Wrapping leaf nodes in non polymer elements

runtime/observatory/lib/src/elements/error_ref.dart

 // Copyright (c) 2014, 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 error_ref_element;
 
-import 'package:polymer/polymer.dart';
-import 'service_ref.dart';
+import 'dart:html';
+import 'package:observatory/repositories.dart'
+  show ErrorRef;
+import 'package:observatory/src/elements/helpers/tag.dart';
 
-@CustomTag('error-ref')
-class ErrorRefElement extends ServiceRefElement {
+class ErrorRefElement extends HtmlElement {
+  static const tag = const Tag<ErrorRefElement>('error-ref-wrapped');
+
+  ErrorRef _error;
+  ErrorRef get error => _error;
+
+  factory ErrorRefElement(ErrorRef error) {
+    assert(error != null);
+    ErrorRefElement e = document.createElement(tag.name);
+    e._error = error;
+    return e;
+  }
+
   ErrorRefElement.created() : super.created();
+
+  @override
+  void attached() {
+    super.attached();
+    assert(error != null);
+    render();
+  }
+
+  void render() {
+    children = [
+      new PreElement()..text = error.message
+    ];
+  }
 }