Add utility methods for sending non-form data in pkg/http.

pkg/http/lib/src/base_client.dart

Index: pkg/http/lib/src/base_client.dart
diff --git a/pkg/http/lib/src/base_client.dart b/pkg/http/lib/src/base_client.dart
index 8c252654741f09d110f55a8648700e477d06f7d0..86925c36fed345923a91a6cd2c4803aceb7a5012 100644
--- a/pkg/http/lib/src/base_client.dart
+++ b/pkg/http/lib/src/base_client.dart
@@ -5,6 +5,7 @@
 library base_client;
 
 import 'dart:async';
+import 'dart:convert';
 import 'dart:io';
 import 'dart:typed_data';
 
@@ -33,27 +34,49 @@ abstract class BaseClient implements Client {
   Future<Response> get(url, {Map<String, String> headers}) =>
     _sendUnstreamed("GET", url, headers);
 
-  /// Sends an HTTP POST request with the given headers and fields to the given
-  /// URL, which can be a [Uri] or a [String]. If any fields are specified, the
-  /// content-type is automatically set to
-  /// `"application/x-www-form-urlencoded"`.
+  /// Sends an HTTP POST request with the given headers and body to the given
+  /// URL, which can be a [Uri] or a [String].
+  ///
+  /// [body] sets the body of the request. It can be a [String], a [List<int>]
+  /// or a [Map<String, String>]. If it's a String, it's encoded using
+  /// [encoding] and used as the body of the request. The content-type of the
+  /// request will default to "text/plain".
+  ///
+  /// If [body] is a List, it's used as a list of bytes for the body of the
+  /// request.
+  ///
+  /// If [body] is a Map, it's encoded as form fields using [encoding]. The
+  /// content-type of the request will be set to
+  /// `"application/x-www-form-urlencoded"`; this cannot be overridden.
+  ///
+  /// [encoding] defaults to UTF-8.
   ///
   /// For more fine-grained control over the request, use [send] instead.
-  Future<Response> post(url,
-      {Map<String, String> headers,
-       Map<String, String> fields}) =>
-    _sendUnstreamed("POST", url, headers, fields);
+  Future<Response> post(url, {Map<String, String> headers, body,
+      Encoding encoding}) =>
+    _sendUnstreamed("POST", url, headers, body, encoding);
 
-  /// Sends an HTTP PUT request with the given headers and fields to the given
-  /// URL, which can be a [Uri] or a [String]. If any fields are specified, the
-  /// content-type is automatically set to
-  /// `"application/x-www-form-urlencoded"`.
+  /// Sends an HTTP PUT request with the given headers and body to the given
+  /// URL, which can be a [Uri] or a [String].
+  ///
+  /// [body] sets the body of the request. It can be a [String], a [List<int>]
+  /// or a [Map<String, String>]. If it's a String, it's encoded using
+  /// [encoding] and used as the body of the request. The content-type of the
+  /// request will default to "text/plain".
+  ///
+  /// If [body] is a List, it's used as a list of bytes for the body of the
+  /// request.
+  ///
+  /// If [body] is a Map, it's encoded as form fields using [encoding]. The
+  /// content-type of the request will be set to
+  /// `"application/x-www-form-urlencoded"`; this cannot be overridden.
+  ///
+  /// [encoding] defaults to UTF-8.
   ///
   /// For more fine-grained control over the request, use [send] instead.
-  Future<Response> put(url,
-      {Map<String, String> headers,
-       Map<String, String> fields}) =>
-    _sendUnstreamed("PUT", url, headers, fields);
+  Future<Response> put(url, {Map<String, String> headers, body,
+      Encoding encoding}) =>
+    _sendUnstreamed("PUT", url, headers, body, encoding);
 
   /// Sends an HTTP DELETE request with the given headers to the given URL,
   /// which can be a [Uri] or a [String].
@@ -103,17 +126,25 @@ abstract class BaseClient implements Client {
   Future<StreamedResponse> send(BaseRequest request);
 
   /// Sends a non-streaming [Request] and returns a non-streaming [Response].
-  Future<Response> _sendUnstreamed(
-      String method, url, Map<String, String> headers,
-      [Map<String, String> fields]) {
-    // Wrap everything in a Future block so that synchronous validation errors
-    // are passed asynchronously through the Future chain.
-    return async.then((_) {
+  Future<Response> _sendUnstreamed(String method, url,
+      Map<String, String> headers, [body, Encoding encoding]) {
+    return new Future.sync(() {
       if (url is String) url = Uri.parse(url);
       var request = new Request(method, url);
 
       if (headers != null) request.headers.addAll(headers);
-      if (fields != null && !fields.isEmpty) request.bodyFields = fields;
+      if (encoding != null) request.encoding = encoding;
+      if (body != null) {
+        if (body is String) {
+          request.body = body;
+        } else if (body is List) {
+          request.bodyBytes = body;
+        } else if (body is Map) {
+          request.bodyFields = body;
+        } else {
+          throw new ArgumentError('Invalid request body "$body".');
+        }
+      }
 
       return send(request);
     }).then(Response.fromStream);