How to show name of user who wrote comment (Rails)? - ruby-on-rails

Question

In my rails app I have users(authors),posts(articles),comments. If registered user write comment to article, I want to show his name beside his comment, if he isn't registered user I want to show "Anonymous" beside his comment. How can I do this?
comment model:
class Comment < ActiveRecord::Base
attr_accessible :post_id, :text
belongs_to :post
belongs_to :user
end
user model:
class User < ActiveRecord::Base
# Include default devise modules. Others available are:
# :token_authenticatable, :confirmable,
# :lockable, :timeoutable and :omniauthable
has_many :posts, :dependent => :destroy
has_many :comments, :dependent => :destroy
validates :fullname, :presence => true, :uniqueness => true
validates :password, :presence => true
validates :email, :presence => true, :uniqueness => true
devise :database_authenticatable, :registerable,
:recoverable, :rememberable, :trackable, :validatable
attr_accessible :email, :password, :password_confirmation, :fullname
end
post model:
class Post < ActiveRecord::Base
attr_accessible :text, :title, :tag_list
acts_as_taggable
validates :user_id, :presence => true
validates :title, :presence => true
validates :text, :presence => true
belongs_to :user
has_many :comments
end
view file (show.html.erb)
<h1><%= #post.title %></h1>
<p>
Created: <%= #post.created_at.strftime("%Y/%m/%d")%> by
<%= link_to #post.user.fullname, user_posts_path(#post.user) %>
</p>
<p><%=simple_format #post.text %></p>
<p>
Tags: <%= raw #post.tag_list.map { |t| link_to t, tag_path(t) }.join(', ') %>
</p>
<h2>Comments</h2>
<% #post.comments.each do |comment| %>
<p><%= comment.created_at.strftime("%Y/%m/%d") %>
by <%= HERE I NEED ADD SOMETHING%></p>
<p><%= comment.text %></p>
<p><%= link_to "Delete comment", [#post, comment], :method => :delete,
:confirm =>"Are you sure?"%></p>
<% end %>
<%= form_for [#post, #post.comments.build] do |f| %>
<p><%= f.text_area :text %></p>
<p><%= f.submit "Post comment" %></p>
<% end %>
<% if user_signed_in?%>
<p>
<%= link_to "Back", posts_path %>
<%= link_to "Edit", edit_post_path(#post) %>
<%= link_to "Delete", #post, :method => :delete, :confirm => "Are you sure?"%>
</p>
<% end%>

Answer 1

You can do this by calling the user method on the comment, and then name on that:
<%= comment.user.name %>
You can also define a to_s method in the User model:
def to_s
name
end
Which would mean you could get away with doing just this in the view:
<%= comment.user %>
If you're loading a whole bunch of comments, then I would recommend loading them this way:
#comments = Comment.includes(:user)
If you don't have that includes(:user) there, then Rails will issue a new query for every single comment to find that comment's user. Doing it this way makes Rails load all the users for all the comments upfront in just one query.

Answer 2

I think you want to create two assocations pointing to the same table:
class CreatePostss < ActiveRecord::Migration
def change
create_table :posts do |t|
t.text :text
t.references :user, index: true, foreign_key: true
t.references :author, index: true, foreign_key: { to_table: :users }
t.timestamps null: false
end
end
end
Here user_id references the target user of the post and author_id references the user writing the post. Both reference users.id.
Then create two belongs_to associations in your post model:
class Post < ApplicationRecord
belongs_to :user
belongs_to :author,
class_name: 'User',
inverse_of: :authored_posts
end
And two has_many associations in your User model:
class User < ApplicationRecord
# posts about this user
has_many :posts
# postss written by this user
has_many :authored_posts,
class_name: 'Post',
foreign_key: :author_id,
inverse_of: :author
end
Here is the controller
class PostsController < ApplicationController
before_action :set_user, only: [:new, :create]
# ...
def new
#post = #user.posts.new
end
def create
#post = #user.posts.new(post_params) do |c|
c.author = current_user
end
if #post.save
redirect_to doctor_path(id: #user.id)
else
render :new
end
end
private
def set_user
#user = User.find(params[:id])
end
# ...
end
To display posts you would do:
<% #user.posts.each do |post| %>
<div class="post">
<div class="body">
<%= post.body %>
</div>
<p class="author"><%= post.author.email %></p>
</div>
<% end %>