Difference between revisions of "HowTo:Create a new Relation"

Revision as of 17:43, 18 November 2013

A Relation is for a n:m relationship between various objects. On such a relational object additional data can be stored on its RELATIONDATA.

Navigate to the MetaClass RELATION in the Class Browser
Create a new instance using the Bulk Editor
It is required to set at least
- TARGETTYPELEFT: reference to the MetaClass of the right object of the relation
- TARGETTYPERIGHT: reference to the MetaClass of the left object of the relation
- RELATIONDATA: reference to the MetaClass used as template for the relational data
either by
- dragging and dropping a MetaClass object onto the cell
- selecting the desired MetaClass from the dialog appearing after double-clicking the cell
It is recommended to set at least name and description
Save the changes with Ctrl+S or the save command
As the relation data also a derivation of MetaClass RELATIONDATA can be used. For example to store more data on the relationship.

Relations have to be unqiue, so you can not create two relations with the same name!

The system creates an additional (but only internally used) MetaClass containing the relational data. This MetaClass will be created in the namespace System.Relation.Data

@@ Line 6: / Line 6: @@
 #* '''TARGETTYPERIGHT''': reference to the MetaClass of the left object of the relation
 #* '''RELATIONDATA''': reference to the MetaClass used as template for the relational data
+#: either by
+#* dragging and dropping a MetaClass object onto the cell
+#* selecting the desired MetaClass from the dialog appearing after double-clicking the cell
 # It is recommended to set at least name and description
 # Save the changes with {{key press|Ctrl|S}} or the save command