"Reverting 22561"

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

 // Copyright (c) 2012, 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.
 
 part of $LIBRARYNAME;
 
 /**
  * Lazy implementation of the child nodes of an element that does not request
  * the actual child nodes of an element until strictly necessary greatly
  * improving performance for the typical cases where it is not required.
@@ skipping 103 matching lines @@
     _this.$dom_removeChild(node);
     return true;
   }
 
   void _filter(bool test(Node node), bool removeMatching) {
     // This implementation of removeWhere/retainWhere is more efficient
     // than the default in ListBase. Child nodes can be removed in constant
     // 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);
       }
       child = nextChild;
     }
   }
 
   void removeWhere(bool test(Node node)) {
     _filter(test, true);
   }
@@ skipping 103 matching lines @@
         // Should use $dom_firstChild, Bug 8886.
         this.insertBefore(newNodes[0], refChild);
       }
     } else {
       for (var node in newNodes) {
         this.insertBefore(node, refChild);
       }
     }
   }
 
+  // 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;
+
+  /**
+   * 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
+  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;
+  }
+
+  @Experimental
+  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);
+    }
+  }
+
+  /**
+   * Clears the locally set model and makes this model be inherited from parent
+   * nodes.
+   */
+  @Experimental
+  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);
+      }
+    }
+  }
+
+  /**
+   * 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;
+  }
+
   /**
    * Print out a String representation of this Node.
    */
   String toString() => localName == null ?
       (nodeValue == null ? super.toString() : nodeValue) : localName;
 
-  /**
-   * Binds the attribute [name] to the [path] of the [model].
-   * Path is a String of accessors such as `foo.bar.baz`.
-   */
-  @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');
-  }
-
-  /** Unbinds the attribute [name]. */
-  @Experimental
-  void unbind(String name) {}
-
-  /** Unbinds all bound attributes. */
-  @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;
-  }
-  set _instanceTerminatorCount(int value) {
-    if (value == 0) value = null;
-    __instanceTerminatorCount = value;
-  }
-
-  /** Gets the template instance that instantiated this node, if any. */
-  @Experimental
-  TemplateInstance get templateInstance =>
-      _templateInstance != null ? _templateInstance :
-      (parent != null ? parent.templateInstance : null);
-
 $!MEMBERS
 }