ページ遷移にこだわりたかった

プログラミングスクールでDeviseのgemを用いたユーザーログイン機能を経験していたのですが、
・入力した情報を確認して修正することができない
・データ登録したらすぐトップページに戻ってしまう（登録完了しましたのアナウンスがない）
・１画面に表示される入力項目が多すぎる
といった機能に対する納得のいかなさがあったので、

自主的なアプリ制作では、
・記入項目の確認画面を実装する
・記入項目の登録完了画面を実装する
・入力画面を複数のページで遷移するように設定する
という点にこだわって作ろうと思いました。

要は、
ウィザード機能＋登録確認完了画面を両方実装するというのが目標でした。

機能実装にあたり参考にした記事

「Railsウィザード形式フォームで新規登録〜Devise+session〜」
https://qiita.com/ATORA1992/items/40fc543742a6df5a17c1
こちらの記事を参考にDeviseとsessionを組み合わせた実装のやり方を採用しました。

「ウィザード形式の登録フォームでバリデーション」
https://qiita.com/ATORA1992/items/c073620be3469bfa1f54
バリデーションももちろんかけちゃう。

「【Rails】deviseの会員登録に確認画面と完了画面を加える。」
https://qiita.com/MasaoSasaki/items/9e92d8f675a5eed5a916
確認画面と完了画面の実装はこちらを参照に。

…他にもいろいろ見てたのですがリンク先を記録し忘れるという大失態。。。

実際に書いたコード

config/routes.rb

Rails.application.routes.draw do

  resource :informations do
    collection do
      get 'step1'
      get 'step2'
      get 'step3' # ここで、入力の全てが終了する
      post 'confirm' # 確認用ページ
      get 'done' # 登録完了後のページ
    end
  end
  
  root to: 'informations#index'

end

controllers/application_controller.rb

class ApplicationController < ActionController::Base
  before_action :configure_permitted_parameters, if: :devise_controller?

  private

  def configure_permitted_parameters
    devise_parameter_sanitizer.permit(:sign_up, keys: [:firstname, :lastname, :firstname_kana, :lastname_kana, :sex, :birth_day, :phone_number, :image, :postal_code, :prefecture_id, :city, :building, :highschool, :h_admission, :h_graduate, :univercity, :u_admission, :u_graduate, :job_experience, :qualfication_1, :qualfication_2, :qualfication_3, :q_year_1, :q_year_2, :q_year_3, :station, :spouse])
  end
end

controllers/informations_controller.rb

class InformationsController < ApplicationController
  before_action :save_to_session, only: :step2
  before_action :save_to_session_2, only: :step3
  before_action :save_to_session_3, only: :confirm

  def index
    @users = User.all
  end

  def step1
    @user = User.new
    # 新規インスタンス作成
  end

  def step2
    @user = User.new
    # 新規インスタンス作成
  end

  def step3
    @user = User.new
    # 新規インスタンス作成
  end

  def confirm
    @user.image.save if @user.image.attached?
    @user = User.new(
      firstname: session[:firstname],
      lastname: session[:lastname],
      firstname_kana: session[:firstname_kana],
      lastname_kana: session[:lastname_kana],
      email: session[:email],
      sex: session[:sex],
      password: session[:password],
      password_confirmation: session[:password_confirmation],
      birth_day: session[:birth_day],
      phone_number: session[:phone_number],
      postal_code: session[:postal_code],
      prefecture_id: session[:prefecture_id],
      city: session[:city],
      building: session[:building],
      highschool: user_params[:highschool],
      h_admission: user_params[:h_admission],
      h_graduate: user_params[:h_graduate],
      univercity: user_params[:univercity],
      u_admission: user_params[:u_admission],
      u_graduate: user_params[:u_graduate],
      job_experience: user_params[:job_experience],
      qualification_1: user_params[:qualification_1],
      q_year_1: user_params[:q_year_1],
      qualification_2: user_params[:qualification_2],
      q_year_2: user_params[:q_year_2],
      qualification_3: user_params[:qualification_3],
      q_year_3: user_params[:q_year_3],
      station: user_params[:station],
      spouse: user_params[:spouse]
    )
    if @user.valid?
      render 'confirm'
    else
      render '/informations/step3'
    end
  end

