Auto reloading Rails Admin

Shifting from Rails 6 to Rails 7 has made us have to make some changes to how we structure some of our Rails apps. One of these changes was where we located our Rails Admin configuration.

Previously we had located our Rails Admin config in their own files within app/models/concerns/ and required them within each referenced model. Changes to how Rails loaded in Rails Admin made us change to having our config situated entirely within config/initializers/rails_admin.rb this meant we could set up auto reloading. You can only use auto reloading if all of your config sits in rails_admin.rb.

The below code is borrowed heavily from the Rails Admin documentation. I have written this article as I was slightly confused by the documentation.

First off you’ll want to add this to your Rails Admin config file:

rails_admin.rb

RailsAdmin.config do |config|
  config.parent_controller = ApplicationController.to_s
  # other code...
end

Then in your application controller you’ll want to add this:

application_controller.rb

class ApplicationController < ActionController::Base
  protect_from_forgery

  before_action :reload_rails_admin, if: :rails_admin_path?

  # Your other application controller code...

  private

  def reload_rails_admin
    # List all the models you want to auto reload
    models = %W(User
                Article
                Comment
                OtherModel
                AnotherModel)

    models.each do |m|
      RailsAdmin::Config.reset_model(m)
    end

    RailsAdmin::Config::Actions.reset

    load(Rails.root.join('config/initializers/rails_admin.rb'))
  end

  def rails_admin_path?
    controller_path =~ /rails_admin/ && Rails.env.development?
  end
end

This has been great as it’s meant we haven’t had to constantly restart the server when making small changes to the admin, which can be pretty frustrating when you’re trying to maintain focus.