The story of the first Rails app refactored with a self-made helper

Introduction

I've been writing applications with Ruby on Rails I was curious about it.

This guy that comes with every time you create a controller 〇〇_helper.rb What is this file used for ... Since it says helper, is it related to helper methods ... ??

At this time, I "It must be a convenient file because it is created at the same time." I searched Qiita for commentary articles as I was interested.

Conclusion

It looks like a file that describes your own helper method. (Self-made helper == custom helper) Since the helper method has only used the things provided by Gem until today, I intuitively thought that this would be useful.

I tried using it immediately

I will refer to other people's Qiita articles This time I used it for code refactoring of my personally developed app. The refactoring content in the controller is the content of this article.

environment

Rails 5.2.3 Ruby 2.5.1

How to use

First, let's look at the controller that refactors.

users_controller.rb

class UsersController < ApplicationController

~abridgement~

  private
  def set_user
    @user = User.find(params[:id])
  end

  def check_user
    redirect_to new_user_registration_path, alert: 'Please log in or register' unless current_user.id == @user.id
  end
end

Because the less than unless in the method called check_user is not cool Create a helper method and refactor it.

helpers/users_helper.rb

module UsersHelper

  def current_user?(user)
    current_user.id == user.id
  end

end

I created a helper method called current_user ?. This method name and content seems to be quite standard.
Directly under the directory called helpers There is also a file called application_helper.rb It's like a file that manages helper methods that you apply to multiple controllers and views.

• Unused this time
  Let's apply the helper method created at once in the controller.

users_controller.rb

class UsersController < ApplicationController
  include UsersHelper

~abridgement~

  private
  def set_user
    @user = User.find(params[:id])
  end

  def check_user
    redirect_to new_user_registration_path, alert: 'Please log in or register' if !current_user?(@user)
  end
end

Description

When using the helper file's own helper in the controller It seems that it is necessary to read with include as in the second line.

• The writer corresponds to the controller name and the helper file name, so I'll do it without permission. I thought that Rails-specific processing would be included, but it seems that a description is necessary.
  The refactoring content Pass @user defined by set_user as an argument I used the current_user? Method I created earlier.

Also, the description of unless has been changed to the description of if! ~. This made the code a little cleaner.

Refactor posts_controller with similar content.

posts_controller.rb

class PostsController < ApplicationController
  

  def edit
    redirect_to new_user_registration_path, alert: 'Please log in' unless current_user.id == @a_post.user_id
  end

  def destroy
    redirect_to new_user_registration_path, alert: 'Please log in' unless current_user.id == @a_post.user_id
    if @a_post.destroy
      redirect_to root_path, notice: 'Deleted post'
    else
      render :show, notice: 'The post could not be deleted'
    end
  end


  private

  def set_post
    @a_post = Post.find(params[:id])
  end
end

Here too, we will modify the description below unless.

First, create a helper method.

helpers/posts_helper.rb

module PostsHelper

  def current_user_post?(a_post)
    current_user.id == a_post.user_id
  end

end

We will apply this to the controller.

posts_controller.rb

class PostsController < ApplicationController
  include PostsHelper

  def edit
    redirect_to new_user_registration_path, alert: 'Please log in' if !current_user_post?(@a_post)
  end

  def destroy
    redirect_to new_user_registration_path, alert: 'Please log in' if !current_user_post?(@a_post)
    if @a_post.destroy
      redirect_to root_path, notice: 'Deleted post'
    else
      render :show, notice: 'The post could not be deleted'
    end
  end

  private

  def set_post
    @a_post = Post.find(params[:id])
  end
end

This is also done after loading the helper and refactoring.

Finally

This time I wrote an article focusing on the controller, but it can be used not only for self-made helpers but also for views. Also, when using it for a view, unlike the controller, it seems that there is no need to describe reading. I'll also refactor the view file code after this.

If you find any deficiencies, please let us know in the comments.

Reference article

--Helper loading and priority in Rails 5.0 -Summary of Rails helper methods (frequently used)