refactor(transformers): extract lifecycle hooks from the interfaces

Author: Tim Blasi

modules_dart/analyzer_plugin/lib/src/tasks.dart

@@ -34,7 +34,7 @@ class BuildUnitDirectivesTask extends SourceBasedAnalysisTask {
     List<RenderDirectiveMetadata> metaList = <RenderDirectiveMetadata>[];
     for (CompilationUnitMember unitMember in unit.declarations) {
       if (unitMember is ClassDeclaration) {
-        RenderDirectiveMetadata meta = readDirectiveMetadata(unitMember.metadata);
+        RenderDirectiveMetadata meta = readDirectiveMetadata(unitMember);
         if (meta != null) {
           metaList.add(meta);
         }

modules_dart/transform/lib/src/transform/common/directive_metadata_reader.dart

@@ -6,14 +6,20 @@ import 'package:angular2/src/core/render/api.dart';
 import 'package:angular2/src/core/change_detection/change_detection.dart';
 
 /// Reads [RenderDirectiveMetadata] from the `node`. `node` is expected to be an
-/// instance of [Annotation], [NodeList<Annotation>], ListLiteral, or
-/// [InstanceCreationExpression].
-RenderDirectiveMetadata readDirectiveMetadata(dynamic node) {
-  assert(node is Annotation ||
-      node is NodeList ||
-      node is InstanceCreationExpression ||
-      node is ListLiteral);
-  var visitor = new _DirectiveMetadataVisitor();
+/// instance of [ClassDeclaration] (a class which may have a [Directive] or
+/// [Component] annotation) or an [InstanceCreationExpression] (an instantiation
+/// of [ReflectionInfo]).
+RenderDirectiveMetadata readDirectiveMetadata(AstNode node) {
+  var visitor;
+  if (node is ClassDeclaration) {
+    visitor = new _DeclarationVisitor();
+  } else if (node is InstanceCreationExpression) {
+    visitor = new _ReflectionInfoVisitor();
+  } else {
+    throw new ArgumentError('Incorrect value passed to readDirectiveMetadata. '
+        'Expected types are ClassDeclaration and InstanceCreationExpression '
+        'Provided type was ${node.runtimeType}');
+  }
   node.accept(visitor);
   return visitor.meta;
 }
@@ -45,8 +51,79 @@ num _getDirectiveType(String annotationName, Element element) {
   return byNameMatch;
 }
 
-/// Visitor responsible for processing the `annotations` property of a
-/// [RegisterType] object and pulling out [RenderDirectiveMetadata].
+class _ReflectionInfoVisitor extends _DirectiveMetadataVisitor {
+  // TODO(kegluneq): Create a more robust check that this is a real
+  // `ReflectionInfo` instantiation.
+  static bool _isReflectionInfo(InstanceCreationExpression node) {
+    var name = node.constructorName.type.name;
+    name = name is PrefixedIdentifier ? name.identifier : name;
+    return '$name' == 'ReflectionInfo';
+  }
+
+  @override
+  Object visitInstanceCreationExpression(InstanceCreationExpression node) {
+    if (_isReflectionInfo(node)) {
+      // NOTE(kegluneq): This is very tightly coupled with the `Reflector`
+      // implementation. Clean this up with a better intermediate representation
+      // for .ng_deps.dart files.
+      var reflectionInfoArgs = node.argumentList.arguments;
+      if (reflectionInfoArgs.length > 0) {
+        // Process annotations to determine information specified via
+        // `Component` and `Directive` parameters.
+        reflectionInfoArgs[0].accept(this);
+        if (_hasMeta && reflectionInfoArgs.length > 3) {
+          // Process interfaces to determine which lifecycle events we need to
+          // react to for this `Directive`.
+          _processInterfaces(reflectionInfoArgs[3]);
+        }
+      }
+      return null;
+    }
+    var directiveType = _getDirectiveType(
+        '${node.constructorName.type.name}', node.staticElement);
+    if (directiveType >= 0) {
+      if (_hasMeta) {
+        throw new FormatException(
+            'Only one Directive is allowed per class. '
+            'Found "$node" but already processed "$meta".',
+            '$node' /* source */);
+      }
+      _initializeMetadata(directiveType);
+      super.visitInstanceCreationExpression(node);
+    }
+    // Annotation we do not recognize - no need to visit.
+    return null;
+  }
+
+  void _processInterfaces(Expression lifecycleValue) {
+    _checkMeta();
+    if (lifecycleValue is! ListLiteral) {
+      throw new FormatException(
+          'Angular 2 expects a List but could not understand the value for interfaces. '
+          '$lifecycleValue');
+    }
+    ListLiteral l = lifecycleValue;
+    _populateLifecycle(l.elements.map((s) => s.toSource().split('.').last));
+  }
+}
+
+class _DeclarationVisitor extends _DirectiveMetadataVisitor {
+  @override
+  Object visitClassDeclaration(ClassDeclaration node) {
+    node.metadata.accept(this);
+    if (this._hasMeta) {
+      if (node.implementsClause != null &&
+          node.implementsClause.interfaces != null) {
+        _populateLifecycle(node.implementsClause.interfaces
+            .map((s) => s.toSource().split('.').last));
+      }
+    }
+    return null;
+  }
+}
+
+/// Visitor responsible for processing [Directive] code into a
+/// [RenderDirectiveMetadata] object.
 class _DirectiveMetadataVisitor extends Object
     with RecursiveAstVisitor<Object> {
   bool get _hasMeta => _type != null;
@@ -130,24 +207,6 @@ class _DirectiveMetadataVisitor extends Object
     return null;
   }
 
