public void SetParentSubset(IColumnSubsetInfo <T> parent)
{
if (GetParentSubset() != null)
{
throw new Exception($"Subset {this} already has a parent subset.");
}
_parent = parent;
// when assigning a parent, remove all columns inherited from this parent, so a 'derived' object contains only its own columns
_columns = _columns.Except(parent.GetColumns()).ToList();
}
public override string ToString()
{
//return $"ID={GetId()}, Parent={(_parent!=null ? String.Join(",", _parent?.GetColumns()) : null)}, Columns={String.Join(",", _columns)}";
//let's output subsets with their hierarcy
var str = $"({String.Join(",", GetColumns())})";
for (IColumnSubsetInfo <T> subset = this; subset.GetParentSubset() != null; subset = subset.GetParentSubset())
{
str += $" -> ({String.Join(",", subset.GetParentSubset().GetColumns())})";
}
return(str);
}
