/// <summary>
/// Special version of <see cref="ICloneOperation.HandleObject"/> for cases where the target object graph alreay
/// exists and it is undesireable for a source value of null to overwrite a non-null target value.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="operation"></param>
/// <param name="source"></param>
/// <param name="target"></param>
/// <param name="dontNullifyExternal"></param>
/// <returns></returns>
public static void HandleObject <T>(this ICloneOperation operation, T source, ref T target, bool dontNullifyExternal) where T : class
{
if (object.ReferenceEquals(source, null) && dontNullifyExternal && !operation.IsTarget(target))
{
return;
}
operation.HandleObject(source, ref target);
}
public override void CreateTargetObjectLate(Delegate source, ref Delegate target, ICloneOperation operation)
{
Delegate[] sourceInvokeList = (source != null) ? source.GetInvocationList() : null;
Delegate[] targetInvokeList = (target != null) ? target.GetInvocationList() : null;
RawList <Delegate> mergedInvokeList = new RawList <Delegate>(
((sourceInvokeList != null) ? sourceInvokeList.Length : 0) +
((targetInvokeList != null) ? targetInvokeList.Length : 0));
// Iterate over our sources invocation list and copy entries are part of the target object graph
if (sourceInvokeList != null)
{
for (int i = 0; i < sourceInvokeList.Length; i++)
{
if (sourceInvokeList[i].Target == null)
{
continue;
}
object invokeTargetObject = null;
if (operation.GetTarget(sourceInvokeList[i].Target, ref invokeTargetObject))
{
MethodInfo method = sourceInvokeList[i].GetMethodInfo();
Delegate targetSubDelegate = method.CreateDelegate(sourceInvokeList[i].GetType(), invokeTargetObject);
mergedInvokeList.Add(targetSubDelegate);
}
}
}
// Iterate over our targets invocation list and keep entries that are NOT part of the target object graph
if (targetInvokeList != null)
{
for (int i = 0; i < targetInvokeList.Length; i++)
{
if (targetInvokeList[i].Target == null)
{
continue;
}
if (!operation.IsTarget(targetInvokeList[i].Target))
{
MethodInfo method = targetInvokeList[i].GetMethodInfo();
Delegate targetSubDelegate = method.CreateDelegate(targetInvokeList[i].GetType(), targetInvokeList[i].Target);
mergedInvokeList.Add(targetSubDelegate);
}
}
}
// Create a new delegate instance
Delegate[] mergedInvokeArray = mergedInvokeList.Data;
if (mergedInvokeArray.Length != mergedInvokeList.Count)
{
Array.Resize(ref mergedInvokeArray, mergedInvokeList.Count);
}
target = Delegate.Combine(mergedInvokeArray);
}