zonedesigner.cs

        public string ZoneDataJSON
        {
            get
            {
                var newCount = 0L;
                if (EntityInstance.IsNew()) return BlankZoneDataJSON;
                var members = IoCContainer.Resolve<IZoneService>().
                    GetImmediateZoneMembers(this.EntityId).ToList<IZoneMember>().
                    Select(mem => new
                    {
                        id = mem.ZoneMemberId,
                        type = GetZoneMemberTypeName(mem.TableCatalogId),
                        entityId = GetMemberId(mem.EntityPrimaryKeyId, ref newCount),
                        pathData = mem.PathData,
                        transformation = mem.Transformation
                    }).ToArray();
                return new JavaScriptSerializer().Serialize(new
                {
                    floorPlanId = this.EntityInstance.ConceptDocumentId,
                    members = members
                });
            }
        }

        private long GetMemberId(long entityPrimaryKeyId, ref long newCount)
        {
            if (entityPrimaryKeyId <= 0)
            {
                if (entityPrimaryKeyId < newCount)
                    newCount = entityPrimaryKeyId;
                else
                    entityPrimaryKeyId = --newCount;
            }
            return entityPrimaryKeyId;
        }