How to use ActiveAdmin on models using has_many through association? - ruby-on-rails

Question

I am using ActiveAdmin gem in my project.
I have 2 models using has_many through association. The database schema looks exactly the same as the example in RailsGuide. http://guides.rubyonrails.org/association_basics.html#the-has_many-through-association
(source: rubyonrails.org)
How can I use ActiveAdmin to ...
show appointment date of each patient in physicians page?
edit appointment date of each patient in physicians page?
Thanks all. :)

Answer 1

For 1)
show do
panel "Patients" do
table_for physician.appointments do
column "name" do |appointment|
appointment.patient.name
end
column :appointment_date
end
end
end
For 2)
form do |f|
f.inputs "Details" do # physician's fields
f.input :name
end
f.has_many :appointments do |app_f|
app_f.inputs "Appointments" do
if !app_f.object.nil?
# show the destroy checkbox only if it is an existing appointment
# else, there's already dynamic JS to add / remove new appointments
app_f.input :_destroy, :as => :boolean, :label => "Destroy?"
end
app_f.input :patient # it should automatically generate a drop-down select to choose from your existing patients
app_f.input :appointment_date
end
end
end

Answer 2

In answer tomblomfield follow up question in comments:
Try the following in your AA ActiveAdmin.register Model do block:
controller do
def scoped_collection
YourModel.includes(:add_your_includes_here)
end
end
This should lazy load all your associations for each index page in a separate query
HTH

Answer 3

It should solve the N+1 query problem.
show do
panel "Patients" do
patients = physician.patients.includes(:appointments)
table_for patients do
column :name
column :appointment_date { |patient| patient.appointments.first.appointment_date }
end
end
end

Answer 4

It's work for me (with chosen)
permit_params category_ids: []
form do |f|
inputs 'Shop' do
input :category_ids, collection: Category.all.collect {|x| [x.name, x.id]}, as: :select, multiple: true, input_html: { class: "chosen-input", style: "width: 700px;"}
end
f.actions
end

Answer 5

#monfresh #tomblomfield you can do
has_many :appointments, ->{ includes(:patients) }, :through => :patients
in the physicians model
...or, I'm not sure if you can use it with formtastic but you could make the scope optional with something like
has_many :appointments :through => :patients do
def with_patients
includes(:patients)
end
end
and appointment.patient wont n+1 anymore

Answer 6

If you would like show multiple field in a panel row you can use following view:
show do |phy|
panel "Details" do
attributes_table do
... # Other fields come here
row :appointment_dates do
apps=""
phy.appointments.all.each do |app|
apps += app.patient.name + ":" + app.appoinment_date + ", "
end
apps.chomp(", ")
end
end
end
end
To place it in you redit form first put appointment_ids to permitted list:
permit_params: appointment_ids:[]
Add has many relationship to the form
form do |f|
f.has_many :appointments do |app|
app.inputs "Appointments" do
app.input :patients, :as => :select, :label => "Assigned Patients"
app.input :appointment_date
end
end
end
Should work if there is no coding error.

Answer 7

Regarding #2, it should be like this:
form do |f|
f.inputs 'Physician Details' do
f.input :name
end
f.inputs 'Physician Appointments' do
f.has_many :appointments,
heading: false,
new_record: 'Add new appointment',
remove_record: 'Delete appointment',
allow_destroy: true do |app|
app.input :patient, label: 'Choose the patient', collection: Patient.pluck(:name, :id)
app.input :appointment_date
end
end
Regarding the heading: - it can be false or some label (string)
Regarding the allow_destroy: - you can set it check for the user Administrator privilege's as can seen here
Important - In the Physician model, make sure to have
accepts_nested_attributes_for :appointments, allow_destroy: true
And, in the active admin model file - admin\physicians.rb - set this:
permit_params :name, appointments_attributes: [:patient_id, :_destroy, :id]