Updating Polymer to derive from custom elements.

pkg/polymer/lib/src/loader.dart

Index: pkg/polymer/lib/src/loader.dart
diff --git a/pkg/polymer/lib/src/loader.dart b/pkg/polymer/lib/src/loader.dart
index e8cbb907da5a65396e5d5d39c25ea641deb03acb..b4301f41b5dd6c99b3cd8cf49d7b8da558f181c6 100644
--- a/pkg/polymer/lib/src/loader.dart
+++ b/pkg/polymer/lib/src/loader.dart
@@ -7,7 +7,8 @@ part of polymer;
 /** Annotation used to automatically register polymer elements. */
 class CustomTag {
   final String tagName;
-  const CustomTag(this.tagName);
+  final Type type;
+  const CustomTag(this.tagName, {Type type}) : this.type = type;

[Siggi Cherem (dart-lang), 2013/10/10 22:25:51]

how about:

const CustomTag(this.tagName, {this.type});

?

[blois, 2013/10/11 22:40:12]

Done.

 }
 
 /**
@@ -36,7 +37,7 @@ void initPolymer(List<String> libraries, [String srcUrl]) {
 
     // TODO(jmesserly): mdv should use initMdv instead of mdv.initialize.
     mdv.initialize();
-    registerCustomElement('polymer-element', () => new PolymerDeclaration());
+    document.register(PolymerDeclaration._TAG, PolymerDeclaration);
 
     for (var lib in libraries) {
       _loadLibrary(lib, srcUrl);
@@ -90,7 +91,7 @@ void _loadLibrary(String uriString, [String srcUrl]) {
     for (var m in c.metadata) {
       var meta = m.reflectee;
       if (meta is CustomTag) {
-        Polymer._registerClassMirror(meta.tagName, c);
+        Polymer.register(meta.tagName, meta.type);

[Jennifer Messerly, 2013/10/10 22:35:17]

it's a bummer that we're going to have a breaking change that Type is required
and then undo it after a few weeks...

Here's a workaround--actually works as far as I can tell :)

We should probably send a patch because the fix seems straightforward in
dart2js. It appears to be a 1-liner: `Type get reflectedType =>
createRuntimeType(_mangledName);` inside JsClassMirror.



// Horrible hack to work around: http://dartbug.com/12607
Type getReflectedTypeWorkaround(ClassMirror cls) {
  // On Dart VM, just return reflectedType.
  if (1.0 is! int) return cls.reflectedType;

  var mangledName = reflect(cls).getField(_mangledNameField).reflectee;
  Type type = _jsHelper.invoke(#createRuntimeType, [mangledName]).reflectee;
  return type;
}

final LibraryMirror _jsHelper =
    currentMirrorSystem().libraries[Uri.parse('dart:_js_helper')];

final Symbol _mangledNameField = () {
  var jsClassMirrorMirror = reflect(reflectClass(ClassMirror)).type;
  for (var name in jsClassMirrorMirror.variables.keys) {
    if (MirrorSystem.getName(name) == '_mangledName') return name;
  }
}();

[blois, 2013/10/11 22:40:12]

Evil. Done.

[Siggi Cherem (dart-lang), 2013/10/14 17:02:52]

Now that you have the workaround, can't we get rid of the 'type' field in
@CustomType?

       }
     }