Has_only_one or has_mate

Rails
1

Hello fellow Railers,

I wonder if somebody implemented such behaviour already:

maria.friend = peter

and then automatically this would happen with peter

peter.friend = maria

Similar:

maria.friend = nil

would set whatever maria.friend was before to nil too, so:
peter.friend = nil

Does anybody know how I could extend has_one to such has_only_one
behaviour?

Thanks, folks!
Phil

2

has_one means that the entity has 0 or 1. It is a “has only one.”

It looks like you’re trying a self-referencing relationship. Make sure
the
Person (assuming) model has both has_one and belongs_to methods.

Something like:

has_one :friend, :class => ‘Person’
belongs_to :person

3

Derek Perrault wrote:

Oops…

has_one :friend, :class => ‘Person’
belongs_to :person, :foreign_key => ‘friend’

I will try this, thanks Derek!

4

Oops…

has_one :friend, :class => ‘Person’
belongs_to :person, :foreign_key => ‘friend’