public static IDataAncestorProvider GetDataAncestorProvider(IData data)
{
if (data == null)
{
throw new ArgumentNullException("data");
}
Type dataType = data.GetType();
var cache = _dataAncestorProviderCache;
IDataAncestorProvider dataAncestorProvider = cache[dataType];
if (dataAncestorProvider != null)
{
return(dataAncestorProvider);
}
lock (_syncRoot)
{
dataAncestorProvider = cache[dataType];
if (dataAncestorProvider != null)
{
return(dataAncestorProvider);
}
List <DataAncestorProviderAttribute> attributes = dataType.GetCustomInterfaceAttributes <DataAncestorProviderAttribute>().ToList();
if (attributes.Count == 0)
{
throw new InvalidOperationException(string.Format("Missing {0} attribute on the data type {1}", typeof(DataAncestorProviderAttribute), dataType));
}
if (attributes.Count > 1)
{
throw new InvalidOperationException(string.Format("Only one {0} attribute is allowed on the data type {1}", typeof(DataAncestorProviderAttribute), dataType));
}
DataAncestorProviderAttribute attribute = attributes[0];
if (attribute.DataAncestorProviderType == null)
{
throw new InvalidOperationException(string.Format("Data ancestor provider type can not be null on the data type {0}", data));
}
if (typeof(IDataAncestorProvider).IsAssignableFrom(attribute.DataAncestorProviderType) == false)
{
throw new InvalidOperationException(string.Format("Data ancestor provider {0} should implement the interface {1}", attribute.DataAncestorProviderType, typeof(IDataAncestorProvider)));
}
dataAncestorProvider = (IDataAncestorProvider)Activator.CreateInstance(attribute.DataAncestorProviderType);
cache.Add(dataType, dataAncestorProvider);
return(dataAncestorProvider);
}
}
public static IData GetParent(this IData data)
{
if (data == null)
{
throw new ArgumentNullException("data");
}
IDataAncestorProvider provider = DataAncestorProviderCache.GetDataAncestorProvider(data);
return(provider.GetParent(data));;
}
