View source for Documentation:Adding a link object

Often, when you add to an association with a link class, you want to do things with the created link object.

Do this:

[[File:Association_object.png|719x719px|border]]

Add a method to either of the "main" classes with content similar to this:
 self.Flights.add(aFlight); 
 self.Bookings->select(b | b.Flight = aFlight)->first
There is an operator [[OCLOperators addReturnIndexOf0|addReturnIndexOf0]] that adds the Flight - and returns the zero based index of Booking.
 self.Bookings.at0(self.Flights.addReturnIndexOf0(aFlight)).AttributeOnBooking

It adds the object at the other end to the association and looks up the created link object - in this case, a Booking object and returns it.

Please note that it's usually good to set the names on the links, both the InnerLinkName and the LinkRoleName.

In this example: this is the InnerLinkName and the LinkRoleName for the '''Person'''<nowiki/>'s end of the association.
[[File:Linkrolename.png|none|frame]]

Note! From the '''Booking''' object, it's only '''one''' Person object in the association. Hence, '''Person''', not '''Persons'''

See also: [[Training:Association classes|Association classes]]
[[Category:UML]]
{{Edited|July|12|2024}}