Introduce new HttpBodyHandler to easily extract full body of HttpRequest and HttpClientResponse.

sdk/lib/io/http_body.dart

+// Copyright (c) 2013, 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.
+
+part of dart.io;
+
+
+/**
+ * [HttpBodyHandler] is a helper class for parsing and collecting HTTP message
+ * data in an easy-to-use [HttpBody] object. The content body is parsed,
+ * depending on the 'Content-Type' header field.
+ *
+ * To use with the [HttpServer] for request messages, [HttpBodyHandler] can be
+ * used as either a [StreamTransformer] or as a per-request handler (see
+ * [processRequest]).
+ *
+ *     HttpServer server = ...
+ *     server.transform(new HttpBodyHandler())
+ *         .listen((HttpRequestBody body) {
+ *           ...
+ *         });
+ *
+ * To use with the [HttpClient] for response messages, [HttpBodyHandler] can be
+ * used as a per-request handler (see [processResponse]).
+ *
+ *     HttpClient client = ...
+ *     client.get(...)
+ *         .then((HttpClientRequest response) => response.close())
+ *         .then(HttpBodyHandler.processResponse)
+ *         .then((HttpClientResponseBody body) {
+ *           ...
+ *         });
+ *
+ * The following mime-types will be handled specially:
+ *   - text/\*
+ *   - application/json
+ *
+ * All other mime-types will be returned as [List<int>].
+ */
+class HttpBodyHandler
+    implements StreamTransformer<HttpRequest, HttpRequestBody> {
+  factory HttpBodyHandler() => new _HttpBodyHandler();
+
+  /**
+   * Process and parse an incoming [HttpRequest]. The returned [HttpRequestBody]
+   * contains a [response] field for accessing the [HttpResponse].
+   */
+  static Future<HttpRequestBody> processRequest(HttpRequest request) {
+    return _HttpBodyHandler.processRequest(request);
+  }
+
+  /**
+   * Process and parse an incoming [HttpClientResponse].
+   */
+  static Future<HttpClientResponseBody> processResponse(
+      HttpClientResponse response) {
+    return _HttpBodyHandler.processResponse(response);
+  }
+}
+
+
+/**
+ * A HTTP content body produced by [HttpBodyHandler] for either [HttpRequest]
+ * or [HttpClientResponse].
+ */
+abstract class HttpBody {
+  /**
+   * The content type e.g. application/json, application/octet-stream,
+   * application/x-www-form-urlencoded, text/plain.
+   */
+  String get mimeType;
+
+  /**
+   * A high-level type value, that reflects how the body was parsed, e.g.
+   * "text", "binary" and "json".
+   */
+  String get type;
+
+  /**
+   * The actual body. The type depends on [type].
+   */
+  dynamic get body;
+}
+
+
+/**
+ * The [HttpBody] of a [HttpClientResponse] will be of type
+ * [HttpClientResponseBody]. It contains the [HttpClientResponse] object
+ * for access to the headers.
+ */
+abstract class HttpClientResponseBody extends HttpBody {
+  /**
+   * Returns the status code.
+   */
+  int get statusCode;
+
+  /**
+   * Returns the reason phrase associated with the status code.
+   */
+  String get reasonPhrase;
+
+  /**
+   * Returns the response headers.
+   */
+  HttpHeaders get headers;
+
+  /**
+   * The [HttpClientResponse] of the HTTP body.
+   */
+  HttpClientResponse get response;
+}
+
+
+/**
+ * The [HttpBody] of a [HttpRequest] will be of type [HttpRequestBody]. It
+ * contains the fields used to read all request header information and
+ * responding to the client.
+ */
+abstract class HttpRequestBody extends HttpBody {
+  /**
+   * Returns the method for the request.
+   */
+  String get method;
+
+  /**
+   * Returns the URI for the request.
+   */
+  Uri get uri;
+
+  /**
+   * Returns the request headers.
+   */
+  HttpHeaders get headers;
+
+  /**
+   * The [HttpResponse] used for responding to the client.
+   */
+  HttpResponse get response;
+}