Add an HTTP library that wraps dart:io.

pkg/http/lib/src/base_request.dart

+// 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 base_request;
+
+import 'dart:io';
+import 'dart:uri';
+
+import 'client.dart';
+import 'streamed_response.dart';
+
+/// The base class for HTTP requests.
+///
+/// Subclasses of [BaseRequest] can be constructed manually and passed to
+/// [BaseClient.send], which allows the user to provide fine-grained control
+/// over the request properties. However, usually it's easier to use convenience
+/// methods like [get] or [BaseClient.get].
+abstract class BaseRequest {
+  /// The HTTP method of the request. Most commonly "GET" or "POST", less
+  /// commonly "HEAD", "PUT", or "DELETE". Non-standard method names are also
+  /// supported.
+  final String method;
+
+  /// The URL to which the request will be sent.
+  final Uri url;
+
+  /// The size of the request body, in bytes. This defaults to -1, which
+  /// indicates that the size of the request is not known in advance.
+  int get contentLength => _contentLength;
+  int _contentLength = -1;
+
+  set contentLength(int value) {
+    _checkFinalized();
+    _contentLength = value;
+  }
+
+  /// Whether a persistent connection should be maintained with the server.
+  /// Defaults to true.
+  bool get persistentConnection => _persistentConnection;
+  bool _persistentConnection = true;
+
+  set persistentConnection(bool value) {
+    _checkFinalized();
+    _persistentConnection = value;
+  }
+
+  /// Whether the client should follow redirects while resolving this request.
+  /// Defaults to true.
+  bool get followRedirects => _followRedirects;
+  bool _followRedirects = true;
+
+  set followRedirects(bool value) {
+    _checkFinalized();
+    _followRedirects = value;
+  }
+
+  /// The maximum number of redirects to follow when [followRedirects] is true.
+  /// If this number is exceeded the [BaseResponse] future will signal a
+  /// [RedirectLimitExceeded] exception. Defaults to 5.
+  int get maxRedirects => _maxRedirects;
+  int _maxRedirects = 5;
+
+  set maxRedirects(int value) {
+    _checkFinalized();
+    _maxRedirects = value;
+  }
+
+  // TODO(nweiz): automatically parse cookies from headers
+
+  // TODO(nweiz): make this a HttpHeaders object
+  /// The headers for this request.
+  final Map<String, String> headers;
+
+  /// Whether the request has been finalized.
+  bool get finalized => _finalized;
+  bool _finalized = false;
+
+  /// Creates a new HTTP request.
+  BaseRequest(this.method, this.url)
+    : headers = <String>{};
+
+  /// Finalizes the HTTP request in preparation for it being sent. This freezes
+  /// all mutable fields and returns an [InputStream] that should emit the body
+  /// of the request. The stream may be closed to indicate a request with no
+  /// body.
+  ///
+  /// The base implementation of this returns null rather than an [InputStream];
+  /// subclasses are responsible for creating the return value. They should also
+  /// freeze any additional mutable fields they add that don't make sense to
+  /// change after the request headers are sent.
+  InputStream finalize() {
+    // TODO(nweiz): freeze headers
+    if (finalized) throw new StateError("Can't finalize a finalized Request.");
+    _finalized = true;
+    return null;
+  }
+
+  /// Sends this request.
+  ///
+  /// This automatically initializes a new [Client] and closes that client once
+  /// the request is complete. If you're planning on making multiple requests to
+  /// the same server, you should use a single [Client] for all of those
+  /// requests.
+  Future<StreamedResponse> send() {
+    var client = new Client();
+    var future = client.send(this);
+    future.onComplete((_) => client.close());
+    return future;
+  }
+
+  /// Throws an error if this request has been finalized.
+  void _checkFinalized() {
+    if (!finalized) return;
+    throw new StateError("Can't modify a finalized Request.");
+  }
+}