Rails active admin for a has_many through association

Question

How can I display the extra attribute of the join model(in a has_many through association), in active_admin forms?

f.input :ad_slots

Will only display the ad_slots model, but I have a join table called stream_slots which has an extra column called duration. I want to be able to choose an ad_slot as well as enter the duration.

These are the models:

#live_stream:
has_many :stream_slots, :dependent => :destroy
has_many :ad_slots, :through => :stream_slots

#ad_slot:
has_many :stream_slots, :dependent => :destroy
has_many :live_streams, :through => :stream_slots

#stream_slot:
belongs_to :ad_slot
belongs_to :live_stream

and stream_slot has the ids of the other two models as well as an extra attribute called duration.

Thank you.

-- Tried something else--

Instead of linking to ad_slots, this is what I did:

f.has_many :stream_slots do |association|
  association.inputs do 
    association.input :ad_slot
    association.input :duration
  end

end

and in LiveStream class, I added:

accepts_nested_attributes_for :stream_slots

This way the form shows the ad_slots for me to choose from, as well as a text field for the extra attribute, however, It fails when I try to save it. I believe I know what the problem is but I don't know how to solve it. It's because the live_stream_id in the stream_slots table is empty. How do set it to the newly created live_stream? (The one I'm creating now..)

Any help would be appreciated..

Answer 1

I got it working, As mentioned in the question the problem was that when the form was submitted, the live_stream_id was empty.

So I just removed the validation in the stream_slot model which says that the live_stream_id must be present and it worked.

Not sure if that's the best way to do it.. but it's working for now.

If anyone has a better solution, please share.