-  @override
-  Object visitInstanceCreationExpression(InstanceCreationExpression node) {
-    var directiveType = _getDirectiveType(
-        '${node.constructorName.type.name}', node.staticElement);
-    if (directiveType >= 0) {
-      if (_hasMeta) {
-        throw new FormatException(
-            'Only one Directive is allowed per class. '
-            'Found "$node" but already processed "$meta".',
-            '$node' /* source */);
-      }
-      _initializeMetadata(directiveType);
-      super.visitInstanceCreationExpression(node);
-    }
-    // Annotation we do not recognize - no need to visit.
-    return null;
-  }
-
   @override
   Object visitNamedExpression(NamedExpression node) {
     // TODO(kegluneq): Remove this limitation.
@@ -170,10 +229,6 @@ class _DirectiveMetadataVisitor extends Object
       case 'host':
         _populateHost(node.expression);
         break;
-      // TODO(vicb) should come from the interfaces on the class
-      case 'lifecycle':
-        _populateLifecycle(node.expression);
-        break;
       case 'exportAs':
         _populateExportAs(node.expression);
         break;
@@ -207,8 +262,7 @@ class _DirectiveMetadataVisitor extends Object
     if (!_hasMeta) {
       throw new ArgumentError(
           'Incorrect value passed to readDirectiveMetadata. '
-          'Expected types are Annotation, InstanceCreationExpression, '
-          'NodeList or ListLiteral');
+          'Expected types are ClassDeclaration and InstanceCreationExpression');
     }
   }
 
@@ -271,23 +325,19 @@ class _DirectiveMetadataVisitor extends Object
     _exportAs = _expressionToString(exportAsValue, 'Directive#exportAs');
   }
 
-  void _populateLifecycle(Expression lifecycleValue) {
+  void _populateLifecycle(Iterable<String> lifecycleInterfaceNames) {
     _checkMeta();
-    if (lifecycleValue is! ListLiteral) {
-      throw new FormatException(
-          'Angular 2 expects a List but could not understand the value for lifecycle. '
-          '$lifecycleValue');
-    }
-    ListLiteral l = lifecycleValue;
-    var lifecycleEvents = l.elements.map((s) => s.toSource().split('.').last);
-    _callOnDestroy = lifecycleEvents.contains("OnDestroy");
-    _callOnChange = lifecycleEvents.contains("OnChanges");
-    _callDoCheck = lifecycleEvents.contains("DoCheck");
-    _callOnInit = lifecycleEvents.contains("OnInit");
-    _callAfterContentInit = lifecycleEvents.contains("AfterContentInit");
-    _callAfterContentChecked = lifecycleEvents.contains("AfterContentChecked");
-    _callAfterViewInit = lifecycleEvents.contains("AfterViewInit");
-    _callAfterViewChecked = lifecycleEvents.contains("AfterViewChecked");
+    _callOnDestroy = lifecycleInterfaceNames.contains("OnDestroy");
+    _callOnChange = lifecycleInterfaceNames.contains("OnChanges");
+    _callDoCheck = lifecycleInterfaceNames.contains("DoCheck");
+    _callOnInit = lifecycleInterfaceNames.contains("OnInit");
+    _callAfterContentInit =
+        lifecycleInterfaceNames.contains("AfterContentInit");
+    _callAfterContentChecked =
+        lifecycleInterfaceNames.contains("AfterContentChecked");
+    _callAfterViewInit = lifecycleInterfaceNames.contains("AfterViewInit");
+    _callAfterViewChecked =
+        lifecycleInterfaceNames.contains("AfterViewChecked");
   }
 
