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1 // Copyright (c) 2014, the Dart project authors. Please see the AUTHORS file | 1 // Copyright (c) 2014, the Dart project authors. Please see the AUTHORS file |
2 // for details. All rights reserved. Use of this source code is governed by a | 2 // for details. All rights reserved. Use of this source code is governed by a |
3 // BSD-style license that can be found in the LICENSE file. | 3 // BSD-style license that can be found in the LICENSE file. |
4 | 4 |
5 library barback.transformer.declaring_transform; | 5 library barback.transformer.declaring_transform; |
6 | 6 |
7 import 'dart:async'; | 7 import 'dart:async'; |
8 | 8 |
9 import '../asset/asset_id.dart'; | 9 import '../asset/asset_id.dart'; |
10 import 'declaring_aggregate_transform.dart'; | 10 import 'declaring_aggregate_transform.dart'; |
11 import 'transform_logger.dart'; | 11 import 'transform_logger.dart'; |
12 | 12 |
13 /// Creates a new [DeclaringTransform] wrapping an | 13 /// Creates a new [DeclaringTransform] wrapping an |
14 /// [AggregateDeclaringTransform]. | 14 /// [AggregateDeclaringTransform]. |
15 /// | 15 /// |
16 /// Although barback internally works in terms of | 16 /// Although barback internally works in terms of |
17 /// [DeclaringAggregateTransformer]s, most transformers only work on individual | 17 /// [DeclaringAggregateTransformer]s, most transformers only work on individual |
18 /// primary inputs in isolation. We want to allow those transformers to | 18 /// primary inputs in isolation. We want to allow those transformers to |
19 /// implement the more user-friendly [DeclaringTransformer] interface which | 19 /// implement the more user-friendly [DeclaringTransformer] interface which |
20 /// takes the more user-friendly [DeclaringTransform] object. This method wraps | 20 /// takes the more user-friendly [DeclaringTransform] object. This method wraps |
21 /// the more general [DeclaringAggregateTransform] to return a | 21 /// the more general [DeclaringAggregateTransform] to return a |
22 /// [DeclaringTransform] instead. | 22 /// [DeclaringTransform] instead. |
23 Future<DeclaringTransform> newDeclaringTransform( | 23 Future<DeclaringTransform> newDeclaringTransform( |
24 DeclaringAggregateTransform aggregate) { | 24 DeclaringAggregateTransform aggregate) { |
25 // A wrapped [Transformer] will assign each primary input a unique transform | 25 // A wrapped [Transformer] will assign each primary input a unique transform |
26 // key, so we can safely get the first asset emitted. We don't want to wait | 26 // key, so we can safely get the first asset emitted. We don't want to wait |
27 // for the stream to close, since that requires barback to prove that no more | 27 // for the stream to close, since that requires barback to prove that no more |
28 // new assets will be generated. | 28 // new assets will be generated. |
29 return aggregate.primaryIds.first.then((primaryId) => | 29 return aggregate.primaryIds.first |
30 new DeclaringTransform._(aggregate, primaryId)); | 30 .then((primaryId) => new DeclaringTransform._(aggregate, primaryId)); |
31 } | 31 } |
32 | 32 |
33 /// A transform for [DeclaringTransformer]s that allows them to declare the ids | 33 /// A transform for [DeclaringTransformer]s that allows them to declare the ids |
34 /// of the outputs they'll generate without generating the concrete bodies of | 34 /// of the outputs they'll generate without generating the concrete bodies of |
35 /// those outputs. | 35 /// those outputs. |
36 class DeclaringTransform { | 36 class DeclaringTransform { |
37 /// The underlying aggregate transform. | 37 /// The underlying aggregate transform. |
38 final DeclaringAggregateTransform _aggregate; | 38 final DeclaringAggregateTransform _aggregate; |
39 | 39 |
40 final AssetId primaryId; | 40 final AssetId primaryId; |
(...skipping 14 matching lines...) Expand all Loading... |
55 | 55 |
56 /// Consume the primary input so that it doesn't get processed by future | 56 /// Consume the primary input so that it doesn't get processed by future |
57 /// phases or emitted once processing has finished. | 57 /// phases or emitted once processing has finished. |
58 /// | 58 /// |
59 /// Normally the primary input will automatically be forwarded unless the | 59 /// Normally the primary input will automatically be forwarded unless the |
60 /// transformer overwrites it by emitting an input with the same id. This | 60 /// transformer overwrites it by emitting an input with the same id. This |
61 /// allows the transformer to tell barback not to forward the primary input | 61 /// allows the transformer to tell barback not to forward the primary input |
62 /// even if it's not overwritten. | 62 /// even if it's not overwritten. |
63 void consumePrimary() => _aggregate.consumePrimary(primaryId); | 63 void consumePrimary() => _aggregate.consumePrimary(primaryId); |
64 } | 64 } |
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