| // Copyright (c) 2014, 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 barback.declaring_transform; |
| |
| import 'asset_id.dart'; |
| import 'base_transform.dart'; |
| import 'transform_node.dart'; |
| |
| /// A transform for [DeclaringTransform]ers that allows them to declare the ids |
| /// of the outputs they'll generate without generating the concrete bodies of |
| /// those outputs. |
| class DeclaringTransform extends BaseTransform { |
| final _outputIds = new Set<AssetId>(); |
| |
| final AssetId primaryId; |
| |
| DeclaringTransform._(TransformNode node) |
| : primaryId = node.primary.id, |
| super(node); |
| |
| /// Stores [id] as the id of an output that will be created by this |
| /// transformation when it's run. |
| /// |
| /// A transformation can declare as many assets as it wants. If |
| /// [DeclaringTransformer.declareOutputs] declareds a given asset id for a |
| /// given input, [Transformer.apply] should emit the corresponding asset as |
| /// well. |
| void declareOutput(AssetId id) { |
| // TODO(nweiz): This should immediately throw if an output with that ID |
| // has already been declared by this transformer. |
| _outputIds.add(id); |
| } |
| } |
| |
| /// The controller for [DeclaringTransform]. |
| class DeclaringTransformController extends BaseTransformController { |
| DeclaringTransform get transform => super.transform; |
| |
| /// The set of ids that the transformer declares it will emit for the given |
| /// primary input. |
| Set<AssetId> get outputIds => transform._outputIds; |
| |
| DeclaringTransformController(TransformNode node) |
| : super(new DeclaringTransform._(node)); |
| } |