   void _populateEvents(Expression eventsValue) {
@@ -301,5 +351,6 @@ class _DirectiveMetadataVisitor extends Object
   }
 }
 
-final Map<String, ChangeDetectionStrategy> changeDetectionStrategies
-  = new Map.fromIterable(ChangeDetectionStrategy.values, key: (v) => v.toString());
+final Map<String, ChangeDetectionStrategy> changeDetectionStrategies =
+    new Map.fromIterable(ChangeDetectionStrategy.values,
+        key: (v) => v.toString());

modules_dart/transform/lib/src/transform/common/registered_type.dart

@@ -14,6 +14,9 @@ class RegisteredType {
   /// The actual call to `Reflector#registerType`.
   final MethodInvocation registerMethod;
 
+  /// The `ReflectionInfo` [InstanceCreationExpression]
+  final InstanceCreationExpression reflectionInfoCreate;
+
   /// The factory method registered.
   final Expression factoryFn;
 
@@ -25,22 +28,28 @@ class RegisteredType {
 
   RenderDirectiveMetadata _directiveMetadata = null;
 
-  RegisteredType._(this.typeName, this.registerMethod, this.factoryFn,
-      this.parameters, this.annotations);
+  RegisteredType._(
+      this.typeName,
+      this.registerMethod,
+      this.reflectionInfoCreate,
+      this.factoryFn,
+      this.parameters,
+      this.annotations);
 
   /// Creates a {@link RegisteredType} given a {@link MethodInvocation} node representing
   /// a call to `registerType`.
   factory RegisteredType.fromMethodInvocation(MethodInvocation registerMethod) {
     var visitor = new _ParseRegisterTypeVisitor();
     registerMethod.accept(visitor);
-    return new RegisteredType._(visitor.typeName, registerMethod,
+    return new RegisteredType._(visitor.typeName, registerMethod, visitor.info,
         visitor.factoryFn, visitor.parameters, visitor.annotations);
   }
 
   RenderDirectiveMetadata get directiveMetadata {
     if (_directiveMetadata == null) {
       try {
-        _directiveMetadata = readDirectiveMetadata(annotations);
+        /// TODO(kegluneq): Allow passing a lifecycle interface matcher.
+        _directiveMetadata = readDirectiveMetadata(reflectionInfoCreate);
         if (_directiveMetadata != null) {
           _directiveMetadata.id = '$typeName';
         }
@@ -55,6 +64,7 @@ class RegisteredType {
 class _ParseRegisterTypeVisitor extends Object
     with RecursiveAstVisitor<Object> {
   Identifier typeName;
+  InstanceCreationExpression info;
   Expression factoryFn;
   Expression parameters;
   Expression annotations;
@@ -68,9 +78,9 @@ class _ParseRegisterTypeVisitor extends Object
         ? node.argumentList.arguments[0]
         : null;
 
-    // The second argument to a `registerType` call is the RegistrationInfo
+    // The second argument to a `registerType` call is the `ReflectionInfo`
     // object creation.
-    var info = node.argumentList.arguments[1] as InstanceCreationExpression;
+    info = node.argumentList.arguments[1] as InstanceCreationExpression;
     var args = info.argumentList.arguments;
     for (int i = 0; i < args.length; i++) {
       var arg = args[i];

