activeadmin strong parameters extension

strong_admin.rb

module StrongAdmin

  extend ActiveSupport::Concern

  def initialize
    @instance_name = active_admin_config.resource_class.name.underscore.to_sym
    @klass = active_admin_config.resource_class

    super
  end

  def create
    resource_obj = instance_variable_set("@#{@instance_name}", @klass.new(params[@instance_name].permit!))

    if resource_obj.save
      redirect_to send("admin_#{@instance_name}_path", resource_obj), notice: "Created #{@instance_name}."
    else
      render :new
    end
  end

  def update
    resource_obj = instance_variable_set("@#{@instance_name}", @klass.find(params[:id]))

    if resource_obj.update_attributes(params[@instance_name].permit!)
      redirect_to send("admin_#{@instance_name}_path", resource_obj), notice: "Updated #{@instance_name}."
    else
      render :edit
    end
  end

end