object GetValueFor([NotNull] LocationInterceptionArgs args, LazyEntity parent, Func <LazyEntity, Type, ICollection <IDataCriterion>, IEnumerable <object> > read)
{
var criterion = CriterionFor(args);
if (criterion == null)
{
return(null);
}
// var collection = GetLazy.Entity(RealLocationType, (ILazyEntity)args.Instance).By(criterion);
var collection = read(parent, RealLocationType, new[] { criterion });
if (IsCollection)
{
var targetCollection = (IList)Activator.CreateInstance(TargetCollectionType);
foreach (var item in collection)
{
targetCollection.Add(item);
}
return(targetCollection);
}
return(collection.FirstOrDefault());
}
void LazyLoadValueFromDatabase(LocationInterceptionArgs args, LazyEntity lazyEntity)
{
lock (_writeLock) {
args.ProceedGetValue();
if (AlreadyLoaded)
{
return;
}
if (IsValueAlreadySpecified(args))
{
AlreadyLoaded = true;
return;
}
if (lazyEntity.Read == null)
{
AlreadyLoaded = true; //?if Read callback is null - it means that entity was created by the client code, and not was getted from db, so it's not persisted at all.
return;
}
var value = GetValueFor(args, lazyEntity, lazyEntity.Read);
args.SetNewValue(value);
AlreadyLoaded = true;
args.ProceedGetValue();
}
}
void CopyLazyContext(LazyEntity parent, object entity)
{
var lazyEntity = entity as LazyEntity;
if (lazyEntity != null)
{
lazyEntity.Context = parent.Context;
SafetySetReadCallbackTo(lazyEntity);
}
}
IEnumerable <object> LazyLoad(LazyEntity parent, Type type, ICollection <IDataCriterion> criteria)
{
var info = _lazyFactory.InfoAbout(type);
var repository = _lazyFactory.ReadingRepository();
foreach (var item in repository.Read(info, criteria))
{
CopyLazyContext(parent, item);
yield return(item);
}
}
void SafetySetReadCallbackTo(LazyEntity entity)
{
if (entity.Read == null)
{
lock (entity) {
if (entity.Read == null)
{
entity.Read = LazyLoad;
}
}
}
}
void SetupLazyChildren(LazyEntity entity, IEntityInfo info, LazyEntity.LoadingContext context)
{
if (entity == null)
{
return;
}
entity.Context = context;
SafetySetReadCallbackTo(entity);
if (info.Inclusions == null)
{
return;
}
foreach (var inclusion in info.Inclusions)
{
object child;
if (!entity.TryGet(inclusion.TargetPath, out child))
{
Log.TraceEvent(TraceEventType.Warning, $"Can't get property {inclusion.TargetPath} on {_mainEntityInfo.EntityType} to setup it's loading context.");
continue;
}
if (child == null)
{
continue;
}
if (!inclusion.IsCollection)
{
SetupLazyChildren(child as LazyEntity, inclusion.Info, context);
continue;
}
foreach (var item in (IEnumerable)child)
{
SetupLazyChildren(item as LazyEntity, inclusion.Info, context);
}
}
}
