has_many through form driven by checkboxes - ruby

Question

Models : based on rails 3 guide!
class Physician < ActiveRecord::Base
has_many :physician_specialities
has_many :specialities, :through => :physician_specialities
end
class speciality < ActiveRecord::Base
has_many :physician_specialities
has_many :physicians, :through => :physician_specialities
end
class PhycianSpeciality < ActiveRecord::Base
belongs_to :physician
belongs_to :patient
end
And the database schema looks like this :
Physician
id
name
Speciality
id
name
PhycianSpeciality
id
physician_id
speciality_id
description
I want to have a form which is able to add specialities to a physician and write a small description of this speciality (according to the physician).
I think i can use somethings like this Quick Tip: has_many :through => checkboxes!
<% form_for #physician do -%>
<% Speciality.all.each do |group| -%>
<div>
<%= check_box_tag :speciality_ids, speciality.id, #user.specialities.include?(speciality), :name => 'user[speciality_ids][]' -%>
<%= label_tag :speciality_ids, speciality.name -%>
</div>
<% end -%>
<%= submit_tag -%>
<% end -%>
But i don't know where can i put the speciality description ...

Answer 1

It looks to me like you are missing at least two relationship tables/models.
SpecialtyDescription
PhysicianSpecialityDescription
That way you can have the right connection between PhysicianSpeciality & PhysicianSpecialityDescription (PhysicianSpeciality_id, SpecialtyDescription_id) & SpecialtyDescription.

Answer 2

Since the description is pending the creation of the join record in PhysicianSpecialty, I would just pass the description in as a text_area and sort it out pending the save of the Physician.
physicians_controller.rb
# i imagine ur update method would look kinda like this
def update
#physician = Physician.find(params[:id])
if #physician.update_attributes(params[:physician])
physician_specialty = PhysicianSpecialty.find_by_specialty_id(:specialty_id => specialty.id)
physician_specialty.update_attribute(:description, params[:description])
else
render :action => :edit
end
end