Nested form in activeadmin not saving updates

activeadmin, forms, formtastic, ruby-on-rails, ruby-on-rails-4

Solution

You need to permit nested parameters, but you should never use `params.permit!`. It's extremely unsafe. Try this:

ActiveAdmin.register ClassSection do
  permit_params :max_students, :min_students, :info, :class_course_id, :location_id, 
                class_dates_attributes: [ :id, :start_time, :end_time, :_destroy ]

  form do |f|
    # ...
    f.inputs "Dates" do
      f.has_many :class_dates, heading: false, allow_destroy: true do |cd|
        cd.input :start_time, :as => :datetime_picker
        cd.input :end_time, :as => :datetime_picker
      end
    end
    f.actions
  end

  # ...
end

The configuration (and `permitted_params`) of your `ClassDate` admin panel has nothing to do with the permitted parameters within the `ClassSection` admin panel. Treat them as separate controllers within the app.

Adding the `allow_destroy: true` option to the `has_many` call will add a checkbox to the form to allow you to delete a class time upon form submission.

Problem

I have a nested form in ActiveAdmin for these models (a :class_section has_many :class_dates): ``` class ClassDate < ActiveRecord::Base belongs_to :class_section validates :start_time, :presence => true validates :end_time, :presence => true end ``` and ``` class ClassSection < ActiveRecord::Base belongs_to :class_course has_many :class_dates belongs_to :location accepts_nested_attributes_for :class_dates end ``` Everything seems to be in the right place when I look at the form. However, when I update a class_date, it doesn't save. ``` ActiveAdmin.register ClassSection do permit_params :max_students, :min_students, :info, :class_course_id, :location_id form do |f| f.inputs "Details" do f.input :class_course, member_label: :id_num f.input :min_students, label: "Minunum Students" f.input :max_students, label: "Maxiumum Students" f.input :location end f.inputs do f.input :info, label: "Additional Information" end f.inputs "Dates" do f.has_many :class_dates, heading: false do |cd| cd.input :start_time, :as => :datetime_picker cd.input :end_time, :as => :datetime_picker end end f.actions end index do column :class_course column :location default_actions end filter :class_course filter :location show do |cs| attributes_table do row :class_course do cs.class_course.id_num + " - " + cs.class_course.name end row :location row :min_students, label: "Minunum Students" row :max_students, label: "Maxiumum Students" row :info, label: "Additional Information" end panel "Dates" do attributes_table_for class_section.class_dates do rows :start_time, :end_time end end active_admin_comments end end ``` Here is the ActiveAdmin file for ClassDates: ``` ActiveAdmin.register ClassDate, as: "Dates" do permit_params :start_time, :end_time, :class_section_id belongs_to :class_section end ``` Can you see a reason why it's not saving properly? UPDATE: I added the following code to the AA and it seems to work now: ``` controller do def permitted_params params.permit! end end ``` Let me know if there is a better solution. Thanks. UPDATE 2: There is one lingering problem however. I am unable to delete ClassDates using this form.

Original source