| // Copyright (c) 2016, 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 "../resource_loader.dart" as base; |
| import "../package_loader.dart"as base; |
| import "io.dart" as io; |
| |
| /// Resource loading strategy. |
| /// |
| /// An abstraction of the functionality needed to load resources. |
| /// |
| /// Implementations of this interface decide which URI schemes they support. |
| abstract class ResourceLoader implements base.ResourceLoader { |
| /// A resource loader that can load as many of the following URI |
| /// schemes as are supported by the platform: |
| /// * file |
| /// * http |
| /// * https |
| /// * data |
| /// * package |
| /// |
| /// (For example, file: URIs are not supported in the browser). |
| /// Relative URI references are accepted - they are resolved against |
| /// [Uri.base] before being loaded. |
| static ResourceLoader get defaultLoader => |
| const PackageLoader(const DefaultLoader()); |
| } |
| |
| /// Default implementation of [ResourceLoader].. |
| /// |
| /// Uses the system's available loading functionality to implement the |
| /// loading functions. |
| /// |
| /// Supports as many of `http:`, `https:`, `file:` and `data:` URIs as |
| /// possible. |
| class DefaultLoader implements ResourceLoader { |
| const DefaultLoader(); |
| |
| Stream<List<int>> openRead(Uri uri) => io.readAsStream(uri); |
| |
| Future<List<int>> readAsBytes(Uri uri) => io.readAsBytes(uri); |
| |
| Future<String> readAsString(Uri uri, {Encoding encoding}) => |
| io.readAsString(uri, encoding); |
| } |
| |
| // A loader that implements base.PackageLoader *and* ResourceLoader from this |
| // file. |
| class PackageLoader extends base.PackageLoader implements ResourceLoader { |
| const PackageLoader(ResourceLoader loader) : super(loader); |
| } |