private List<PreValueItem> BuildPreValues(DataTypeDefinition dataTypeDefinition)
        {
            bool allEmpty = true;
            var prevalues = PreValues.GetPreValues(dataTypeDefinition.DataType.DataTypeDefinitionId);
            if (prevalues != null && prevalues.Count > 0)
            {
                var preValueItems = new List<PreValueItem>();
                foreach (DictionaryEntry item in prevalues)
                {
                    var preValue = item.Value as PreValue;
                    if (preValue != null)
                    {
                        var preValueItem = new PreValueItem()
                            {
                                Id = preValue.Id,
                                SortOrder = preValue.SortOrder,
                                Value = preValue.Value
                            };
                        preValueItems.Add(preValueItem);
                        if (!string.IsNullOrEmpty(preValueItem.Value)) allEmpty = false;
                    }

                }
                if (allEmpty) return null;

                return preValueItems;
            }
            return null;
        }
        private List<PreValueItem> BuildPreValues(DataTypeDefinition dataTypeDefinition)
        {
            try
            {
                bool allEmpty = true;
                var prevalues = PreValues.GetPreValues(dataTypeDefinition.DataType.DataTypeDefinitionId);
                if (prevalues != null && prevalues.Count > 0)
                {
                    var preValueItems = new List<PreValueItem>();
                    foreach (DictionaryEntry item in prevalues)
                    {
                        var preValue = item.Value as PreValue;
                        if (preValue != null)
                        {
                            var preValueItem = new PreValueItem()
                                {
                                    Id = preValue.Id,
                                    SortOrder = preValue.SortOrder,
                                    Value = preValue.Value
                                };
                            preValueItems.Add(preValueItem);
                            if (!string.IsNullOrEmpty(preValueItem.Value)) allEmpty = false;
                        }

                    }
                    if (allEmpty) return null;

                    return preValueItems;
                }
                return null;
            }
            catch (Exception ex)
            {
                throw new DataTypeException(string.Format("Data type {0} '{1}' prevalues could not be loaded.", dataTypeDefinition.Id.ToString(), dataTypeDefinition.Text), ex);
            }
        }