Multiform setup controller

new.html.erb

<%= render "#{@step}_form" %>

setups_controller.rb

class SetupController < ApplicationController
  before_action :redirect_if_complete
  before_action :set_steps

  def create
    if params[:back_button]
      previous_step
      render 'new' and return
    end

    @setup = Setup.new(@step, strong_params)
    @form = @setup.execute_step
    next_step if @form.valid?

    render 'new'
  end

  private
    def strong_params
      params.permit(
        :establishment_name,
        agencies_form: {
          agencies_attributes: [ :id, :name, :_destroy ]
        },
        categories_form: {
          categories_attributes: [ :id, :name, :color, children_attributes: [ :id, :name, :color ] ]
        },
        user_groups_form: {
          user_groups_attributes: [ :id, :name, :_destroy ]
        },
        users_form: {
          users_attributes: [ :id, :name, :_destroy ]
        }
      )
    end

    def redirect_if_complete
      redirect_to dash_path if Setting.get(:setup_complete)
    end

    def set_steps
      @step_number = session[:setup_step] || 1
      @step = Setup::STEPS[@step_number]
      @previous_step = Setup::STEPS[@step_number - 1] unless @step_number <= 1
      @next_step = Setup::STEPS[@step_number + 1] unless @step_number > Setup::STEPS.keys.max
    end

    def next_step
      session[:setup_step] = @step_number + 1
      set_steps
      @form = nil
    end

    def previous_step
      session[:setup_step] = @step_number - 1
      set_steps
    end
end