port Node.bind to bd0a0591920da9091b326627a46a104a92c7efe7

pkg/template_binding/lib/src/input_element.dart

 // 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.
 
 part of template_binding;
 
 /** Extensions to the [InputElement] API. */
 class _InputElementExtension extends _ElementExtension {
   _InputElementExtension(InputElement node) : super(node);
 
   InputElement get _node => super._node;
 
-  NodeBinding createBinding(String name, model, String path) {
-    if (name == 'value') {
-      // TODO(rafaelw): Maybe template should remove all binding instructions.
-      _node.attributes.remove(name);
-      return new _ValueBinding(_node, model, path);
+  NodeBinding bind(String name, model, [String path]) {
+    if (name != 'value' && name != 'checked') {
+      return super.bind(name, model, path);
     }
-    if (name == 'checked') {
-      _node.attributes.remove(name);
-      return new _CheckedBinding(_node, model, path);
-    }
-    return super.createBinding(name, model, path);
+
+    _self.unbind(name);
+    _node.attributes.remove(name);
+    return bindings[name] = name == 'value' ?
+        new _ValueBinding(_node, model, path) :
+        new _CheckedBinding(_node, model, path);
   }
 }