*/
protected String getCheckedAttribute() throws Exception {
if (getContext().isMultiple(this)) {
GroupModel group = (GroupModel)getContext().getComponentData(this);
if (group == null) {
group = new DefaultGroupModel(getContext(), this);
getContext().putComponentData(this, group);
}
if (group.isSelected(getValue())) {
return "checked";
} else if (!group.isSelectionAvailable() && getChecked() != null) {