Add Element data property

BUG=None
TEST=None

Review URL: https://chromereviews.googleplex.com/3512017

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@71 260f80e4-7a28-3924-810f-c04153c831b5

client/html/html.dart

@@ -549,6 +549,7 @@
 #source('src/BodyElement.dart');
 #source('src/BodyElementWrappingImplementation.dart');
 #source('src/CssClassSet.dart');
+#source('src/DataMap.dart');
 #source('src/DocumentFragment.dart');
 #source('src/DocumentFragmentWrappingImplementation.dart');
 #source('src/DocumentWrappingImplementation.dart');

client/html/src/DataMap.dart

@@ -0,0 +1,82 @@
+// Copyright (c) 2011, 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.
+
+/**
+ * Provides a Map abstraction on top of data-* attributes, similar to the
+ * dataSet in the old DOM.
+ */
+class _DataMap implements Map<String, String> {
+
+  final Map<String, String> _attributes;
+
+  _DataMap(this._attributes);
+
+  // interface Map
+
+  // TODO: Use lazy iterator when it is available on Map.
+  bool containsValue(String value) => getValues().indexOf(value) != -1;
+
+  bool containsKey(String key) => _attributes.containsKey(_attr(key));
+
+  String operator [](String key) => _attributes[_attr(key)];
+
+  void operator []=(String key, String value) {
+    _attributes[_attr(key)] = value;
+  }
+
+  String putIfAbsent(String key, String ifAbsent()) {
+    if (!containsKey(key)) {
+      return this[key] = ifAbsent();
+    }
+    return this[key];
+  }
+
+  String remove(String key) => _attributes.remove(_attr(key));
+
+  void clear() {
+    // Needs to operate on a snapshot since we are mutatiting the collection.
+    for (String key in getKeys()) {
+      remove(key);
+    }
+  }
+
+  void forEach(void f(String key, String value)) {
+    _attributes.forEach((String key, String value) {
+      if (_matches(key)) {
+        f(_strip(key), value);
+      }
+    });
+  }
+
+  Collection<String> getKeys() {
+    final keys = new List<String>();
+    _attributes.forEach((String key, String value) {
+      if (_matches(key)) {
+        keys.add(_strip(key));
+      }
+    });
+    return keys;
+  }
+
+  Collection<String> getValues() {
+    final values = new List<String>();
+    _attributes.forEach((String key, String value) {
+      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;
+
+  // Helpers.
+  String _attr(String key) => 'data-$key';
+  bool _matches(String key) => key.startsWith('data-');
+  String _strip(String key) => key.substringToEnd(5);
+}
+

client/html/src/Element.dart

@@ -84,6 +84,9 @@ interface Element extends Node /*, common.NodeSelector, common.ElementTraversal
   // TODO: The type of value should be Collection<String>. See http://b/5392897
   void set classes(value);
 
+  Map<String, String> get data();
+  void set data(Map<String, String> value);
+
   int get clientHeight();
 
   int get clientLeft();

client/html/src/ElementWrappingImplementation.dart

@@ -283,8 +283,8 @@ class ElementAttributeMap implements Map<String, String> {
 
   void clear() {
     final attributes = _element.attributes;
-    for (int i = 0, len = attributes.length; i < len; i++) {
-      _element.removeAttribute(attributes[0].name);
+    for (int i = len = attributes.length - 1; i >= 0; i--) {
+      _element.removeAttribute(attributes.item(i).name);
     }
   }
 
@@ -402,6 +402,7 @@ class ElementWrappingImplementation extends NodeWrappingImplementation implement
   ElementWrappingImplementation._wrap(ptr) : super._wrap(ptr);
 
   _CssClassSet _cssClassSet;
+  _DataMap _data;
 
   Map<String, String> get attributes() {
     return new ElementAttributeMap._wrap(_ptr);
@@ -422,6 +423,21 @@ class ElementWrappingImplementation extends NodeWrappingImplementation implement
     classSet.addAll(value);
   }
 
+  Map<String, String> get data() {
+    if (_data === null) {
+      _data = new _DataMap(attributes);
+    }
+    return _data;
+  }
+
+  void set data(Map<String, String> value) {
+    Map<String, String> data = this.data;
+    data.clear();
+    for (String key in value.getKeys()) {
+      data[key] = value[key];
+    }
+  }
+
   int get clientHeight() => _ptr.clientHeight;
 
   int get clientLeft() => _ptr.clientLeft;