modules_dart/transform/lib/src/transform/directive_processor/rewriter.dart

@@ -8,7 +8,6 @@ import 'package:angular2/src/core/render/xhr.dart' show XHR;
 import 'package:angular2/src/transform/common/annotation_matcher.dart';
 import 'package:angular2/src/transform/common/asset_reader.dart';
 import 'package:angular2/src/transform/common/async_string_writer.dart';
-import 'package:angular2/src/transform/common/interface_matcher.dart';
 import 'package:angular2/src/transform/common/logging.dart';
 import 'package:angular2/src/transform/common/names.dart';
 import 'package:angular2/src/transform/common/xhr_impl.dart';
@@ -54,12 +53,7 @@ Future<String> createNgDeps(AssetReader reader, AssetId assetId,
   var declarationsCode =
       await _getAllDeclarations(reader, assetId, code, directivesVisitor);
   var declarationsVisitor = new _NgDepsDeclarationsVisitor(
-      assetId,
-      writer,
-      new XhrImpl(reader, assetId),
-      annotationMatcher,
-      _interfaceMatcher,
-      ngMeta,
+      assetId, writer, new XhrImpl(reader, assetId), annotationMatcher, ngMeta,
       inlineViews: inlineViews);
   parseCompilationUnit(declarationsCode, name: '${assetId.path} and parts')
       .declarations
@@ -75,8 +69,6 @@ Future<String> createNgDeps(AssetReader reader, AssetId assetId,
   return writer.asyncToString();
 }
 
-InterfaceMatcher _interfaceMatcher = new InterfaceMatcher();
-
 /// Processes `visitor.parts`, reading and appending their contents to the
 /// original `code`.
 /// Order of `part`s is preserved. That is, if in the main library we have
@@ -278,29 +270,20 @@ class _NgDepsDeclarationsVisitor extends Object with SimpleAstVisitor<Object> {
   /// Angular 2, for example `@Component`.
   final AnnotationMatcher _annotationMatcher;
 
-  /// Responsible for testing whether interfaces are recognized by Angular2,
-  /// for example `OnChanges`.
-  final InterfaceMatcher _interfaceMatcher;
-
   /// Used to fetch linked files.
   final XHR _xhr;
 
-  _NgDepsDeclarationsVisitor(
-      AssetId assetId,
-      AsyncStringWriter writer,
-      XHR xhr,
-      AnnotationMatcher annotationMatcher,
-      InterfaceMatcher interfaceMatcher,
-      this.ngMeta,
+  _NgDepsDeclarationsVisitor(AssetId assetId, AsyncStringWriter writer, XHR xhr,
+      AnnotationMatcher annotationMatcher, this.ngMeta,
       {bool inlineViews})
       : writer = writer,
         _copyVisitor = new ToSourceVisitor(writer),
         _factoryVisitor = new FactoryTransformVisitor(writer),
         _paramsVisitor = new ParameterTransformVisitor(writer),
         _metaVisitor = new AnnotationsTransformVisitor(
-            writer, xhr, annotationMatcher, assetId, inlineViews: inlineViews),
+            writer, xhr, annotationMatcher, assetId,
+            inlineViews: inlineViews),
         _annotationMatcher = annotationMatcher,
-        _interfaceMatcher = interfaceMatcher,
         this.assetId = assetId,
         _xhr = xhr;
 
@@ -445,4 +428,5 @@ class _NgDepsDeclarationsVisitor extends Object with SimpleAstVisitor<Object> {
 }
 
 const _REF_PREFIX = '_ngRef';
-const _REFLECTOR_IMPORT = 'package:angular2/src/core/reflection/reflection.dart';
+const _REFLECTOR_IMPORT =
+    'package:angular2/src/core/reflection/reflection.dart';

modules_dart/transform/test/transform/directive_metadata_extractor/directive_metadata_files/changeDetection.ng_deps.dart

@@ -11,8 +11,9 @@ void initReflector(reflector) {
   reflector
     ..registerType(
         HelloCmp,
-        new ReflectionInfo(
-            const [const Component(changeDetection: ChangeDetectionStrategy.CheckOnce)],
-            const [const []],
-            () => new HelloCmp()));
+        new ReflectionInfo(const [
+          const Component(changeDetection: ChangeDetectionStrategy.CheckOnce)
+        ], const [
+          const []
+        ], () => new HelloCmp()));
 }

modules_dart/transform/test/transform/directive_metadata_extractor/directive_metadata_files/events.ng_deps.dart

@@ -12,7 +12,7 @@ void initReflector(reflector) {
     ..registerType(
         HelloCmp,
         new ReflectionInfo(const [
-          const Component(events: ['onFoo', 'onBar'])
+          const Component(events: const ['onFoo', 'onBar'])
         ], const [
           const []
         ], () => new HelloCmp()));