dart:html
dataset property Map<String, String> dataset  Allows access to all custom data attributes (data-*) set on this element. The keys for the map must follow these rules:

The name must not begin with 'xml'.
The name cannot contain a semi-colon (';').
The name cannot contain any capital letters.
 Any keys from markup will be converted to camel-cased keys in the map. For example, HTML specified as: <div data-my-random-value='value'></div>
 Would be accessed in Dart as: var value = element.dataset['myRandomValue'];
 See also:
Custom data attributes Source  Map<String, String> get dataset => new _DataAttributeMap(attributes);    void dataset=(Map<String, String> value)    Source  set dataset(Map<String, String> value) {
  final data = this.dataset;
  data.clear();
  for (String key in value.keys) {
    data[key] = value[key];
  }
}

    
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