Initial commit of Dart transformer to generate constructor stubs, see https://github.com/angular/an…

modules/angular2/src/transform/transformer.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.
+library angular2.transformer;
+
+import 'dart:async';
+import 'package:barback/barback.dart';
+import 'package:code_transformers/resolver.dart';
+
+import 'annotation_processor.dart';
+import 'codegen.dart' as codegen;
+import 'html_transform.dart';
+import 'options.dart';
+import 'resolvers.dart';
+import 'traversal.dart';
+
+export 'options.dart';
+
+/// Removes the mirror-based initialization logic and replaces it with static
+/// logic.
+class AngularTransformer extends Transformer {
+  final Resolvers _resolvers;
+  final TransformerOptions options;
+
+  AngularTransformer(this.options) : _resolvers = createResolvers();
+
+  static const _entryPointParam = 'entry_point';

[jakemac, 2015/02/17 23:46:46]

not sure that these are necessary, they only appear once below

[tjblasi, 2015/02/18 21:18:25]

They're probably going to change in the future -- this helps me keep them
straight.

+  static const _newEntryPointParam = 'new_entry_point';
+  static const _htmlEntryPointParam = 'html_entry_point';
+
+  factory AngularTransformer.asPlugin(BarbackSettings settings) {
+    var entryPoint = settings.configuration[_entryPointParam];
+    var newEntryPoint = settings.configuration[_newEntryPointParam];
+    if (newEntryPoint == null) {
+      newEntryPoint = entryPoint.replaceFirst('.dart', '.bootstrap.dart');
+    }
+    var htmlEntryPoint = settings.configuration[_htmlEntryPointParam];
+    return new AngularTransformer(
+        new TransformerOptions(entryPoint, newEntryPoint, htmlEntryPoint));
+  }
+
+  bool isPrimary(AssetId id) =>
+      options.entryPoint == id.path || options.htmlEntryPoint == id.path;
+
+  Future apply(Transform transform) {
+    if (transform.primaryInput.id.path == options.entryPoint) {
+      return _buildBootstrapFile(transform);
+    } else if (transform.primaryInput.id.path == options.htmlEntryPoint) {
+      return transformHtmlEntryPoint(options, transform);
+    }
+    return null;
+  }
+
+  Future _buildBootstrapFile(Transform transform) {
+    var newEntryPointId =
+        new AssetId(transform.primaryInput.id.package, options.newEntryPoint);
+    return transform.hasInput(newEntryPointId).then((exists) {
+      if (exists) {
+        transform.logger
+            .error('New entry point file $newEntryPointId already exists.');
+      } else {
+        return _resolvers.get(transform).then((resolver) {
+          new _BootstrapFileBuilder(resolver, transform,
+              transform.primaryInput.id, newEntryPointId).run();
+          resolver.release();
+        });
+      }
+    });
+  }
+}
+
+class _BootstrapFileBuilder {
+  final Resolver _resolver;
+  final Transform _transform;
+  final AssetId _entryPoint;
+  final AssetId _newEntryPoint;
+
+  AnnotationMatcher _directiveInfo;
+
+  _BootstrapFileBuilder(Resolver resolver, Transform transform,
+      this._entryPoint, this._newEntryPoint)
+      : _resolver = resolver,
+        _transform = transform,
+        _directiveInfo = new AnnotationMatcher(resolver
+            .getLibrary(new AssetId(
+                'angular2', 'lib/src/core/annotations/annotations.dart'))
+            .getType('Directive'));
+
+  /// Adds the new entry point file to the transform. Should only be ran once.
+  void run() {
+    var entryLib = _resolver.getLibrary(_entryPoint);
+
+    new ImportTraversal(_directiveInfo).traverse(entryLib);
+
+    var context = new codegen.Context(logger: _transform.logger);
+    _directiveInfo.initQueue
+        .forEach((entry) => context.directiveRegistry.register(entry));
+
+    _transform.addOutput(new Asset.fromString(_newEntryPoint, codegen
+        .codegenEntryPoint(context,
+            entryPoint: entryLib, newEntryPoint: _newEntryPoint)));
+  }
+}