TypeError on sef-referential association

rubyonrails-talk
1

I have a self-referential association using the following two models:

class User < ActiveRecord::Base   has_many :incoming_friendships, :foreign_key => :user1_id, :class_name => :friendship   has_many :outgoing_friendships, :foreign_key => :user2_id, :class_name => :friendship   has_many :incoming_friends, :through => :outgoing_friendships   has_many :outgoing_friends, :through => :incoming_friendships   #... end

class Friendship < ActiveRecord::Base   belongs_to :user1, :class_name => :user, :foreign_key => :user1_id   belongs_to :user2, :class_name => :user, :foreign_key => :user2_id end

In theory (according to josh; has_many :through - Self-referential has_many :through associations) this should work fine. However, I'm having some trouble...

When using the console, I try the command "User.find(1).incoming_friends". This results in a TypeError;

User.find(1).incoming_friends

TypeError: can't convert Symbol into String from c:/Program Files/ruby/lib/ruby/gems/1.8/gems/activerecord-1.15.3/ lib/active_record/base.rb:1087:in `type_name_with_module' from c:/Program Files/ruby/lib/ruby/gems/1.8/gems/activerecord-1.15.3/ lib/active_record/base.rb:1356:in `compute_type' from c:/Program Files/ruby/lib/ruby/gems/1.8/gems/activerecord-1.15.3/ lib/active_record/reflection.rb:125:in `send' from c:/Program Files/ruby/lib/ruby/gems/1.8/gems/activerecord-1.15.3/ lib/active_record/reflection.rb:125:in `klass' from c:/Program Files/ruby/lib/ruby/gems/1.8/gems/activerecord-1.15.3/ lib/active_record/reflection.rb:177:in `source_reflection' from c:/Program Files/ruby/lib/ruby/gems/1.8/gems/activerecord-1.15.3/ lib/active_record/reflection.rb:177:in `collect' from c:/Program Files/ruby/lib/ruby/gems/1.8/gems/activerecord-1.15.3/ lib/active_record/reflection.rb:177:in `source_reflection' from c:/Program Files/ruby/lib/ruby/gems/1.8/gems/activerecord-1.15.3/ lib/active_record/reflection.rb:186:in `check_validity!' from c:/Program Files/ruby/lib/ruby/gems/1.8/gems/activerecord-1.15.3/ lib/active_record/associations/has_many_through_association.rb:6:in `initialize' from c:/Program Files/ruby/lib/ruby/gems/1.8/gems/activerecord-1.15.3/ lib/active_record/associations.rb:934:in `new' from c:/Program Files/ruby/lib/ruby/gems/1.8/gems/activerecord-1.15.3/ lib/active_record/associations.rb:934:in `incoming_friends' from (irb):1

If anyone has a clue what I might be doing wrong, I'd greatly appreciate some help!

2

I figured it out with help from somewhere else...for those who might be interested the solution was to name classnames and column names with strings, not symbols. It puzzles me why, but at least that solved my problem. So the two finished models looks like this:

class User < ActiveRecord::Base   #Friendship relations   has_many :incoming_friendships, :class_name => "Friendship", :foreign_key => "user1_id"   has_many :outgoing_friendships, :class_name => "Friendship", :foreign_key => "user2_id"   has_many :incoming_friends, :through => :outgoing_friendships, :source => :user1   has_many :outgoing_friends, :through => :incoming_friendships, :source => :user2

  def friends   incoming_friends.find(:all, :conditions => :confirmed != nil) + outgoing_friends.find(:all, :conditions => :confirmed != nil)   end end

class Friendship < ActiveRecord::Base   belongs_to :user1, :class_name => "User", :foreign_key => "user1_id"   belongs_to :user2, :class_name => "User", :foreign_key => "user2_id" end