Datamapper DataMapper

Comments and changes to this ticket

• 

  Jonathan Stott (namelessjon) January 20th, 2010 @ 12:35 PM

  • State changed from “new” to “not-applicable”

  This is due to the lack of a discriminator property in the models.

• You flagged this item as spam.
  

  Robert Sköld January 21st, 2010 @ 03:32 AM

  I have an updated revision of that example: https://gist.github.com/31594a7c27768a9dc879/39e03de014b98c0c7e63ee...

  Now, even with a Discriminator, it still sets both of the association properties.

  The only difference in the example (besides adding a Discriminator) is that instead of setting only the Baby (the superclass) I set only the Child (the subclass) and in the queries it seems that the discriminator looks for both 'Baby' and 'Child' as type. Is this the expected behavior? Would the proper implementation be to use two separate subclasses instead of the "original" model and it's subclass?

• 

  Jonathan Stott (namelessjon) January 21st, 2010 @ 07:03 AM

  I think that is the expected behaviour. It's single table inheritance, so every Child instance should also act like a Baby instance. The Child might have more behaviour and more properties, but it should also act like a Baby.

      Child.new.is_a?(Baby)
      #=> true
  

  So any subclass of Baby is valid for has 1, :baby. To get the behaviour you want, you'll need two subclasses.