newbie trying self-referencing :through via REST model

rubyonrails-talk
1

I've read through countless blogs and the docs and can't seem to get what I expect. I also tried irc on freenode, but they ignored me. I must have a case of the mange or something.

I have a Person model (on a people table) and I want a hierarchy of masters and servants. I'm doing this via a Vassalship model. When I try to assign a master to a servant like so :

     juniorperson.master=seniorperson

I get NoMethodError: undefined method `update_attributes' for #<Class: 0x48be738>

And who knows what class that was. I can do seniorperson.servants<<juniorperson no problem, but then I get a nil for juniorperson.master ?!?!

My models look like this :

class Person < ActiveRecord::Base    has_many :vassalships,:class_name=>'Vassalship',:foreign_key=>:master_id   has_one :master,:through=>:vassalships,:source=>:master;   has_many :servants,:through=>:vassalships,:source=>:servant; end

class Vassalship < ActiveRecord::Base   belongs_to :master,:class_name=>'Person',:foreign_key=>'master_id'   belongs_to :servant,:class_name=>'Person',:foreign_key=>'servant_id' end

my tables are here, if you need to see them: http://pastie.org/352858, and the full console track is here : http://pastie.org/352871

I'm doing something wrong, but I don't know what. And anyone got a better idea for the relationship? Vassalship seems a bit obscure.

2

You only need one model, Person should suffice:

class Person < ActiveRecord::Base

  belongs_to :master, :class_name => 'Person', :foreign_key => 'master_id'

  has_many :servants, :class_name => 'Person', :foreign_key => 'master_id'

end

Let me know how you get on.

Regards, Franz

3

I have a need for REST (as well as other things), as mentioned, and for that I require the go-between model. In anycase presumably my original question does have an answer, no? Perhaps :through does not work self-referentially, although I would be surprised. But the docs don;t have it and blogs haven't helped.

4

try:

class Person < ActiveRecord::Base

has_many :vassalships,:class_name=>'Vassalship',:foreign_key=>'master_id'         has_many :vassalship_belongings, :class_name => 'Vassalship', :foreign_key => 'slave_id'         has_one :master,:through=>:vassalships,:source=>:person

has_many :servants,:through=>:vassalship_belongings,:source=>:person end

class Vassalship < ActiveRecord::Base

belongs_to :master,:class_name=>'Person',:foreign_key=>'master_id'

belongs_to :servant,:class_name=>'Person',:foreign_key=>'servant_id' end