Adding support for accessing attributes in alternate namespaces.

sdk/lib/html/src/AttributeMap.dart

+// 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 html;
+
+abstract class _AttributeMap implements Map<String, String> {
+
+  bool containsValue(String value) {
+    for (var v in this.values) {
+      if (value == v) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  String putIfAbsent(String key, String ifAbsent()) {
+    if (!containsKey(key)) {
+      this[key] = ifAbsent();
+    }
+    return this[key];
+  }
+
+  void clear() {
+    for (var key in keys) {
+      remove(key);
+    }
+  }
+
+  void forEach(void f(String key, String value)) {
+    for (var key in keys) {
+      var value = this[key];
+      f(key, value);
+    }
+  }
+
+  Collection<String> get keys {
+    // TODO: generate a lazy collection instead.
+    var attributes = _element.$dom_attributes;
+    var keys = new List<String>();
+    for (int i = 0, len = attributes.length; i < len; i++) {
+      if (_matches(attributes[i])) {
+        keys.add(attributes[i].$dom_localName);
+      }
+    }
+    return keys;
+  }
+
+  Collection<String> get values {
+    // TODO: generate a lazy collection instead.
+    var attributes = _element.$dom_attributes;
+    var values = new List<String>();
+    for (int i = 0, len = attributes.length; i < len; i++) {
+      if (_matches(attributes[i])) {
+        values.add(attributes[i].value);
+      }
+    }
+    return values;
+  }
+
+  /**
+   * Returns true if there is no {key, value} pair in the map.
+   */
+  bool get isEmpty {
+    return length == 0;
+  }
+
+  /**
+   * Checks to see if the node should be included in this map.
+   */
+  bool _matches(Node node);
+}
+
+/**
+ * Wrapper to expose [Element.attributes] as a typed map.
+ */
+class _ElementAttributeMap extends _AttributeMap {
+
+  final Element _element;
+
+  _ElementAttributeMap(this._element);
+
+  bool containsKey(String key) {
+    return _element.$dom_hasAttribute(key);
+  }
+
+  String operator [](String key) {
+    return _element.$dom_getAttribute(key);
+  }
+
+  void operator []=(String key, value) {
+    _element.$dom_setAttribute(key, '$value');
+  }
+
+  String remove(String key) {
+    String value = _element.$dom_getAttribute(key);
+    _element.$dom_removeAttribute(key);
+    return value;
+  }
+
+  /**
+   * The number of {key, value} pairs in the map.
+   */
+  int get length {
+    return keys.length;
+  }
+
+  bool _matches(Node node) => node.$dom_namespaceURI == null;
+}
+
+/**
+ * Wrapper to expose namespaced attributes as a typed map.
+ */
+class _NamespacedAttributeMap extends _AttributeMap {
+
+  final Element _element;
+  final String _namespace;
+
+  _NamespacedAttributeMap(this._element, this._namespace);
+
+  bool containsKey(String key) {
+    return _element.$dom_hasAttributeNS(_namespace, key);
+  }
+
+  String operator [](String key) {
+    return _element.$dom_getAttributeNS(_namespace, key);
+  }
+
+  void operator []=(String key, value) {
+    _element.$dom_setAttributeNS(_namespace, key, '$value');
+  }
+
+  String remove(String key) {
+    String value = this[key];
+    _element.$dom_removeAttributeNS(_namespace, key);
+    return value;
+  }
+
+  /**
+   * The number of {key, value} pairs in the map.
+   */
+  int get length {
+    return keys.length;
+  }
+
+  bool _matches(Node node) => node.$dom_namespaceURI == _namespace;
+}
+
+
+/**
+ * Provides a Map abstraction on top of data-* attributes, similar to the
+ * dataSet in the old DOM.
+ */
+class _DataAttributeMap implements Map<String, String> {
+
+  final Map<String, String> $dom_attributes;
+
+  _DataAttributeMap(this.$dom_attributes);
+
+  // interface Map
+
+  // TODO: Use lazy iterator when it is available on Map.
+  bool containsValue(String value) => values.some((v) => v == value);
+
+  bool containsKey(String key) => $dom_attributes.containsKey(_attr(key));
+
+  String operator [](String key) => $dom_attributes[_attr(key)];
+
+  void operator []=(String key, value) {
+    $dom_attributes[_attr(key)] = '$value';
+  }
+
+  String putIfAbsent(String key, String ifAbsent()) =>
+    $dom_attributes.putIfAbsent(_attr(key), ifAbsent);
+
+  String remove(String key) => $dom_attributes.remove(_attr(key));
+
+  void clear() {
+    // Needs to operate on a snapshot since we are mutating the collection.
+    for (String key in keys) {
+      remove(key);
+    }
+  }
+
+  void forEach(void f(String key, String value)) {
+    $dom_attributes.forEach((String key, String value) {
+      if (_matches(key)) {
+        f(_strip(key), value);
+      }
+    });
+  }
+
+  Collection<String> get keys {
+    final keys = new List<String>();
+    $dom_attributes.forEach((String key, String value) {
+      if (_matches(key)) {
+        keys.add(_strip(key));
+      }
+    });
+    return keys;
+  }
+
+  Collection<String> get values {
+    final values = new List<String>();
+    $dom_attributes.forEach((String key, String value) {
+      if (_matches(key)) {
+        values.add(value);
+      }
+    });
+    return values;
+  }
+
+  int get length => keys.length;
+
+  // TODO: Use lazy iterator when it is available on Map.
+  bool get isEmpty => length == 0;
+
+  // Helpers.
+  String _attr(String key) => 'data-$key';
+  bool _matches(String key) => key.startsWith('data-');
+  String _strip(String key) => key.substring(5);
+}