Adding a link object
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Often, when you add to an association with a link class, you want to do things with the created link object. | Often, when you add to an association with a link class, you want to do things with the created link object. | ||
Do | Do this: | ||
[[File:Association_object.png|719x719px|border]] | [[File:Association_object.png|719x719px|border]] | ||
Add a method to either of the "main" classes with content similar to this | Add a method to either of the "main" classes with content similar to this: | ||
self.Flights.add(aFlight); | self.Flights.add(aFlight); | ||
self.Bookings->select(b | b.Flight = aFlight)->first | self.Bookings->select(b | b.Flight = aFlight)->first | ||
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. | 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 | Please note that it's usually good to set the names on the links, both the InnerLinkName and the LinkRoleName. | ||
In this example | In this example: this is the InnerLinkName and the LinkRoleName for the '''Person'''<nowiki/>'s end of the association. | ||
[[File:Linkrolename.png|none|frame]] | [[File:Linkrolename.png|none|frame]] | ||
Revision as of 08:12, 7 June 2023
Often, when you add to an association with a link class, you want to do things with the created link object.
Do this:
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
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's end of the association.
Note! From the Booking object, it's only one Person object in the association. Hence, Person, not Persons
See also: Association classes
This page was edited 87 days ago on 02/10/2024. What links here