Add observatory_pub_packages snapshot to third_party

observatory_pub_packages/polymer/auto_binding.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 polymer.auto_binding;
+
+import 'dart:html';
+import 'package:polymer/polymer.dart';
+import 'package:template_binding/template_binding.dart';
+
+/**
+ * The `auto-binding-dart` element extends the template element. It provides a
+ * quick and easy way to do data binding without the need to setup a binding
+ * delegate or use the [templateBind] call. Both data and event handlers can be
+ * bound using the [model].
+ *
+ * The `auto-binding-dart` element acts just like a template that is bound to
+ * a model. It stamps its content in the dom adjacent to itself. When the
+ * content is stamped, the `template-bound` event is fired.
+ *
+ * **NOTE**: It is a good idea to use an id to select these elements. During
+ * code transformation it is likely that other template elements will be
+ * inserted at the top of the body above yours, so something like
+ * querySelector('template') is likely to break when built.
+ * See http://dartbug.com/20911.
+ *
+ * Example:
+ *
+ *     <template id="my-template" is="auto-binding-dart">
+ *       <div>Say something: <input value="{{value}}"></div>
+ *       <div>You said: {{value}}</div>
+ *       <button on-tap="{{buttonTap}}">Tap me!</button>
+ *     </template>
+ *     <script type="application/dart">
+ *       import 'dart:html';
+ *       import 'package:polymer/polymer.dart';
+ *
+ *       main() {
+ *         var template = document.querySelector('#my-template');
+ *         template.model = new MyModel();
+ *       }
+ *
+ *       class MyModel {
+ *         String value = 'something';
+ *         buttonTap() => console.log('tap!');
+ *       }
+ *     </script>
+ *
+ */
+// Dart note: renamed to avoid conflict with JS auto-binding.
+class AutoBindingElement extends TemplateElement with Polymer, Observable
+    implements TemplateBindExtension {
+
+  /// Make template_binding "extension methods" friendly.
+  /// Note that [NodeBindExtension] is already implemented by [Polymer].
+  TemplateBindExtension _self;
+
+  get model => _self.model;
+  set model(value) { _self.model = value; }
+
+  BindingDelegate get bindingDelegate => _self.bindingDelegate;
+  set bindingDelegate(BindingDelegate value) { _self.bindingDelegate = value; }
+
+  void clear() => _self.clear();
+
+  @override
+  PolymerExpressions get syntax => bindingDelegate;
+
+  AutoBindingElement.created() : super.created() {
+    polymerCreated();
+
+    _self = templateBindFallback(this);
+
+    bindingDelegate = makeSyntax();
+
+    // delay stamping until polymer-ready so that auto-binding is not
+    // required to load last.
+    Polymer.onReady.then((_) {
+      attributes['bind'] = '';
+      // we don't bother with an explicit signal here, we could ust a MO
+      // if necessary
+      async((_) {
+        // note: this will marshall *all* the elements in the parentNode
+        // rather than just stamped ones. We'd need to use createInstance
+        // to fix this or something else fancier.
+        marshalNodeReferences(parentNode);
+        // template stamping is asynchronous so stamping isn't complete
+        // by polymer-ready; fire an event so users can use stamped elements
+        fire('template-bound');
+      });
+    });
+  }
+
+  PolymerExpressions makeSyntax() => new _AutoBindingSyntax(this);
+
+  DocumentFragment createInstance([model, BindingDelegate delegate]) =>
+      _self.createInstance(model, delegate);
+
+  @override
+  dispatchMethod(obj, method, args) {
+    // Dart note: make sure we dispatch to the model, not ourselves.
+    if (identical(obj, this)) obj = model;
+    return super.dispatchMethod(obj, method, args);
+  }
+}
+
+// Dart note: this is implemented a little differently to keep it in classic
+// OOP style. Instead of monkeypatching findController, override it.
+class _AutoBindingSyntax extends PolymerExpressions {
+  final AutoBindingElement _node;
+  _AutoBindingSyntax(this._node) : super();
+  @override findController(_) => _node;
+}