Self Referential has_many :through broken functionality?

Rails
1

Having set up my self referential user -> friend relationship with the
following code all seems to be working well except for one thing. Adding
and deleting friends. Here is the code for the models:
class Friendship < ActiveRecord::Base

belongs_to :friendshipped,
:foreign_key => “user_id”,
:class_name => “User”
belongs_to :befriendshipped,
:foreign_key => “friend_id”,
:class_name => “User”

end

class User < ActiveRecord::Base

has_many :friendships,
:foreign_key => ‘user_id’,
:class_name => ‘Friendship’
has_many :befriendships,
:foreign_key => ‘friend_id’,
:class_name => ‘Friendship’

has_many :friends,
:through => :friendships,
:source => :befriendshipped

has_many :befrienders,
:through => :befriendships,
:source => :friendshipped

end

When i execute the following code strange things happen:

user = User.find 1

friend = User.find 2

user.friends << friend

This piece of code appears to work but upon inspection of the generated
sql a friendship record is created with user_id = 2 where it should be 1
and the friend_id is set to NULL where it should be 2. It seems that
the ability to add friends to a user this way using self-referential
relationships is broken. Also deleting does not working either if i go
user.friends.delete(friend) an update statement is generated, very
confusing. I am not sure whats going on here at all. This functionality
works for normal has_many :through relationships just not my self
referential ones. Any ideas?

2

For anyone that may stumble upon this i have found a workaround although
i still believe it is a bug in rails.

When your self referential join is setup like above to add friends to a
user instead of using this :

  user = User.find 1

  friend = User.find 2

  user.friends << friend

Use this:

  user = User.find 1

  friend = User.find 2

  user.friendships.create(:user_id => user.id, :friend_id =>

friend.id)

For deleting instead of using this:

  user.friends.delete(friend)

Use this:

 user.friendships.destroy(user.friendships.find_by_friend_id(friend))

Hopefully this helps someone, any input from someone more experienced
than me is more than welcome, as i claim to be no expert.

3

I ave noticed this behaviour also. Can anyone confirm if this is a bug
or not ?? How does one confirm this.

4

I have created a plugin called Simply Rich Association that simplifies
the
self referential many to many relationship implementation. Check out the
Rubyforge for details:

http://sra.rubyforge.org

I am still working on setting up the Subversion repository. For now, you
can
unzip the file http://www.zepho.com/download/simply_rich_association.zip
into your vendor plugin directory.

5

@Bala P.

This is find for habtm but what about has_many :through for join tables
that need extra columns.