  def create
    @user = User.new(
      firstname: session[:firstname],
      lastname: session[:lastname],
      firstname_kana: session[:firstname_kana],
      lastname_kana: session[:lastname_kana],
      email: session[:email],
      sex: session[:sex],
      password: session[:password],
      password_confirmation: session[:password_confirmation],
      birth_day: session[:birth_day],
      phone_number: session[:phone_number],
      postal_code: session[:postal_code],
      prefecture_id: session[:prefecture_id],
      city: session[:city],
      building: session[:building],
      highschool: session[:highschool],
      h_admission: session[:h_admission],
      h_graduate: session[:h_graduate],
      univercity: session[:univercity],
      u_admission: session[:u_admission],
      u_graduate: session[:u_graduate],
      job_experience: session[:job_experience],
      qualification_1: session[:qualification_1],
      qualification_2: session[:qualification_2],
      qualification_3: session[:qualification_3],
      q_year_1: session[:q_year_1],
      q_year_2: session[:q_year_2],
      q_year_3: session[:q_year_3],
      station: session[:station],
      spouse: session[:spouse]
    )

    render step1_informations_path and return if params[:back]

    if @user.save
      session[:id] = @user.id
      redirect_to done_informations_path
    else
      render '/informations/step1'
    end
  end

  def done
    sign_in User.find(session[:id]) unless user_signed_in?
    session[:firstname].clear
    session[:lastname].clear
    session[:firstname_kana].clear
    session[:lastname_kana].clear
    session[:email].clear
    session[:sex].clear
    session[:password].clear
    session[:password_confirmation].clear
    session[:birth_day].clear
    session[:phone_number].clear
    session[:postal_code].clear
    session[:prefecture_id].clear
    session[:city].clear
    session[:building].clear
    session[:highschool].clear
    session[:h_admission].clear
    session[:h_graduate].clear
    session[:univercity].clear
    session[:u_admission].clear
    session[:u_graduate].clear
    session[:job_experience].clear
    session[:qualification_1].clear
    session[:qualification_2].clear
    session[:qualification_3].clear
    session[:q_year_1].clear
    session[:q_year_2].clear
    session[:q_year_3].clear
    session[:station].clear
    session[:spouse].clear
  end

  def save_to_session
    session[:firstname] = user_params[:firstname]
    session[:lastname] = user_params[:lastname]
    session[:firstname_kana] = user_params[:firstname_kana]
    session[:lastname_kana] = user_params[:lastname_kana]
    session[:email] = user_params[:email]
    session[:sex] = user_params[:sex]
    session[:password] = user_params[:password]
    session[:password_confirmation] = user_params[:password_confirmation]
    session[:birth_day] = Date.new(params[:user]['birth_day(1i)']&.to_i, params[:user]['birth_day(2i)']&.to_i, params[:user]['birth_day(3i)']&.to_i)
    session[:phone_number] = user_params[:phone_number]
    # バリデーションをかけるため、仮でインスタンスに入力値を入れる

    @user = User.new(
      firstname: session[:firstname],
      lastname: session[:lastname],
      firstname_kana: session[:firstname_kana],
      lastname_kana: session[:lastname_kana],
      email: session[:email],
      sex: session[:sex],
      password: session[:password],
      password_confirmation: session[:password_confirmation],
      birth_day: session[:birth_day],
      phone_number: session[:phone_number],
      postal_code: '1234567',
      prefecture_id: '1',
      city: 'shinjyku',
      building: '',
      highschool: 'tokyo',
      h_admission: '2000',
      h_graduate: '',
      univercity: '',
      u_admission: '',
      u_graduate: '',
      job_experience: 'xxx',
      qualification_1: 'aaa',
      qualification_2: 'bbb',
      qualification_3: 'ccc',
      q_year_1: '1',
      q_year_2: '2',
      q_year_3: '3',
      station: 'shinjyku',
      spouse: 'あり'
    )
    # binding.pry
    # インスタンスにバリデーションをかけ、通らなければ1step目のページを再度表示する
    render '/informations/step1' unless @user.valid?(:save_to_session)
  end

  def save_to_session_2
    session[:postal_code] = user_params[:postal_code]
    session[:prefecture_id] = user_params[:prefecture_id]
    session[:city] = user_params[:city]
    session[:building] = user_params[:building]

