How to populate the has_many :through model table - ruby-on-rails

Question

My Models:
class Event < ActiveRecord::Base
belongs_to :organization
has_many :directors
has_many :vips, :through => :directors
end
class Vip < ActiveRecord::Base
belongs_to :organization
has_many :directors
has_many :events, :through => :directors
end
class Director < ActiveRecord::Base
belongs_to :vip
belongs_to :event
end
My New Event form:
<%= form_for [#organization, #event] do |f| %>
<p>
<%= f.label :when %>
<%= f.date_select :when %>
</p>
<p>
<%= f.label :name %>
<%= f.text_field :name %>
</p>
<p>
<%= f.label :vip %>
<%= f.select :vip_id, options_for_select(#organization.vips.all.map {|v| [v.name, v.id]}) %>
</p>
<p>
<%= f.submit %>
</p>
<% end %>
And my Events Controller:
def new
#organization = Organization.find(params[:organization_id])
#event = #organization.events.new
#director = Director.new
end
def create
#organization = Organization.find(params[:organization_id])
#event = #organization.events.build(event_params)
if #event.save
redirect_to organization_path(#organization)
else
render 'new'
end
end
So, my Vips are created earlier in the process and sit in the vips table. When I submit the new event form, I get a new entry to my events table just fine. What I want to do is have my directors table be populated with a new entry when I submit the new events form. The directors table would need the event_id of the event I just created, and the vip_id from the select tag in the form.
I thought about adding this to the create action
def create
#director = Director.new
if #event.save
redirect_to organization_path(#organization)
#director.vip_id = #event.vip_id
#director.event_id = #event.id
But that didn't create an entry into the director table. Is there a way to do this that I'm not seeing?

Answer 1

#director.vip_id = #event.vip_id
#director.event_id = #event.id
So, you have these two assignments, #director.event_id = #event.id this one is fine because you just created the event and you have the #event.id.
But, the first one won't work. Looking at your Model associations, #event does not have a vip_id, so you can't call #event.vip_id. You have to go to the vip through the organization, something like:
#event.organization.vips.first.vip_id
or, #event.vips.first.vip_id this would work too as you have :through => :directors association.
These two are the only way I see to get a valid vip_id corresponding to the event. Although, this will only get the first vip_id or you can specify some criteria in a where clause to get a particular vip_id for that event.
If that works for you, good. Otherwise, you may have to re-think your associations among the models.