/// <summary>
/// Gets an enumerable collection of children of a given type.
/// </summary>
/// <param name="childType">Type of children to get.</param>
/// <returns>A collection of children.</returns>
/// <exception cref="ArgumentException">Thrown if the type isn't a valid child type.</exception>
public IEnumerable Filter(Type childType)
{
foreach (object container in this.items)
{
CollectionItem collectionItem = container as CollectionItem;
if (collectionItem != null)
{
if (collectionItem.ElementType.IsAssignableFrom(childType))
{
return(collectionItem.Elements);
}
continue;
}
ElementCollection elementCollection = container as ElementCollection;
if (elementCollection != null)
{
IEnumerable nestedFilter = elementCollection.Filter(childType);
if (nestedFilter != null)
{
return(nestedFilter);
}
continue;
}
}
throw new ArgumentException(String.Format(
CultureInfo.InvariantCulture,
"Type {0} is not valid for this collection.",
childType.Name));
}