    @user = User.new(
      firstname: session[:firstname],
      lastname: session[:lastname],
      firstname_kana: session[:firstname_kana],
      lastname_kana: session[:lastname_kana],
      email: session[:email],
      sex: session[:sex],
      password: session[:password],
      password_confirmation: session[:password_confirmation],
      birth_day: session[:birth_day],
      phone_number: session[:phone_number],
      postal_code: session[:postal_code],
      prefecture_id: session[:prefecture_id],
      city: session[:city],
      building: session[:building],
      highschool: 'tokyo',
      h_admission: '2000',
      h_graduate: '',
      univercity: '',
      u_admission: '',
      u_graduate: '',
      job_experience: 'xxx',
      qualification_1: 'aaa',
      qualification_2: 'bbb',
      qualification_3: 'ccc',
      q_year_1: '1',
      q_year_2: '2',
      q_year_3: '3',
      station: 'shinjyku',
      spouse: 'あり'
    )
    render '/informations/step2' unless @user.valid?(:save_to_session_2)
  end

  def save_to_session_3
    session[:highschool] = user_params[:highschool]
    session[:h_admission] = user_params[:h_admission]
    session[:h_graduate] = user_params[:h_graduate]
    session[:univercity] = user_params[:univercity]
    session[:u_admission] = user_params[:u_admission]
    session[:u_graduate] = user_params[:u_graduate]
    session[:job_experience] = user_params[:job_experience]
    session[:qualification_1] = user_params[:qualification_1]
    session[:q_year_1] = user_params[:q_year_1]
    session[:qualification_2] = user_params[:qualification_2]
    session[:q_year_2] = user_params[:q_year_2]
    session[:qualification_3] = user_params[:qualification_3]
    session[:q_year_3] = user_params[:q_year_3]
    session[:station] = user_params[:station]
    session[:spouse] = user_params[:spouse]

    @user = User.new(
      firstname: session[:firstname],
      lastname: session[:lastname],
      firstname_kana: session[:firstname_kana],
      lastname_kana: session[:lastname_kana],
      email: session[:email],
      sex: session[:sex],
      password: session[:password],
      password_confirmation: session[:password_confirmation],
      birth_day: session[:birth_day],
      phone_number: session[:phone_number],
      postal_code: session[:postal_code],
      prefecture_id: session[:prefecture_id],
      city: session[:city],
      building: session[:building],
      highschool: session[:highschool],
      h_admission: session[:h_admission],
      h_graduate: session[:h_graduate],
      univercity: session[:univercity],
      u_admission: session[:u_admission],
      u_graduate: session[:u_graduate],
      job_experience: session[:job_experience],
      qualification_1: session[:qualification_1],
      qualification_2: session[:qualification_2],
      qualification_3: session[:qualification_3],
      q_year_1: session[:q_year_1],
      q_year_2: session[:q_year_2],
      q_year_3: session[:q_year_3],
      station: session[:station],
      spouse: session[:spouse]
    )
    render '/informations/step3' unless @user.valid?(:save_to_session_3)
  end

  private

  # 許可するキーを設定します
  def user_params
    params.require(:user).permit(
      :image,
      :firstname,
      :lastname,
      :firstname_kana,
      :lastname_kana,
      :email,
      :sex,
      :password,
      :password_confirmation,
      :birth_day,
      :phone_number,
      :postal_code,
      :prefecture_id,
      :city,
      :building,
      :highschool,
      :h_admission,
      :h_graduate,
      :univercity,
      :u_admission,
      :u_graduate,
      :job_experience,
      :qualification_1,
      :qualification_2,
      :qualification_3,
      :q_year_1,
      :q_year_2,
      :q_year_3,
      :station,
      :spouse
    )
  end
end

これでなんとかデータ入力を形にすることができました！