/// <summary>
/// Verifies that the <see cref="MetadataTypeAttribute"/> reference does not contain a cyclic reference and
/// registers the AssociatedMetadataTypeTypeDescriptionProvider in that case.
/// </summary>
/// <param name="type">The entity type with the MetadataType attribute.</param>
private static void RegisterAssociatedMetadataTypeTypeDescriptor(Type type)
{
Type currentType = type;
HashSet <Type> metadataTypeReferences = new HashSet <Type>();
metadataTypeReferences.Add(currentType);
while (true)
{
MetadataTypeAttribute attribute = (MetadataTypeAttribute)Attribute.GetCustomAttribute(currentType, typeof(MetadataTypeAttribute));
if (attribute == null)
{
break;
}
else
{
currentType = attribute.MetadataClassType;
// If we find a cyclic reference, throw an error.
if (metadataTypeReferences.Contains(currentType))
{
throw new InvalidOperationException(String.Format(CultureInfo.CurrentCulture, Resource.CyclicMetadataTypeAttributesFound, type.FullName));
}
else
{
metadataTypeReferences.Add(currentType);
}
}
}
// If the MetadataType reference chain doesn't contain a cycle, register the use of the AssociatedMetadataTypeTypeDescriptionProvider.
DomainServiceDescription.RegisterCustomTypeDescriptor(new AssociatedMetadataTypeTypeDescriptionProvider(type), type);
}