[RUBY] [Rails] Volume that displays favorites and a list of favorites


If you find a product that you think is good for online shopping, have you registered it as a favorite? At that time, if the screen is not updated and you like it or like it, the color of the ♡ mark will change. After that, it would be nice if you could check your favorite products in a list. This time is a memo of the implementation.

Implementation procedure (synchronous edition)

When you click on the completed image, a part of the screen is updated and the number count increases. It also has a delete function. We will also create a page where you can check what you have added to your favorites in a list.

First, as an intermediate table between the items table and the users table Create a likes table.

↓ The columns to be added and the association look like this ↓

items table

Column Type Options

=== Abbreviation ===

likes table #intermediate table

Column Type Options
item_id integer null: false
user_id integer null: false


users table

Column Type Options

=== Abbreviation ===


This completes the DB design Next, create a model. Enter the following command in the terminal

rails g model like

Edit migration file to create table


class CreateLikes < ActiveRecord::Migration[5.2]
  def change
    create_table :likes do |t|
      t.integer :item_id, null: false
      t.integer :user_id, null: false

Rails from db: migrate. Then a model will be generated, so we will write the association.


has_many :likes #add to


has_many :likes #add to


class Like < ApplicationRecord

  belongs_to :item
  belongs_to :user

  validates :user_id, presence: true
  validates :item_id, presence: true
  validates_uniqueness_of :item_id, scope: :user_id

  def self.like_method(item, user)
    Like.find_by(item_id: item.id, user_id: user.id)


self.like_method(item, user) I will set the IF statement here. Set the condition that item_id and user_id are in the like table! Then run the following command to create the controller

rails g controller likes

Once the controller is created successfully ・ View file ·controller ·routing I will set each.


--Omitted ---
resources :items, only: [:new, :create, :edit, :update, :show, :destroy] do
    resources :likes, only: [:create, :destroy]
--Omitted ---
  resources :users, only: [:show] do
    resources :likes, only: [:index]
--Omitted ---

create and destroy are nested in items index nested in users


class LikesController < ApplicationController

  before_action :set_item, only: [:create, :destroy]

  def index
    @items = Item.includes(:item_images).order("created_at DESC")

  def create
    @like = Like.create(item_id: params[:item_id],user_id: current_user.id)
    redirect_to item_path(@item.id)

  def destroy
    @like = Like.find_by(item_id: params[:item_id],user_id: current_user.id)
    redirect_to item_path(@item.id)

  def set_item
    @item = Item.find(params[:item_id])


Since create and destroy do not have a view file, you need to set redirects.


--Omitted ---
      - if user_signed_in? && Like.like_method(@item, current_user)
        .check_btn__like--add{data: {item_id: @item.id}}
          = link_to "/items/#{@item.id}/likes/:id" , method: :DELETE do
            = icon( "fa", "star")
            = @item.likes.length
      - elsif user_signed_in?
        .check_btn__like{data: {item_id: @item.id}}
          = link_to "/items/#{@item.id}/likes", method: :POST do
            = icon( "fa", "star")
            = @item.likes.length
      - else
          = link_to new_user_session_path do
            = icon( "fa", "star")
            = @item.likes.length
--Omitted ---

Click here for the screen when registering as a favorite


Favorite list
      - @items.each do |item|
        - if user_signed_in? && Like.like_method(item, current_user)
              = link_to item_path(item.id) do
                = image_tag item.item_images[0].image.url
              = item.name
                = item.price.to_s
                = "Circle"
                = "(tax included)"
                = link_to "/items/#{item.id}/likes/:id" , method: :DELETE do
                  = icon("fas", "star")

This is what you see in your favorite product list


.like_Wrapper {
  width: 100%;

.like__box {
  margin: 0 auto;
  width: 65%;
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  &__product {
    width: 180px;
    height: 90%;
    margin: 25px 2% 0;
    transition: all .3s ease-in-out;
    .like__image {
      width: 180px;
      height: 140px;
      margin-bottom: 3%;
        width: 100%;
        height: 100%;
        object-fit: cover;
    .like__name {
      font-weight: bold;
      display: flex;
      font-size: 16px;
        font-weight: bold;
      .like__tax {
        font-size: 10px;
        writing-mode: lr-tb;
        width: 30px;
        line-height: 30px;
        margin-left: 2%;
        margin-right: 24%;
      .like__icon {
        i {
          color: orange;
  &__product:hover {
    cursor: pointer;
    transform: scale(1.1, 1.1);

For the time being, CSS I think that it can be implemented in a synchronized state with the implementation so far! So far, if you implement asynchronous communication using Ajax, it will be richer, so I wish I could write that ... It will be later ...

Image from Gyazo

Image from Gyazo


https://techtechmedia.com/favorite-function-rails/#i https://qiita.com/naberina/items/c6b5c8d7756cb882fb20 https://qiita.com/hisamura333/items/e3ea6ae549eb09b7efb9 https://qiita.com/shh-nkmr/items/48fe53282253d682ecb0

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