First cut at behaviors. This just implements the lifecycle methodsportion. We may get the rest for …

lib/src/common/behavior.dart

+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file

[Siggi Cherem (dart-lang), 2015/08/13 18:52:41]

2015 :)

[jakemac, 2015/08/13 19:14:29]

Acknowledged.

+// 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 polymer.src.common.behavior;
+
+import 'dart:js';
+import 'package:reflectable/reflectable.dart';
+import 'js_proxy.dart';
+
+// Interface for behavior annotations.
+abstract class BehaviorAnnotation {
+  // Returns the JsObject created for this behavior.
+  JsObject getBehavior(Type type);
+}
+
+Map<Type, JsObject> _behaviorsByType = {};
+
+const String _lifecycleMethodsPattern =
+    r'^created|attached|detached|attributeChanged$';
+final RegExp _lifecycleMethodsRegex = new RegExp(_lifecycleMethodsPattern);
+
+// Annotation class for behaviors written in dart.
+class Behavior extends Reflectable implements BehaviorAnnotation {
+  JsObject getBehavior(Type type) {
+    return _behaviorsByType.putIfAbsent(type, () {
+      var obj = new JsObject(context['Object']);
+
+      // Add an entry for each static lifecycle method. These methods must take
+      // a `this` arg as the first argument.
+      var typeMirror = this.reflectType(type);
+      typeMirror.staticMembers.forEach((String name, MethodMirror method) {
+        if (!_lifecycleMethodsRegex.hasMatch(name)) return;
+        if (name == 'attributeChanged') {
+          obj[name] = new JsFunction.withThis(
+              (thisArg, String attributeName, Type type, value) {
+            typeMirror.invoke(
+                name, [dartValue(thisArg), attributeName, type, value]);
+          });
+        } else {
+          obj[name] = new JsFunction.withThis((thisArg) {
+            typeMirror.invoke(name, [thisArg]);
+          });
+        }
+      });
+
+      return obj;
+    });
+  }
+
+  const Behavior()
+      : super(declarationsCapability, typeCapability,
+            const StaticInvokeCapability(_lifecycleMethodsPattern));
+}
+
+const behavior = const Behavior();
+
+// Annotation class for wrappers around behaviors written in javascript.
+class BehaviorProxy implements BehaviorAnnotation {
+  // Path within js global context object to the original js behavior object.
+  final List<String> _jsPath;
+
+  // Returns the actual behavior.
+  JsObject getBehavior(Type type) {
+    return _behaviorsByType.putIfAbsent(type, () {
+      if (_jsPath.isEmpty) {
+        throw 'Invalid empty path for BehaviorProxy $_jsPath.';
+      }
+      var obj = context;
+      for (var part in _jsPath) {
+        obj = obj[part];
+      }
+      return obj;
+    });
+  }
+
+  // TODO(jakemac): Support dot separated Strings for paths?
+  const BehaviorProxy(this._jsPath);
+}