public static FluentInclude <T> WithVirtualMList <T, L>(this FluentInclude <T> fi,
Expression <Func <T, MList <L> > > mListField,
Expression <Func <L, Lite <T>?> > backReference,
Action <L, T>?onSave = null,
Action <L, T>?onRemove = null,
bool?lazyRetrieve = null,
bool?lazyDelete = null) //To avoid StackOverflows
where T : Entity
where L : Entity
{
fi.SchemaBuilder.Include <L>();
var mListPropertRoute = PropertyRoute.Construct(mListField);
var backReferenceRoute = PropertyRoute.Construct(backReference, avoidLastCasting: true);
if (fi.SchemaBuilder.Settings.FieldAttribute <IgnoreAttribute>(mListPropertRoute) == null)
{
throw new InvalidOperationException($"The property {mListPropertRoute} should have an IgnoreAttribute to be used as Virtual MList");
}
RegisteredVirtualMLists.GetOrCreate(typeof(T)).Add(mListPropertRoute, new VirtualMListInfo(mListPropertRoute, backReferenceRoute));
var defLazyRetrieve = lazyRetrieve ?? (typeof(L) == typeof(T));
var defLazyDelete = lazyDelete ?? (typeof(L) == typeof(T));
Func <T, MList <L> > getMList = GetAccessor(mListField);
Action <L, Lite <T> >?setter = null;
bool preserveOrder = fi.SchemaBuilder.Settings.FieldAttributes(mListPropertRoute) !
.OfType <PreserveOrderAttribute>()
.Any();
if (preserveOrder && !typeof(ICanBeOrdered).IsAssignableFrom(typeof(L)))
{
throw new InvalidOperationException($"'{typeof(L).Name}' should implement '{nameof(ICanBeOrdered)}' because '{ReflectionTools.GetPropertyInfo(mListField).Name}' contains '[{nameof(PreserveOrderAttribute)}]'");
}
var sb = fi.SchemaBuilder;
if (defLazyRetrieve)
{
sb.Schema.EntityEvents <T>().Retrieved += (T e, PostRetrievingContext ctx) =>
{
if (ShouldAvoidMListType(typeof(L)))
{
return;
}
var mlist = getMList(e);
if (mlist == null)
{
return;
}
var query = Database.Query <L>()
.Where(line => backReference.Evaluate(line).Is(e.ToLite()));
MList <L> newList = preserveOrder ?
query.ToVirtualMListWithOrder() :
query.ToVirtualMList();
mlist.AssignAndPostRetrieving(newList, ctx);
};
}
if (preserveOrder)
{
sb.Schema.EntityEvents <T>().RegisterBinding <MList <L> >(mListField,
shouldSet: () => !defLazyRetrieve && !VirtualMList.ShouldAvoidMListType(typeof(L)),
valueExpression: (e, rowId) => Database.Query <L>().Where(line => backReference.Evaluate(line).Is(e.ToLite())).ExpandLite(line => backReference.Evaluate(line), ExpandLite.ToStringLazy).ToVirtualMListWithOrder(),
valueFunction: (e, rowId, retriever) => Schema.Current.CacheController <L>() !.Enabled ?
Schema.Current.CacheController <L>() !.RequestByBackReference <T>(retriever, backReference, e.ToLite()).ToVirtualMListWithOrder():
Database.Query <L>().Where(line => backReference.Evaluate(line).Is(e.ToLite())).ExpandLite(line => backReference.Evaluate(line), ExpandLite.ToStringLazy).ToVirtualMListWithOrder()
);
}
else
{
sb.Schema.EntityEvents <T>().RegisterBinding(mListField,
shouldSet: () => !defLazyRetrieve && !VirtualMList.ShouldAvoidMListType(typeof(L)),
valueExpression: (e, rowId) => Database.Query <L>().Where(line => backReference.Evaluate(line).Is(e.ToLite())).ExpandLite(line => backReference.Evaluate(line), ExpandLite.ToStringLazy).ToVirtualMList(),
valueFunction: (e, rowId, retriever) => Schema.Current.CacheController <L>() !.Enabled ?
