/// <summary>
 /// Add a factor field enum value to the data identifier list.
 /// </summary>
 /// <param name='factorFieldEnumValue'>A factor field enum value.</param>
 public void Add(FactorFieldEnumValue factorFieldEnumValue)
 {
     if (factorFieldEnumValue.IsNotNull())
     {
         Add(new DataIdentifier(factorFieldEnumValue));
     }
 }
 private void SetEnumValue(FactorFieldEnumValue value)
 {
     CheckDataType(FactorFieldDataTypeId.Enum);
     if (value.IsNull())
     {
         _hasValue    = false;
         _stringValue = null;
     }
     else
     {
         if (IsTextField)
         {
             _stringValue = value.KeyText;
         }
         else
         {
             _numericValue = value.KeyInt;
         }
         _hasValue = true;
     }
 }
 /// <summary>
 /// Create a DataIdentifier instance with information from a
 /// factor field enum value.
 /// </summary>
 /// <param name='factorFieldEnumValue'>A factor field enum value.</param>
 public DataIdentifier(FactorFieldEnumValue factorFieldEnumValue)
 {
     _data       = factorFieldEnumValue;
     _dataType   = DataTypeId.FactorFieldEnumValue;
     _identifier = factorFieldEnumValue.Id.ToString();
 }