public NavigationPropertyBindingConfiguration HasOptionalBinding <TTargetType, TDerivedEntityType>(
Expression <Func <TDerivedEntityType, TTargetType> > navigationExpression,
NavigationSourceConfiguration <TTargetType> targetEntitySet)
where TTargetType : class
where TDerivedEntityType : class, TEntityType
{
if (navigationExpression == null)
{
throw Error.ArgumentNull("navigationExpression");
}
if (targetEntitySet == null)
{
throw Error.ArgumentNull("targetEntitySet");
}
EntityTypeConfiguration <TDerivedEntityType> derivedEntityType =
_modelBuilder.EntityType <TDerivedEntityType>().DerivesFrom <TEntityType>();
NavigationPropertyConfiguration navigation = derivedEntityType.HasOptional(navigationExpression);
IList <MemberInfo> bindingPath = new List <MemberInfo>
{
TypeHelper.AsMemberInfo(typeof(TDerivedEntityType)),
navigation.PropertyInfo
};
return(this.Configuration.AddBinding(navigation, targetEntitySet.Configuration, bindingPath));
}
