Has many through : dynamic join on creation

Rails
1

Hello,

I have a User ActiveRecord model and a Group AR model joined by has_many
:through Membership. It’s not a HBTM because I need an extra attribute
for the memberships.

I tried to fill my dev site with some data added via a migration file. I
want to create two groups, and add a user to them. Below is the code I
use, and a description of the behaviour I don’t understand.

Code : - fold - unfold

  1. user = User.find_by_email(‘[email protected]’)
  3. group = Group.new
  4. group.title = “First group”
  5. group.save(false)
  7. membership = Membership.new
  8. membership.group = group
  9. membership.user = user
  10. membership.credit = 10
  11. membership.save(false)
  13. puts “membership 1”
  14. user.groups.each do |g| puts g.title end

  16. No problem here, output is :

  17. membership 1

  18. First group

  20. group2 = Group.new
  21. group2.title = “Second group”
  22. group2.save(false)
  24. membership2 = Membership.new
  25. membership2.group = group2
  26. membership2.user = user
  27. membership2.credit = 15
  28. membership2.save(false)
  30. puts “membership 2”
  31. user.lists.each do |g| puts g.title end

  33. Output is only :

  34. membership 2

  35. First group

  37. user2 = User.find_by_email(‘[email protected]’)
  39. puts “memberships”
  40. user2.groups.each do |g| puts g.title end

  42. Output is :

  43. memberships

  44. First group

  45. Second group

Why was my first group dynamically added to the user’s groups, and not
the second one ?

Thank you for your attention

2

Maybe a caching weirdness ?
Is my explanation clear enough ?