Nested form in active_admin with select or create option

Question

We are using active_admin for our administration backend.

We have a model "App" that :belongs_to model "Publisher":

class App < ActiveRecord::Base
  belongs_to :publisher
end

class Publisher < ActiveRecord::Base
  has_many :apps
end

When creating a new entry for the "App" model I want to have the option to either select an existing publisher or (if the publisher is not yet created) to create a new publisher in the same (nested) form (or at least without leaving the page).

Is there a way to do this in active_admin?

Here's what we have so far (in admin/app.rb):

form :html => { :enctype => "multipart/form-data" } do |f|
  f.inputs do
    f.input :title
    ...
  end

  f.inputs do
    f.semantic_fields_for :publisher do |p| # this is for has_many assocs, right?
      p.input :name
    end
  end

  f.buttons
end

After hours of searching, I'd appreciate any hint... Thanks!

Did you ever manage to do this? I'm trying to do the exact same thing now :-/ — Chris Edwards, Sep 24 '12 at 10:29

score 9 · Answer 1 · edited Feb 03 '15 at 17:41

9

First, make sure that in your Publisher model you have the right permissions for the associated object:

class App < ActiveRecord::Base
  attr_accessible :publisher_attributes

  belongs_to :publisher
  accepts_nested_attributes_for :publisher, reject_if: :all_blank
end

Then in your ActiveAdmin file:

form do |f|
  f.inputs do
    f.input :title
    # ...
  end

  f.inputs do
    # Output the collection to select from the existing publishers
    f.input :publisher # It's that simple :)

    # Then the form to create a new one
    f.object.publisher.build # Needed to create the new instance
    f.semantic_fields_for :publisher do |p|
      p.input :name
    end
  end

  f.buttons
end

I'm using a slightly different setup in my app (a has_and_belongs_to_many relationship instead), but I managed to get it working for me. Let me know if this code outputs any errors.

edited Feb 03 '15 at 17:41

Dorian

22,759
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answered Nov 01 '12 at 22:11

Cristian

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1

I tried something equivalent and ended up with an "undefined method `build' for nil:NilClass" using rails 3.1.10 ; am I too far behind ? – Bastes Jan 09 '13 at 14:37
1

first make sure the relation is set up correctly. In the example above, `App` belongs to `publisher`. If you have the relationship type many, you'll have to use `publishers` instead. Otherwise I guess you can read here http://stackoverflow.com/questions/783584/ruby-on-rails-how-do-i-use-the-active-record-build-method-in-a-belongs-to-rel and maybe you'll have to use `f.object.build_publisher` instead. Let me know if it works, maybe I have to update my answer... – Cristian Jan 09 '13 at 18:41
Can u share code for has_many. I want a selectable list of dropdown publishers for an app – Pinser Jul 28 '14 at 08:12

score 7 · Answer 2 · answered Sep 06 '11 at 04:55

The form_builder class supports a method called has_many.

f.inputs do
  f.has_many :publisher do |p|
    p.input :name
  end
end

That should do the job.

Update: I re-read your question and this only allows to add a new publisher, I am not sure how to have a select or create though.

score 5 · Answer 3 · edited Feb 03 '15 at 17:44

5

According to ActiveAdmin: http://activeadmin.info/docs/5-forms.html

You just need to do as below:

f.input :publisher

edited Feb 03 '15 at 17:44

Dorian

22,759
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answered Aug 16 '12 at 09:59

datnt

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score 0 · Answer 4 · edited Feb 15 '19 at 09:37

I've found you need to do 3 things.

Add semantic fields for the form

f.semantic_fields_for :publisher do |j|
  j.input :name
end

Add a nested_belongs_to statement to the controller

controller do
    nested_belongs_to :publisher, optional: true
end

Update your permitted parameters on the controller to accept the parameters, using the keyword attributes

permit_params publisher_attributes:[:id, :name]

Nested form in active_admin with select or create option

4 Answers4