Schema.Current.CacheController <L>() !.RequestByBackReference <T>(retriever, backReference, e.ToLite()).ToVirtualMList() :
Database.Query <L>().Where(line => backReference.Evaluate(line).Is(e.ToLite())).ExpandLite(line => backReference.Evaluate(line), ExpandLite.ToStringLazy).ToVirtualMList()
);
}
sb.Schema.EntityEvents <T>().PreSaving += (T e, PreSavingContext ctx) =>
{
if (VirtualMList.ShouldAvoidMListType(typeof(L)))
{
return;
}
var mlist = getMList(e);
if (mlist == null)
{
return;
}
if (mlist.Count > 0)
{
var graph = Saver.PreSaving(() => GraphExplorer.FromRoot(mlist).RemoveAllNodes(ctx.Graph));
GraphExplorer.PropagateModifications(graph.Inverse());
var errors = GraphExplorer.FullIntegrityCheck(graph);
if (errors != null)
{
#if DEBUG
var withEntites = errors.WithEntities(graph);
throw new IntegrityCheckException(withEntites);
#else
throw new IntegrityCheckException(errors);
#endif
}
}
if (mlist.IsGraphModified)
{
e.SetSelfModified();
}
};
sb.Schema.EntityEvents <T>().Saving += (T e) =>
{
if (VirtualMList.ShouldAvoidMListType(typeof(L)))
{
return;
}
var mlist = getMList(e);
if (mlist == null)
{
return;
}
if (preserveOrder)
{
mlist.ForEach((o, i) => ((ICanBeOrdered)o).Order = i);
}
if (GraphExplorer.IsGraphModified(mlist))
{
e.SetModified();
}
};
sb.Schema.EntityEvents <T>().Saved += (T e, SavedEventArgs args) =>
{
if (VirtualMList.ShouldAvoidMListType(typeof(L)))
{
return;
}
var mlist = getMList(e);
if (mlist != null && !GraphExplorer.IsGraphModified(mlist))
{
return;
}
if (!(args.WasNew || ShouldConsiderNew(typeof(T))))
{
var oldElements = mlist.EmptyIfNull().Where(line => !line.IsNew);
var query = Database.Query <L>()
.Where(p => backReference.Evaluate(p).Is(e.ToLite()));
if (onRemove == null)
{
query.Where(p => !oldElements.Contains(p)).UnsafeDelete();
}
else
{
query.Where(p => !oldElements.Contains(p)).ToList().ForEach(line => onRemove !(line, e));
}
}
if (mlist != null)
{
if (mlist.Any())
{
if (setter == null)
{
setter = CreateSetter(backReference);
}
mlist.ForEach(line => setter !(line, e.ToLite()));
if (onSave == null)
{
mlist.SaveList();
}
else
{
mlist.ForEach(line => { if (GraphExplorer.IsGraphModified(line))
{
onSave !(line, e);
}
});
}
var priv = (IMListPrivate)mlist;
for (int i = 0; i < mlist.Count; i++)
{
if (priv.GetRowId(i) == null)
{
priv.SetRowId(i, mlist[i].Id);
}
}
}
mlist.SetCleanModified(false);
}
};
sb.Schema.EntityEvents <T>().PreUnsafeDelete += query =>
{
if (VirtualMList.ShouldAvoidMListType(typeof(L)))
{
return(null);
}
//You can do a VirtualMList to itself at the table level, but there should not be cycles inside the instances
var toDelete = Database.Query <L>().Where(se => query.Any(e => backReference.Evaluate(se).Is(e)));
if (defLazyDelete)
{
if (toDelete.Any())
{
toDelete.UnsafeDelete();
}
}
else
{
toDelete.UnsafeDelete();
}
return(null);
};
return(fi);
}
public static FluentInclude <T> WithVirtualMListInitializeOnly <T, L>(this FluentInclude <T> fi,
Expression <Func <T, MList <L> > > mListField,
Expression <Func <L, Lite <T>?> > backReference,
Action <L, T>?onSave = null)
where T : Entity
where L : Entity
{
fi.SchemaBuilder.Include <L>();
Func <T, MList <L> > getMList = GetAccessor(mListField);
Action <L, Lite <T> >?setter = null;
var sb = fi.SchemaBuilder;
sb.Schema.EntityEvents <T>().RegisterBinding(mListField,
shouldSet: () => false,
valueExpression: (e, rowId) => Database.Query <L>().Where(line => backReference.Evaluate(line).Is(e.ToLite())).ExpandLite(line => backReference.Evaluate(line), ExpandLite.ToStringLazy).ToVirtualMListWithOrder()
);
sb.Schema.EntityEvents <T>().Saving += (T e) =>
{
if (VirtualMList.ShouldAvoidMListType(typeof(L)))
{
return;
}
var mlist = getMList(e);
if (mlist == null)
{
return;
}
if (GraphExplorer.IsGraphModified(getMList(e)))
{
e.SetModified();
}
};
sb.Schema.EntityEvents <T>().Saved += (T e, SavedEventArgs args) =>
{
if (VirtualMList.ShouldAvoidMListType(typeof(L)))
{
return;
}
var mlist = getMList(e);
if (mlist == null)
{
return;
}
if (!GraphExplorer.IsGraphModified(mlist))
{
return;
}
if (setter == null)
{
setter = CreateSetter(backReference);
}
mlist.ForEach(line => setter !(line, e.ToLite()));
if (onSave == null)
{
mlist.SaveList();
}
else
{
mlist.ForEach(line =>
{
if (GraphExplorer.IsGraphModified(line))
{
onSave !(line, e);
}
});
}
var priv = (IMListPrivate)mlist;
for (int i = 0; i < mlist.Count; i++)
{
if (priv.GetRowId(i) == null)
{
priv.SetRowId(i, mlist[i].Id);
}
}
mlist.SetCleanModified(false);
};
return(fi);
}
