ActiveAdmin nested has_many - ruby-on-rails

Question

Consider the following models:
class User < ApplicationRecord
accepts_nested_attributes_for :memberships, allow_destroy: true
has_many :memberships, dependent: :destroy
has_many :accounts, through: :memberships
end
class Account < ApplicationRecord
accepts_nested_attributes_for :memberships, allow_destroy: true
accepts_nested_attributes_for :users, allow_destroy: true
has_many :memberships, dependent: :destroy
has_many :users, through: :memberships
end
class Membership < ApplicationRecord
belongs_to :account
belongs_to :user
before_validation { self.role = "admin" if role.blank? }
validates :role, presence: true
pg_enum :role, %i[admin support user]
end
In ActiveAdmin there is already a form in place to create an Account and a Membership from an existing User. That looks like this:
form do |f|
...
f.inputs do
f.has_many :memberships, heading: false, allow_destroy: true, new_record: "Add existing user" do |m|
m.input :user_id, as: :searchable_select, ajax: { resource: User }
m.input :role, as: :select, label: false, include_blank: false
end
end
...
What I'm trying to do is update the form to allow a way to create an Account and a new User with a Membership with a specific role. This is what I've tried so far (within the same form block as the one above):
f.inputs do
f.has_many :users, heading: false, allow_destroy: true, new_record: "Add new user" do |u|
u.input :name
u.input :email, as: :string
u.has_many :memberships, heading: false, allow_destroy: true, new_record: "Add membership" do |m|
m.input :role, as: :select, label: false, include_blank: false
end
end
end
The form produced:
This doesn't work. If I don't fill in a role for the User's membership this will "work" and the before_validation in the Membership model will assign the User a Membership with role Admin. However, if I try to add a role to the User through the form and click "Create Account", then I am returned to the form where I see an error stating that Account must exist. This leads me to believe that the form is ignoring the second has_many that I've nested under f.has_many :users.
I've also tried approaching this by creating an input in the f.has_many :users block:
u.input :memberships, as: :select, label: "Role", include_blank: false, collection: Membership.roles
Instead of telling me that the Account must exist, this ignores any value I assign for the role, creates the User and assigns it a Membership with the role of Admin
How can I make this happen?

Answer 1

When you add through the form this is performed using JavaScript that includes before and after creation hooks I don't have an example but look at the code and see if it helps.