Question

I have in form this code line <%= f.collection_select :owner_ids, Owner.order(:id), :id, :name, {}, {multiple: true} %> that returns the list of owners in the massmedium form, but I need in this field also to include the companies too, so I could have in the same list the companies too, cause a massmedia chanel could be owned by a person or by a company.

Company.rb

class Company < ActiveRecord::Base

  has_many :ownerships
  has_many :massmedia, through: :ownerships
  has_many :owners, through: :ownerships
end

Owner.rb

class Owner < ActiveRecord::Base

  has_many :ownerships
  has_many :massmedia, through: :ownerships
  has_many :companies, through: :ownerships
end

Massmedium.rb

class Massmedium < ActiveRecord::Base
  belongs_to :category

  has_many :ownerships
  has_many :owners, through: :ownerships
  has_many :companies, through: :ownerships

end

Answer 1

= f.select :owners, options_for_select((Owner.all + Company.all)
  .collect{|o| [o.name, "#{o.class},#{o.id}"], {multiple: true}

u have to define owners=(values) method in your model, which will parse values like [“Company,1″,”Owner,2”]