Add browser-compatible version.

lib/src/resource_impl.dart

+// Copyright (c) 2015, 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.
+
+import "dart:async" show Future, Stream;
+import "dart:convert" show Encoding;
+import "loader.dart";
+import "resolve.dart";
+import "../resource.dart" as core;
+
+/// Default implementation of a generic `Resource` class.
+///
+/// Doesn't actually implement any [Resource] class because different platforms
+/// currently have different top-level classes, so this class can be considered
+/// a mixin or base-class below the actual implementation class.
+/// When configuarble imports make it possible, drop the intermediate classes

[floitsch, 2016/01/21 12:53:57]

This shouldn't be a dartdoc.

[Lasse Reichstein Nielsen, 2016/01/25 10:48:37]

Done.

+/// and make this the default implementation of the top-level `Resource`
+/// interface.
+///
+/// Requires a loader to be provided.
+class Resource {
+  /// Loading strategy for the resource.
+  final ResourceLoader _loader;
+
+  /// The URI of the resource.
+  final _uri;
+
+  const Resource(uri, ResourceLoader loader)
+      : _uri = uri, _loader = loader;
+
+  Uri get uri => (_uri is String) ? Uri.parse(_uri) : (_uri as Uri);
+
+  Stream<List<int>> openRead() async* {
+    Uri uri = await _resolvedUri;
+    yield* _loader.openRead(uri);
+  }
+
+  Future<List<int>> readAsBytes() async {
+    Uri uri = await _resolvedUri;
+    return _loader.readAsBytes(uri);
+  }
+
+  Future<String> readAsString({Encoding encoding}) async {
+    Uri uri = await _resolvedUri;
+    return _loader.readAsString(uri, encoding: encoding);
+  }
+
+  Future<Uri> get _resolvedUri => resolveUri(uri);
+}