"Reverting 22561"

tools/dom/templates/html/impl/impl_Node.darttemplate

Index: tools/dom/templates/html/impl/impl_Node.darttemplate
diff --git a/tools/dom/templates/html/impl/impl_Node.darttemplate b/tools/dom/templates/html/impl/impl_Node.darttemplate
index 935794b877a1ac2d13d4cae6fee22ea772e7a158..4e9474bef91fd457e7dabb32bf2b75e36a7fbe86 100644
--- a/tools/dom/templates/html/impl/impl_Node.darttemplate
+++ b/tools/dom/templates/html/impl/impl_Node.darttemplate
@@ -121,7 +121,7 @@ $endif
     // time.
     Node child = _this.$dom_firstChild;
     while (child != null) {
-      Node nextChild = child.nextNode;
+      Node nextChild = child.nextSibling;
       if (test(child) == removeMatching) {
         _this.$dom_removeChild(child);
       }
@@ -245,49 +245,96 @@ $(ANNOTATIONS)class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
     }
   }
 
-  /**
-   * Print out a String representation of this Node.
-   */
-  String toString() => localName == null ?
-      (nodeValue == null ? super.toString() : nodeValue) : localName;
+  // Note that this may either be the locally set model or a cached value
+  // of the inherited model. This is cached to minimize model change
+  // notifications.
+$if DART2JS
+  @Creates('Null')
+$endif
+  var _model;
+  bool _hasLocalModel;
+  Set<StreamController<Node>> _modelChangedStreams;
 
   /**
-   * Binds the attribute [name] to the [path] of the [model].
-   * Path is a String of accessors such as `foo.bar.baz`.
+   * The data model which is inherited through the tree.
+   *
+   * Setting this will propagate the value to all descendant nodes. If the
+   * model is not set on this node then it will be inherited from ancestor
+   * nodes.
+   *
+   * Currently this does not support propagation through Shadow DOMs.
+   *
+   * [clearModel] must be used to remove the model property from this node
+   * and have the model inherit from ancestor nodes.
    */
   @Experimental
-  void bind(String name, model, String path) {
-    // TODO(jmesserly): should we throw instead?
-    window.console.error('Unhandled binding to Node: '
-        '$this $name $model $path');
+  get model {
+    // If we have a change handler then we've cached the model locally.
+    if (_modelChangedStreams != null && !_modelChangedStreams.isEmpty) {
+      return _model;
+    }
+    // Otherwise start looking up the tree.
+    for (var node = this; node != null; node = node.parentNode) {
+      if (node._hasLocalModel == true) {
+        return node._model;
+      }
+    }
+    return null;
   }
 
-  /** Unbinds the attribute [name]. */
   @Experimental
-  void unbind(String name) {}
+  void set model(value) {
+    var changed = model != value;
+    _model = value;
+    _hasLocalModel = true;
+    _ModelTreeObserver.initialize();
+
+    if (changed) {
+      if (_modelChangedStreams != null && !_modelChangedStreams.isEmpty) {
+        _modelChangedStreams.toList().forEach((stream) => stream.add(this));
+      }
+      // Propagate new model to all descendants.
+      _ModelTreeObserver.propagateModel(this, value, false);
+    }
+  }
 
-  /** Unbinds all bound attributes. */
+  /**
+   * Clears the locally set model and makes this model be inherited from parent
+   * nodes.
+   */
   @Experimental
-  void unbindAll() {}
-
-  TemplateInstance _templateInstance;
-
-  // TODO(arv): Consider storing all "NodeRareData" on a single object?
-  int __instanceTerminatorCount;
-  int get _instanceTerminatorCount {
-    if (__instanceTerminatorCount == null) return 0;
-    return __instanceTerminatorCount;
+  void clearModel() {
+    if (_hasLocalModel == true) {
+      _hasLocalModel = false;
+
+      // Propagate new model to all descendants.
+      if (parentNode != null) {
+        _ModelTreeObserver.propagateModel(this, parentNode.model, false);
+      } else {
+        _ModelTreeObserver.propagateModel(this, null, false);
+      }
+    }
   }
-  set _instanceTerminatorCount(int value) {
-    if (value == 0) value = null;
-    __instanceTerminatorCount = value;
+
+  /**
+   * Get a stream of models, whenever the model changes.
+   */
+  Stream<Node> get onModelChanged {
+    if (_modelChangedStreams == null) {
+      _modelChangedStreams = new Set<StreamController<Node>>();
+    }
+    var controller;
+    controller = new StreamController(
+        onListen: () { _modelChangedStreams.add(controller); },
+        onCancel: () { _modelChangedStreams.remove(controller); });
+    return controller.stream;
   }
 
-  /** Gets the template instance that instantiated this node, if any. */
-  @Experimental
-  TemplateInstance get templateInstance =>
-      _templateInstance != null ? _templateInstance :
-      (parent != null ? parent.templateInstance : null);
+  /**
+   * Print out a String representation of this Node.
+   */
+  String toString() => localName == null ?
+      (nodeValue == null ? super.toString() : nodeValue) : localName;
 
 $!MEMBERS
 }