Expose aggregate transformers in barback.

pkg/barback/lib/src/graph/phase.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.
 
 library barback.graph.phase;
 
 import 'dart:async';
 
 import '../asset/asset_id.dart';
 import '../asset/asset_node.dart';
 import '../asset/asset_node_set.dart';
 import '../errors.dart';
 import '../log.dart';
+import '../transformer/aggregate_transformer.dart';
 import '../transformer/transformer.dart';
 import '../transformer/transformer_group.dart';
 import '../utils.dart';
 import '../utils/multiset.dart';
 import 'asset_cascade.dart';
 import 'group_runner.dart';
 import 'node_status.dart';
 import 'node_streams.dart';
 import 'phase_forwarder.dart';
 import 'phase_output.dart';
@@ skipping 24 matching lines @@
   /// The groups for this phase.
   final _groups = new Map<TransformerGroup, GroupRunner>();
 
   /// The inputs for this phase.
   ///
   /// For the first phase, these will be the source assets. For all other
   /// phases, they will be the outputs from the previous phase.
   final _inputs = new AssetNodeSet();
 
   /// The transformer classifiers for this phase.
-  final _classifiers = new Map<Transformer, TransformerClassifier>();
+  ///
+  /// The keys can be either [Transformer]s or [AggregateTransformer]s.
+  final _classifiers = new Map<dynamic, TransformerClassifier>();
 
   /// The forwarders for this phase.
   final _forwarders = new Map<AssetId, PhaseForwarder>();
 
   /// The outputs for this phase.
   final _outputs = new Map<AssetId, PhaseOutput>();
 
   /// The set of all [AssetNode.origin] properties of the input assets for this
   /// phase.
   ///
@@ skipping 157 matching lines @@
       // Otherwise, store a completer for the asset node. If it's generated in
       // the future, we'll complete this completer.
       var completer = _pendingOutputRequests.putIfAbsent(id,
           () => new Completer.sync());
       return completer.future;
     });
   }
 
   /// Set this phase's transformers to [transformers].
   void updateTransformers(Iterable transformers) {
-    var newTransformers = transformers.where((op) => op is Transformer)
+    var newTransformers = transformers
+        .where((op) => op is Transformer || op is AggregateTransformer)
         .toSet();
     var oldTransformers = _classifiers.keys.toSet();
     for (var removed in oldTransformers.difference(newTransformers)) {
       _classifiers.remove(removed).remove();
     }
 
     for (var transformer in newTransformers.difference(oldTransformers)) {
       var classifier = new TransformerClassifier(
           this, transformer, "$_location.$_index");
       _classifiers[transformer] = classifier;
@@ skipping 131 matching lines @@
     assert(asset.state.isDirty);
     asset.force();
     asset.whenStateChanges().then((state) {
       if (state.isRemoved) return getOutput(asset.id);
       return asset;
     }).then(request.complete).catchError(request.completeError);
   }
 
   String toString() => "phase $_location.$_index";
 }