Create new and select existing value from a has_many relationship - activeadmin

Question

Networks contains a has_one relationship for vlans.
Vlans contains a belongs_to relationship for networks.
When I create a new network, I want to have the option of either selecting an existing vlan by vlanid -or- creating a new vlan for the new network.
I have made it as far as being able to create a brand new vlan when I create a network, but I would like to be able to select an existing vlan -or- create a new one.
app/models/network.rb
class Network < ApplicationRecord
has_one :vlan
accepts_nested_attributes_for :vlan, allow_destroy: true
end
app/models/vlan.rb
class Vlan < ApplicationRecord
belongs_to :network
end
db/migrate/create_network.rb
class CreateNetworks < ActiveRecord::Migration[5.2]
def change
create_table :networks do |t|
t.string :comment
t.string :name
t.timestamps
end
end
end
db/migrate/create_vlan.rb
class CreateVlans < ActiveRecord::Migration[5.2]
def change
create_table :vlans do |t|
t.string :comment
t.integer :vlanid
t.belongs_to :network
t.timestamps
end
end
end
app/admin/networks.rb
ActiveAdmin.register Network do
permit_params :comment, :name, vlan_attributes: [ :id, :vlanid, :comment, :_destroy, :_edit ]
index do
selectable_column
column "Network Name" do |i|
i.name
end
column :comment
column "VLAN ID" do |i|
i.vlan.vlanid
end
column "VLAN Comment" do |i|
i.vlan.comment
end
actions
end
show do
attributes_table do
row :name
row :comment
end
panel 'vlan' do
table_for network.vlan do
column :vlanid
column :comment
end
end
end
form do |f|
f.inputs 'Details' do
f.input :name
f.input :comment
end
f.inputs 'Vlans' do
f.has_many :vlan do |c|
c.input :vlanid
c.input :comment
end
end
f.actions
end
end
app/admin/vlans.rb
ActiveAdmin.register Vlan do
belongs_to :network
permit_params :comment, :vlanid
end
I've tried using something like the following in app/admin/networks.rb
panel 'vlan' do
table_for network.vlan do
column :vlanid, :as => :select
column :comment
end
end
I do get a drop-down in this instance, but the only values are "Yes" and "No".
This is my first time delving into activeadmin and I'm stumped.
I've seen some similar questions posted around, but none of the answers I've seen seemed to apply to this specific situation.
Any help is appreciated.