ActiveAdmin Model Stubs - Form/Service objects

active_admin_model_stubs.rb

# Created by essentially answering all of the methods that were called on a PORO.  Adjust as you see fit
module ActiveAdminModelStubs
  extend ActiveSupport::Concern

  # duck punch - ActiveAdmin uses these for index page.  We don't have an index.
  module ClassMethods

    # Columns makes no sense in the context of a form.
    def columns(*)
      []
    end

    def reorder(*)
      self
    end

    def ransack(*)
      self
    end

    def result(*)
      self
    end

    def page(*)
      self
    end

    def per(*)
      self
    end

    def except(*)
      self
    end

    def group_values(*)
      self
    end

    def count(*)
      self
    end

    def num_pages(*)
      1
    end

    def total_pages(*)
      1
    end

    def current_page(*)
      1
    end

    def limit_value(*)
      false
    end

    def total_count(*)
      1
    end
  end
end

some_process_form.rb

module SomeNamespace
  class SomeProcessForm
    include ActiveAdminModelStubs
    include ActiveModel::Model

    attr_accessor :attr_1, :attr_2

     # We're just overriding this since we're overriding the display completely
    def self.column_names
      []
    end

    def perform!
      SomeServiceClass.new(attr_1: attr_1, attr_2: attr_2, opt_a: :some_static_option).perform!
    end

  end
end

some_process_form_admin.rb

ActiveAdmin.register SomeNamespace::SomeProcessForm do
  menu label: 'Some Process', parent: 'Some Namespace'
  permit_params :attr_1, :attr_2 # Make sure to update these to match the attributes as you see fit on your form object!

  config.batch_actions = false
  actions :all, except: [:new, :destroy, :edit]

  controller do

    def show
      # A lot of times we redirect on show to something more relevant, like an instance of what the form manipulates
    end

    private

    def collection
      # Return a list of objects to show in the index
      SomeModel.all.page(params[:page]).per(30) # Make sure to add the pagination methods!
    end
  end

  index download_links: false do
    column :attr_1
    column :attr_2
    column :some_other_derived_value do |obj|
      # do something with the object
    end
  end
end