New column type: Reference value from more classes

05.01.2017

There is column type "Value from a referenced class" used for reference links between classes. This column can refer to a single class only and this class cannot be changed any more after column creation. In case you want to use more classes in the column, it is possible to refer to a common parent class.

However, in some cases inheritance is not possible or you do not want to create any coupling between classes. You can use a new column type "Value from a referenced class (various classes)" for these situations. When creating this column you define list of classes to which you will be able to refer in the column. You can change this list later on (add or remove classes). If you remove a class from the list of enabled classes, records will stay in the column. However, it will not be possible to add new references to the removed class. Deletion of such links can be performed by means of record filtering and mass change.

The column may be simple or multiple, same like for type "Value from a referenced class".




Example of use of this column is application for rental service of various objects. You can lend various items that differ in its type and therefore are stored in various ObjectGears classes, that do not have any relation one to another - e.g. cars, computers, CDs, books...You can easily add another type of lended objects into the rental service application later on. It means just adding one more class in the column definition.