STI and has_many :through not playing nicely

rubyonrails-talk
1

Hi all,

I'm trying to use STI (single table inheritance) with has_many :through, and I'm getting a NameError: uninitialized constant. Details below. Presumably I've set up the relationship incorrectly? Any help would be greatly appreciated!

I have the following models:

class Activity < ActiveRecord::Base

  has_many :memberships   has_many :members, :through => :memberships

class Branch < Activity

class Member < ActiveRecord::Base

  has_many :memberships   has_many :activities, :through => :memberships

class Memberships < ActiveRecord::Base

  belongs_to :members   belongs_to :activities

I'm trying to run the following test (the activity fixture I'm testing is a branch):

class ActivityTest < Test::Unit::TestCase   fixtures :activities, :members, :memberships

  # Replace this with your real tests.   def test_has_member     assert_equal activities(:bristol).members.empty?, false   end end

and it's failing with:

NameError: uninitialized constant Activity::Membership

2

Tom Taylor wrote:

class Memberships < ActiveRecord::Base

  belongs_to :members   belongs_to :activities

You want

     belongs_to :member      belongs_to :activity

3

Thanks Mark, but I still get the same error. Any more suggestions?

Cheers,

Tom

4

Tom Taylor wrote:

5

Thanks, but alas, the same result...

Cheers,

Tom

6

The full stack trace is:

  1) Error: test_has_member(ActivityTest): NameError: uninitialized constant Activity::Membership     /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.2/lib/active_support/ dependencies.rb:477:in `const_missing'     /usr/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/ base.rb:1360:in `compute_type'     /usr/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/ reflection.rb:125:in `klass'     /usr/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/ reflection.rb:177:in `source_reflection'     /usr/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/ reflection.rb:177:in `source_reflection'     /usr/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/ reflection.rb:186:in `check_validity!'     /usr/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/ associations/has_many_through_association.rb:6:in `initialize'     /usr/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/ associations.rb:934:in `members'     ./test/unit/activity_test.rb:7:in `test_has_member'

7

Doh! I hadn't renamed memberships.rb to membership.rb. All fixed, thanks Mark!