Port of github.com/polymer/polymer.

pkg/polymer/lib/src/loader.dart

-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2013, 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.
 
-/**
- * Custom HTML tags, data binding, and templates for building
- * structured, encapsulated, client-side web apps.
- *
- * Polymer.dart, the next evolution of Web UI,
- * is an in-progress Dart port of the
- * [Polymer project](http://www.polymer-project.org/).
- * Polymer.dart compiles to JavaScript and runs across the modern web.
- *
- * To use polymer.dart in your application,
- * first add a
- * [dependency](http://pub.dartlang.org/doc/dependencies.html)
- * to the app's pubspec.yaml file.
- * Instead of using the open-ended `any` version specifier,
- * we recommend using a range of version numbers, as in this example:
- *
- *     dependencies:
- *       polymer: '>=0.7.1 <0.8'
- *
- * Then import the library into your application:
- *
- *     import 'package:polymer/polymer.dart';
- *
- * ## Other resources
- *
- * * [Polymer.dart homepage](http://www.dartlang.org/polymer-dart/):
- * Example code, project status, and
- * information about how to get started using Polymer.dart in your apps.
- *
- * * [polymer.dart package](http://pub.dartlang.org/packages/polymer):
- * More details, such as the current major release number.
- *
- * * [Upgrading to Polymer.dart](http://www.dartlang.org/polymer-dart/upgrading-to-polymer-from-web-ui.html):
- * Tips for converting your apps from Web UI to Polymer.dart.
- */
-library polymer;
-
-import 'dart:async';
-import 'dart:mirrors';
-
-import 'package:mdv/mdv.dart' as mdv;
-import 'package:observe/src/microtask.dart';
-import 'package:path/path.dart' as path;
-import 'polymer_element.dart' show registerPolymerElement;
-
-export 'package:custom_element/custom_element.dart';
-export 'package:observe/observe.dart';
-export 'package:observe/html.dart';
-export 'package:observe/src/microtask.dart';
-
-export 'polymer_element.dart';
-
+part of polymer;
 
 /** Annotation used to automatically register polymer elements. */
 class CustomTag {
   final String tagName;
   const CustomTag(this.tagName);
 }
 
 /**
  * Metadata used to label static or top-level methods that are called
  * automatically when loading the library of a custom element.
  */
 const initMethod = const _InitMethodAnnotation();
 
 /**
  * Initializes a polymer application as follows:
  *   * set up up polling for observable changes
  *   *  initialize MDV
  *   *  for each library in [libraries], register custom elements labeled with
  *      [CustomTag] and invoke the initialization method on it.
  *
  * The initialization on each library is either a method named `main` or
  * a top-level function and annotated with [initMethod].
  *
  * The urls in [libraries] can be absolute or relative to [srcUrl].
  */
 void initPolymer(List<String> libraries, [String srcUrl]) {
-  wrapMicrotask(() {
+  runMicrotask(() {
     // DOM events don't yet go through microtasks, so we catch those here.
     new Timer.periodic(new Duration(milliseconds: 125),
         (_) => performMicrotaskCheckpoint());
 
     // TODO(jmesserly): mdv should use initMdv instead of mdv.initialize.
     mdv.initialize();
+    registerCustomElement('polymer-element', () => new PolymerDeclaration());
+
     for (var lib in libraries) {
       _loadLibrary(lib, srcUrl);
     }
-  })();
+
+    // TODO(jmesserly): this should be in the custom_element polyfill, not here.
+    // notify the system that we are bootstrapped
+    document.body.dispatchEvent(

[blois, 2013/09/27 21:40:52]

Seems like this should be a separate event- when custom element polyfill arrives
this will want to wait for that then raise a new event?

[Jennifer Messerly, 2013/09/30 17:44:37]

I don't see why we'd need an extra event over polymer.js, unless we messed up
something in the timing. I need it now because I'm still using xtags based
custom_element "polyfill".

+        new CustomEvent('WebComponentsReady', canBubble: true));
+  });
 }
 
 /** All libraries in the current isolate. */
 final _libs = currentMirrorSystem().libraries;
 
 /**
  * Reads the library at [uriString] (which can be an absolute URI or a relative
  * URI from [srcUrl]), and:
  *
  *   * If present, invokes `main`.
@@ skipping 23 matching lines @@
   // Search top-level functions marked with @initMethod
   for (var f in lib.functions.values) {
     _maybeInvoke(lib, f);
   }
 
   for (var c in lib.classes.values) {
     // Search for @CustomTag on classes
     for (var m in c.metadata) {
       var meta = m.reflectee;
       if (meta is CustomTag) {
-        registerPolymerElement(meta.tagName,
-            () => c.newInstance(const Symbol(''), const []).reflectee);
+        Polymer._registerClassMirror(meta.tagName, c);
       }
     }
 
     // TODO(sigmund): check also static methods marked with @initMethod.
     // This is blocked on two bugs:
     //  - dartbug.com/12133 (static methods are incorrectly listed as top-level
     //    in dart2js, so they end up being called twice)
     //  - dartbug.com/12134 (sometimes "method.metadata" throws an exception,
     //    we could wrap and hide those exceptions, but it's not ideal).
   }
@@ skipping 17 matching lines @@
     print("warning: methods marked with @initMethod should take no "
         "arguments, ${method.simpleName} expects some.");
     return;
   }
   obj.invoke(method.simpleName, const []);
 }
 
 class _InitMethodAnnotation {
   const _InitMethodAnnotation();
 }