Learning Rails 24 Decorators Pattern

bash

vi app/models/user.rb

Add this line

user.rb

def past_5_days?
  created_at >= 5.days.ago
end

current user.rb

user.rb

class User < ActiveRecord::Base
  has_many :reviews
  has_many :user_items
  has_many :items, through: :user_items
 
  validates :name,
            presence: true,
            length: {minimum: 3}
 
  def past_5_days?
    created_at >= 5.days.ago
  end
end

bash

vi app/views/users/index.html.erb

Add this line

index.html.erb

<% if user.past_5_days? %>
<% end %>

current index.html.erb

index.html.erb

<h1>Users</h1>
 
<ul>
  <% @users.each do |user| %>
    <li>
      <% if user.past_5_days? %>
        <%= link_to user.name, user_path(user.id) %>:<%= user.approved%>;
        <%= link_to 'edit', edit_user_path(user.id) %>;
        <%= link_to 'delete', user_path(user.id), method: :delete, data: {confirm: "Are you sure?"} %>
        <%= link_to 'suspend', suspend_user_path(user.id), data: {confirm: "suspend?"} %>
        <%= link_to 'permit', permit_user_path(user.id), data: {confirm: "permit?"} %>
      <% end %>
    </li>
  <% end %>
</ul>
 
<p><%= link_to "Add New", new_user_path %></p>

past_5_days method is used only view file.
It it right?

We will refactor it

bash

mkdir app/decorators

bash

vi app/decorators/user_decorator.rb

user_decorator.rb

class UserDecorator
  attr_reader :user
 
  def initialize(user)
    @user = user
  end
 
  def past_5_days?
    user.created_at >= 5.days.ago
  end
end

Delete past_5days?
current user.rb

user.rb

class User < ActiveRecord::Base
  has_many :reviews
  has_many :user_items
  has_many :items, through: :user_items
 
  validates :name,
            presence: true,
            length: {minimum: 3}
end

bash

vi app/views/users/index.html.erb

index.html.erb

<% if UserDecorator.new(user).past_5_days? %>
<% end %>

current index.html.erb

index.html.erb

<h1>Users</h1>
 
<ul>
  <% @users.each do |user| %>
    <li>
      <% if UserDecorator.new(user).past_5_days? %>
        <%= link_to user.name, user_path(user.id) %>:<%= user.approved %>;
        <%= link_to 'edit', edit_user_path(user.id) %>;
        <%= link_to 'delete', user_path(user.id), method: :delete, data: {confirm: "Are you sure?"} %>
        <%= link_to 'suspend', suspend_user_path(user.id), data: {confirm: "suspend?"} %>
        <%= link_to 'permit', permit_user_path(user.id), data: {confirm: "permit?"} %>
      <% end %>
    </li>
  <% end %>
</ul>
 
<p><%= link_to "Add New", new_user_path %></p>

We will change show method in users_controller

bash

vi app/controllers/users_controller.rb

users_controller.rb

require 'user_decorator'

users_controller.rb

def show
  @user_decorator = UserDecorator.new(@user)
  @items = Item.all.pluck(:name, :id)
end

bash

vi app/views/users/show.html.erb

show.html.erb

<% if @user_decorator.past_5_days? %>
  <%= @user_decorator.name %>:<%= @user_decorator.approved %>
<% end %>

Add this line

user_decorator.rb

def method_missing(method_name, *args, &block)
  user.send(method_name, *args, &block)
end

bash

ctrl + c

bash

rails c

We need to refactor Decorator

console

rails c

console

require '/srv/www/learning/app/decorators/user_decorator'

console

user_decorator = UserDecorator.new User.first

console

user_decorator.respond_to?(:name)

result is false. However result should be true.

bash

vi app/decorators/user_decorator.rb

user_decorator.rb

def respond_to_missing?(method_name, include_private = false)
  user.respond_to?(method_name, include_private) || super
end

console

user_decorator.respond_to?(:name)

result is true now