[RUBY] [Rails] Show avatars in posts using Active Storage

Thing you want to do

I want to display avatars and user names in Posts # index (hereinafter referred to as timeline)

Premise

Introducing devise Introduced Active Storage Add avatar to users model

manner

Added has_one_attached and user instance methods for: avatar to the posts model

post.rb

class Post < ApplicationRecord
  validates :content, {presence: true, length: {maximum: 140}}
  validates :user_id, {presence: true}
    
  has_one_attached :avatar
  
  def user
    return User.find_by(id: self.user_id)
  end
end

Add .user to view

Ruby:index.html.erb

    <% @posts.each do |post| %>
    <div class="posts-index-item mb-20">
      <div class="posts-index-user">
        <!--avatar-->
        <div class="posts-index-img d-inline">
          <% if post.user.avatar.attached? %>
            <%= image_tag post.user.avatar, class: "avatar-index rounded-circle mx-auto" %>
          <% else %>
            <img class="avatar-index rounded-circle mx-auto" src="<%= "/images/default_user.png " %>" alt="Userimage">
          <% end %>
        </div>
        <!--username-->
        <div class="posts-index-username d-inline">
          <%= link_to post.user.username, users_show_path %>
        </div>
      </div>
      <!--content-->
      <%= link_to(post.content, "/posts/#{post.id}") %>
    </div>
  <% end %>

result

Summary

User model can be handled even in posts # index where params cannot be used by user method. ⇒ You can handle : avatar linked to the User model by post.user.avatar