Question

I have a has_many through relationship between Course and User.

class Course < ActiveRecord::Base
  belongs_to :user

  has_many :enrollments, :dependent => :delete_all
  has_many :users, :through => :enrollments

  attr_accessible :description, :duration, :name, :prerequisites, :short_name, :start_date, :user_id

  accepts_nested_attributes_for :users, :allow_destroy => true
  attr_accessible :users_attributes

and User:

class User < ActiveRecord::Base

has_many :subjects, :class_name => "Course"  # to get this call user.subjects
has_many :enrollments, :dependent => :delete_all
has_many :courses, :through => :enrollments

and Enrollment:

class Enrollment < ActiveRecord::Base

belongs_to :course
belongs_to :user

attr_accessible :course_id, :user_id

end

Now I’m trying to set user_ids from inside Course, using a nested form. It keeps giving me that Mass Assignment warning, and nothing is saved. I read I was supposed to add attr_accessible user_id but it still doesn’t work.

Even if I do something like this from the rails console:

@c.update_attributes({:user_ids => [7,8]})

with @c being the course

Any help would be greatly appreciated,
Thank you.

Answer 1

It’s user_ids, not user_id.

You need to add user_ids to your attr_accessible.