private void ValidateAdapter(Type adapterType, Type propertyType)
{
//check that it implements the right interface
if (!adapterType.ImplementsGeneric(typeof(ICollectionAdapter <,>)))
{
throw CollectionException.InvalidAdapterType(adapterType);
}
//check that it matches the property type
var boundGenericType = adapterType.GetBoundGenericInterface(typeof(ICollectionAdapter <,>));
var tCollectionArgument = boundGenericType.GenericTypeArguments[0];
//if an instance of propertyType cannot be assigned to the type argument TCollection, throw an exceptions
if (!tCollectionArgument.GetTypeInfo()
.IsAssignableFrom(propertyType.GetTypeInfo()))
{
throw CollectionException.AdapterTypeMismatch(adapterType, boundGenericType, propertyType);
}
}
private void Validate(IEnumerable <MementoCollectionAttribute> attrs, Type propertyType)
{
//Checks whether the property type implements ICollection<T>.
//This check should be done on the declared property type (instead of the runtime object type).
bool isCollection = propertyType.IsCollection();
bool hasAdapter = false;
Type adapterType = null;
if (attrs != null)
{
//Find an attribute with an adapter type
MementoCollectionAttribute attr = attrs.FirstOrDefault(a => a.CollectionAdapterType != null);
if (attr != null)
{
//get adapter type
adapterType = attr.CollectionAdapterType;
ValidateAdapter(adapterType, propertyType);
hasAdapter = true;
//wrap collection in adapter
AdaptCollection(adapterType);
}
}
//if its not a valid collection and a valid adapter was not supplied
if (!isCollection && !hasAdapter)
{
throw CollectionException.IsNotCollection(propertyType);
}
//fetch element type
if (isCollection)
{
ElementType = propertyType.GetCollectionElementType();
}
if (hasAdapter)
{
ElementType = adapterType.GetAdapterElementType();
}
}
private void AdaptCollection(Type adapterType)
{
dynamic adapter;
try
{
adapter = new DynamicInvoker(Activator.CreateInstance(adapterType));
}
catch (MissingMemberException ex)
{
throw CollectionException.FailedAdapterActivation(adapterType, ex);
}
if (Collection != null)
{
//initialize adapter
adapter.Collection = Collection;
//replace collection with adapter
Collection = adapter.InnerObject;
}
}