> scopes,
+    bool basicAuth: true,
+    http.Client httpClient}) async {
+  var startTime = new DateTime.now();
+
+  var body = {
+    "grant_type": "password",
+    "username": username,
+    "password": password
+  };
+
+  var headers = {};
+
+  if (identifier != null) {
+    if (basicAuth) {
+      headers['Authorization'] = basicAuthHeader(identifier, secret);
+    } else {
+      body['client_id'] = identifier;
+      if (secret != null) body['client_secret'] = secret;
+    }
+  }
+
+  if (scopes != null && !scopes.isEmpty) body['scope'] = scopes.join(' ');
+
+  if (httpClient == null) httpClient = new http.Client();
+  var response = await httpClient.post(authorizationEndpoint,
+      headers: headers, body: body);
+
+  var credentials = await handleAccessTokenResponse(
+      response, authorizationEndpoint, startTime, scopes);
+  return new Client(credentials, identifier: identifier, secret: secret);
+}
diff --git a/pubspec.yaml b/pubspec.yaml
index f52b8be..bd6bd4c 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: oauth2
-version: 1.0.0-dev
+version: 1.0.0
 author: Dart Team <misc@dartlang.org>
 homepage: http://github.com/dart-lang/oauth2
 description: >
diff --git a/test/resource_owner_password_grant_test.dart b/test/resource_owner_password_grant_test.dart
new file mode 100644
index 0000000..1d73a0f
--- /dev/null
+++ b/test/resource_owner_password_grant_test.dart
@@ -0,0 +1,114 @@
+// 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.
+
+@TestOn("vm")
+
+import 'dart:async';
+import 'dart:convert';
+
+import 'package:crypto/crypto.dart';
+import 'package:http/http.dart' as http;
+import 'package:oauth2/oauth2.dart' as oauth2;
+import 'package:test/test.dart';
+
+import 'utils.dart';
+
+final success = JSON.encode({
+  "access_token": "2YotnFZFEjr1zCsicMWpAA",
+  "token_type": "bearer",
+  "expires_in": 3600,
+  "refresh_token": "tGzv3JOkF0XG5Qx2TlKWIA",
+});
+
+var auth = 'Basic Y2xpZW50OnNlY3JldA==';
+var authEndpoint = Uri.parse('https://example.com');
+
+void main() {
+  var expectClient;
+  setUp(() => expectClient = new ExpectClient());
+
+  group('basic', () {
+    test('builds correct request with client when using basic auth for client',
+        () async {
+      expectClient.expectRequest((request) async {
+        expect(auth, equals(request.headers['authorization']));
+        expect(request.bodyFields['grant_type'], equals('password'));
+        expect(request.bodyFields['username'], equals('username'));
+        expect(request.bodyFields['password'], equals('userpass'));
+        return new http.Response(success, 200,
+            headers: {'content-type': 'application/json'});
+      });
+
+      var client = await oauth2.resourceOwnerPasswordGrant(
+          authEndpoint, 'username', 'userpass',
+          identifier: 'client', secret: 'secret', httpClient: expectClient);
+
+      expect(client.credentials, isNotNull);
+      expect(client.credentials.accessToken, equals('2YotnFZFEjr1zCsicMWpAA'));
+    });
+
+    test('builds correct request when using query parameters for client',
+        () async {
+      expectClient.expectRequest((request) async {
+        expect(request.bodyFields['grant_type'], equals('password'));
+        expect(request.bodyFields['client_id'], equals('client'));
+        expect(request.bodyFields['client_secret'], equals('secret'));
+        expect(request.bodyFields['username'], equals('username'));
+        expect(request.bodyFields['password'], equals('userpass'));
+        return new http.Response(success, 200,
+            headers: {'content-type': 'application/json'});
+      });
+
+      var client = await oauth2.resourceOwnerPasswordGrant(
+          authEndpoint, 'username', 'userpass',
+          identifier: 'client',
+          secret: 'secret',
+          basicAuth: false,
+          httpClient: expectClient);
+      expect(client.credentials, isNotNull);
+      expect(client.credentials.accessToken, equals('2YotnFZFEjr1zCsicMWpAA'));
+    });
+
+    test('builds correct request using scope', () async {
+      expectClient.expectRequest((request) async {
+        expect(request.bodyFields['grant_type'], equals('password'));
+        expect(request.bodyFields['username'], equals('username'));
+        expect(request.bodyFields['password'], equals('userpass'));
+        expect(request.bodyFields['scope'], equals('one two'));
+        return new http.Response(success, 200,
+            headers: {'content-type': 'application/json'});
+      });
+
+      var client = await oauth2.resourceOwnerPasswordGrant(
+          authEndpoint, 'username', 'userpass',
+          scopes: ['one', 'two'], httpClient: expectClient);
+      expect(client.credentials, isNotNull);
+      expect(client.credentials.accessToken, equals('2YotnFZFEjr1zCsicMWpAA'));
+    });
+
+    test('merges with existing query parameters', () async {
+      var authEndpoint = Uri.parse('https://example.com?query=value');
+
+      expectClient.expectRequest((request) async {
+        expect(request.bodyFields['grant_type'], equals('password'));
+        expect(request.bodyFields['client_id'], equals('client'));
+        expect(request.bodyFields['client_secret'], equals('secret'));
+        expect(request.bodyFields['username'], equals('username'));
+        expect(request.bodyFields['password'], equals('userpass'));
+        expect(request.url.queryParameters['query'], equals('value'));
+        return new http.Response(success, 200,
+            headers: {'content-type': 'application/json'});
+      });
+
+      var client = await oauth2.resourceOwnerPasswordGrant(
+          authEndpoint, 'username', 'userpass',
+          identifier: 'client',
+          secret: 'secret',
+          basicAuth: false,
+          httpClient: expectClient);
+      expect(client.credentials, isNotNull);
+      expect(client.credentials.accessToken, equals('2YotnFZFEjr1zCsicMWpAA'));
+    });
+  });
+}