public string this[string columnName] { get { string error = null; switch (columnName) { case "id": if (id == 0) { error = "Unique id required"; } break; case "task": if (!DataValidator.StringIsText(task) || !DataValidator.TextIsParagraphic(task)) //TextIsSentences { error = "Task text invalid"; } break; case "detail": //Details are not required if (detail == null) //string.IsNullOrWhiteSpace(detail) { error = "Detail text invalid"; } //if (!DataValidator.StringIsText(detail) || !DataValidator.TextIsParagraphic(detail)) //{ // error = "Detail text invalid"; //} break; } return(error); } }