[RAILS] User evaluation using the like function

Introduction

In the production of Oriap, I added a purchase function so that the details of the product can only be seen after purchase. Therefore, it is necessary to have a function that can be a decisive factor in the purchase of the buying side user by making it possible to see the evaluation of the selling side user. This time, we implemented it so as to give a user evaluation (** Good ** or ** Bad **) by using the like function for the product.

Conditions that have been completed by the time of implementation

1. The devise gem has already been introduced and the contents are also described.
2. The product is defined as idea, and the idea model and idea controller have been created and the contents are also described.
3. User and idea routing settings, associations, etc. have been completed.

1. Implementation of like function (Good evaluation)

** 1. To implement the Like function, first create a Like table (intermediate table) to store UserID and IdeaID. ** **

Terminal

$ rails g model like post:references user:references
$ rails db:migrate

** 2. Associate user model, idea model, and like model respectively. ** **

user model

class User < ApplicationRecord
#Omission
  has_many :likes
end

idea model

class Idea < ApplicationRecord
#Omission
  has_many :likes
end

like model

class Like < ApplicationRecord
  belongs_to :user
  belongs_to :idea
end

** 3. Create a like controller.
Since we only save likes this time, define only the create action in the like controller. ** **

Terminal

$ rails g controller likes

like controller

class LikesController < ApplicationController
  def create
    Like.create(user_id: current_user.id,idea_id: params[:idea_id])
    redirect_to root_path
  end
end

** 4. Set the routing.
like is related to idea, so nest it in idea and set it. ** **

routes.rb

Rails.application.routes.draw do
#Omission
  resources :ideas,except: :index do
    resources :likes, only: :create
    #Omission
  end
#Omission
end

** 5. Describe so that the like button (Good button) is displayed in the view file. ** **

html:views/ideas/show.html.erb

<!--Omission-->
<div>
　<%= button_to 'Good', idea_likes_path(@idea), class:'good-btn' %>
</div>
<!--Omission-->

2. Implementation of like function (Bad evaluation)

Replace ** like ** in the implementation of the like function (Good evaluation) with ** dislike **, and repeat the same process.

I was able to additionally display the Good button and Bad button as shown in the image below on the screen after purchasing the product.

3. Display of user evaluation (Good Bad)

Since the purpose of this time is to implement a function to understand the evaluation of the user who sells the product, the ** Good or Bad total ** attached to all the products of that user is acquired and displayed. There is a need to.
Since we want to display the user evaluation on the user page, we will describe it in the show action.

** 1. Get the idea associated with User with User controller. ** **

User controller

class UsersController < ApplicationController
  def show
    @user = User.find(params[:id])
    @user_ideas= @user.ideas
  end
end

** 2. Write the code to calculate the sum of the variable @likes_count and the variable @dislikes_count using the each method. ** **

User controller

class UsersController < ApplicationController
def show
    @user = User.find(params[:id])
    @user_ideas= @user.ideas
    #Calculate the total of Good
    @likes_count = 0
    @user_ideas.each do |idea|
      @likes_count += idea.likes.count
    end

　　#Calculate the total of Bad
    @dislikes_count = 0
    @user_ideas.each do |idea|
      @dislikes_count += idea.dislikes.count
    end
  end
end

** 3. Describe @likes_count (Good evaluation) and @dislikes_count (Bad evaluation) in views/users/show.html.erb and display them. ** **

html:views/users/show.html.erb

<div class="good-button"><%= @likes_count%></div>　   <!--Good rating-->
<div class="bad-button2"><%= @dislikes_count%></div>  <!--Bad evaluation-->

4. Implementation completed

It is now displayed on the user page as shown in the image below. The number of Goods and Bads is displayed, and you can see the user's rating.

5. Finally

In implementing this time, I was able to learn the intermediate table etc. again, so I think it was a good review.

6. Reference article

I implemented it referring to the following article. Thank you very much. https://qiita.com/nojinoji/items/2c66499848d882c31ffa https://freecamp.life/rails-favorite/ https://yumanoblog.com/rails-likes/