public CollectionMappingFeature(IEquivalentComparer equivalentComparer)
{
EquivalentComparer = equivalentComparer;
}
public static TDestination Map <TSource, TSourceItem, TDestination, TDestinationItem>(TSource source, TDestination destination, ResolutionContext context, IEquivalentComparer equivalentComparer)
where TSource : IEnumerable <TSourceItem>
where TDestination : ICollection <TDestinationItem>
{
if (source == null || destination == null)
{
return(destination);
}
var destList = destination.ToLookup(x => equivalentComparer.GetHashCode(x)).ToDictionary(x => x.Key, x => x.ToList());
var items = source.Select(x =>
{
var sourceHash = equivalentComparer.GetHashCode(x);
var item = default(TDestinationItem);
List <TDestinationItem> itemList;
if (destList.TryGetValue(sourceHash, out itemList))
{
item = itemList.FirstOrDefault(dest => equivalentComparer.IsEquivalent(x, dest));
if (item != null)
{
itemList.Remove(item);
}
}
return(new { SourceItem = x, DestinationItem = item });
});
foreach (var keypair in items)
{
if (keypair.DestinationItem == null)
{
destination.Add((TDestinationItem)context.Mapper.Map(keypair.SourceItem, null, typeof(TSourceItem), typeof(TDestinationItem)));
}
else
{
context.Mapper.Map(keypair.SourceItem, keypair.DestinationItem);
}
}
foreach (var removedItem in destList.SelectMany(x => x.Value))
{
destination.Remove(removedItem);
}
return(destination);
}
static EquivalentExpression()
{
BadValue = new EquivalentExpression();
}
public static Expression <Func <TDestination, bool> > Map <TSource, TDestination>(TSource source, IEquivalentComparer <TSource, TDestination> toSourceExpression)
{
return(toSourceExpression.ToSingleSourceExpression(source));
}