Index: pkg/web_components/lib/created_watcher.dart |
diff --git a/pkg/web_components/lib/created_watcher.dart b/pkg/web_components/lib/created_watcher.dart |
new file mode 100644 |
index 0000000000000000000000000000000000000000..1eeba3d4d641a9792ade2e674679bf1694036647 |
--- /dev/null |
+++ b/pkg/web_components/lib/created_watcher.dart |
@@ -0,0 +1,36 @@ |
+// Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file |
Jennifer Messerly
2014/06/09 17:28:48
2014?
Siggi Cherem (dart-lang)
2014/06/09 19:29:01
Done.
|
+// 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. |
+ |
+/// Provides notifications whenever a Javascript Custom Elements is created. |
+/// This will not work unless `created_watcher.js` is loaded. |
+library web_components.created_watcher; |
+ |
+import 'dart:async' show Stream, StreamController; |
+import 'dart:html' show document, Element; |
+import 'dart:js' show JsObject, JsFunction; |
+ |
+final _doc = new JsObject.fromBrowserObject(document); |
+int _sequenceId = 0; |
+ |
+/// Returns whether [watch] is supported, which requires to have |
+/// `created_watcher.js` already loaded in the page. |
+bool get isSupported => _doc.hasProperty('registerElementCreatedWatcher'); |
+ |
+/// Watches when Javascript custom elements named [tagName] are created and |
+/// provides a reference to the created element in a broadcast stream. |
+Stream<Element> watch(String tagName, {String extendsTag}) { |
Jennifer Messerly
2014/06/09 17:28:48
extendsTag looks unused -- remove?
Siggi Cherem (dart-lang)
2014/06/09 19:29:02
Now that we call the upgrader, we do need it :)
|
+ if (!isSupported) { |
+ throw new UnsupportedError("Couldn't find `registerElementCreatedWatcher`. " |
Jennifer Messerly
2014/06/09 17:28:48
document.registerElementCreatedWatcher
Siggi Cherem (dart-lang)
2014/06/09 19:29:02
Done.
|
+ "Please make sure that `packages/web_components/created_watcher.js` is " |
+ "loaded and available before calling this function."); |
+ } |
+ |
+ var id = _sequenceId++; |
+ var controller = new StreamController<Element>.broadcast(sync: true, |
Jennifer Messerly
2014/06/09 17:28:48
eeek, this gives me a bad feeling. It feels like m
Siggi Cherem (dart-lang)
2014/06/09 19:29:01
Done. Given the changes we made, I plan to rename
Jennifer Messerly
2014/06/09 19:33:52
yeah sounds good to me. another idea is interop.da
|
+ onCancel: () => |
+ _doc.callMethod('unregisterElementCreatedWatcher', [tagName, id])); |
+ _doc.callMethod('registerElementCreatedWatcher', |
+ [tagName, id, controller.add]); |
+ return controller.stream; |
+} |