Migrate to getter for isEmpty.

lib/html/templates/html/impl/impl_Element.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.
 
 // TODO(jacobr): use _Lists.dart to remove some of the duplicated
 // functionality.
 class _ChildrenElementList implements List {
   // Raw Element.
   final _ElementImpl _element;
   final _HTMLCollectionImpl _childElements;
@@ skipping 47 matching lines @@
   }
 
   Collection map(f(Element element)) {
     final out = [];
     for (Element el in this) {
       out.add(f(el));
     }
     return out;
   }
 
-  bool isEmpty() {
+  bool get isEmpty {
     return _element.$dom_firstElementChild == null;
   }
 
   int get length {
     return _childElements.length;
   }
 
   _ElementImpl operator [](int index) {
     return _childElements[index];
   }
@@ skipping 122 matching lines @@
 
   bool some(bool f(Element element)) {
     for(Element element in this) {
       if (f(element)) {
         return true;
       }
     };
     return false;
   }
 
-  bool isEmpty() => _nodeList.isEmpty();
+  bool get isEmpty => _nodeList.isEmpty;
 
   int get length => _nodeList.length;
 
   Element operator [](int index) => _nodeList[index];
 
   void operator []=(int index, Element value) {
     throw new UnsupportedError('');
   }
 
   void set length(int newLength) {
@@ skipping 153 matching lines @@
   /**
    * The number of {key, value} pairs in the map.
    */
   int get length {
     return _element.$dom_attributes.length;
   }
 
   /**
    * Returns true if there is no {key, value} pair in the map.
    */
-  bool isEmpty() {
+  bool get isEmpty {
     return length == 0;
   }
 }
 
 /**
  * Provides a Map abstraction on top of data-* attributes, similar to the
  * dataSet in the old DOM.
  */
 class _DataAttributeMap implements AttributeMap {
 
@@ skipping 50 matching lines @@
       if (_matches(key)) {
         values.add(value);
       }
     });
     return values;
   }
 
   int get length => getKeys().length;
 
   // TODO: Use lazy iterator when it is available on Map.
-  bool isEmpty() => length == 0;
+  bool get isEmpty => length == 0;
 
   // Helpers.
   String _attr(String key) => 'data-$key';
   bool _matches(String key) => key.startsWith('data-');
   String _strip(String key) => key.substring(5);
 }
 
 class _CssClassSet implements CSSClassSet {
 
   final _ElementImpl _element;
@@ skipping 12 matching lines @@
   }
 
   Collection map(f(String element)) => _read().map(f);
 
   Collection<String> filter(bool f(String element)) => _read().filter(f);
 
   bool every(bool f(String element)) => _read().every(f);
 
   bool some(bool f(String element)) => _read().some(f);
 
-  bool isEmpty() => _read().isEmpty();
+  bool get isEmpty => _read().isEmpty;
 
   bool get frozen => false;
 
   int get length =>_read().length;
 
   // interface Collection - END
 
   // interface Set - BEGIN
   bool contains(String value) => _read().contains(value);
 
@@ skipping 63 matching lines @@
 
   /**
    * Read the class names from the Element class property,
    * and put them into a set (duplicates are discarded).
    */
   Set<String> _read() {
     // TODO(mattsh) simplify this once split can take regex.
     Set<String> s = new Set<String>();
     for (String name in _classname().split(' ')) {
       String trimmed = name.trim();
-      if (!trimmed.isEmpty()) {
+      if (!trimmed.isEmpty) {
         s.add(trimmed);
       }
     }
     return s;
   }
 
   /**
    * Read the class names as a space-separated string. This is meant to be
    * overridden by subclasses.
    */
@@ skipping 287 matching lines @@
 $if DART2JS
   // Optimization to improve performance until the dart2js compiler inlines this
   // method.
   static Element createElement_tag(String tag) =>
       JS('Element', 'document.createElement(#)', tag);
 $else
   static Element createElement_tag(String tag) =>
       _document.$dom_createElement(tag);
 $endif
 }