private static ExplorerEFElement GetNewOrExisting(
EditingContext context, EFElement efElement, ExplorerEFElement parent, Type viewModelType, bool mustNotExist)
{
var xref = GetModelToBrowserModelXRef(context);
var result = xref.GetExisting(efElement);
if (result != null)
{
if (mustNotExist)
{
Debug.Fail(
string.Format(
CultureInfo.CurrentCulture,
Resources.BadInsertChildAlreadyExists, efElement.GetType().FullName, parent.GetType().FullName));
return(null);
// TODO: we need to provide a general exception-handling mechanism and replace the above Assert()
// by e.g. the excepiton below
// throw new ArgumentException(string.Format(CultureInfo.CurrentCulture, Resources.BadInsertChildAlreadyExists, efElement.GetType().FullName, parent.GetType().FullName));
}
else
{
result.Parent = parent;
}
}
else
{
if (viewModelType != null)
{
if (!xref.IsDisplayedInExplorerProtected(efElement))
{
Debug.Fail(
"Attempting to create an ExplorerEFElement of type " + viewModelType.FullName +
" based on an EFElement which is not displayed in the Explorer " + efElement.ToPrettyString());
return(null);
}
result = Activator.CreateInstance(viewModelType, context, efElement, parent) as ExplorerEFElement;
xref.Add(efElement, result);
}
}
return(result);
}