Question

I created a Micropost model that have the following attributes:

<Micropost id: 1, content: "test", user_id: 1, created_at: "2012-01-25 15:34:30", updated_at: "2012-01-29 11:07:53", title: "asdasdad">

an User model with the following attributes:

<User id: 1, email: "[e-mail]", username: nil, etc...>

and a Comment model with the following attributes:

<Comment id: 1, content: "sdf", micropost_id: 1, user_id: nil, created_at: "2012-01-29 11:10:42", updated_at: "2012-01-29 11:10:42">

So far, I’ve only accomplished this:

• Display the username of the author of a micropost

• Display the ID of the authors of the microposts’ comments

  <h2>Micropost Index</h2>
  <% @microposts.each do |micropost| %>
  
  <%= micropost.title %></td>
  <%= micropost.content %></td>
  <%= link_to 'Show', micropost %></td>
  <%= link_to 'Edit', edit_micropost_path(micropost) %></td>
  <%= link_to 'Destroy', micropost, confirm: 'Are you sure?', method: :delete %>     
  

  <h2>Comments</h2>
  
  <% @micropost.comments.each do |comment| %>
    <p>
      <b>Comment:</b>
      <%= comment.content %>
    </p>
    <p>
      <b>Commenter</b>
      <%= comment.user_id %>
    </p>
  <% end %>
  

• I don’t know how to create a link to the authors profile (e.g. mysite.com/users/1).

• I don’t how to retrieve the name of the author of a comment and the link to his/her profile

EDIT:

Models:

user.rb:

class User < ActiveRecord::Base
  # Include default devise modules. Others available are:
  # :token_authenticatable, :encryptable, :confirmable, :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable,
         :omniauthable

  # Setup accessible (or protected) attributes for your model
  attr_accessible :email, :password, :password_confirmation, :remember_me, :username

  has_many :microposts
  has_many :comments

  def self.find_for_facebook_oauth(access_token, signed_in_resource=nil)
    data = access_token.extra.raw_info
    if user = User.where(:email => data.email).first
      user
    else # Create a user with a stub password. 
      User.create!(:email => data.email, :password => Devise.friendly_token[0,20]) 
    end
  end
end

micropost.rb:

class Micropost < ActiveRecord::Base
  attr_accessible :title, :content

  belongs_to :user
  has_many :comments
end

comment.rb:

class Comment < ActiveRecord::Base
  attr_accessible :content, :user_id

  belongs_to :micropost
  belongs_to :user
end

Micropost controller:

controllers/microposts.rb

  def show
    @micropost = Micropost.find(params[:id])
  end

  def new
    @micropost = Micropost.new
  end

  def create
    @user = current_user
    @micropost = @user.microposts.new(params[:micropost])
    @micropost.save
    redirect_to @micropost
  end

Any suggestions to accomplish this?

Answer 1

To make a link to the user you can use

<%= link_to comment.user.username, comment.user %>

In general part of the “Rails Magic” is, that you if you set up an association correctly, that you can access the related objects through the dot notation. That means, you don’t need to say comment.user_id but instead go directly for the associated user object, e.g. comment.user.username or comment.user.email … you get the idea 🙂

In order to to this you should have set up your models like this:

class User < ActiveRecord::Base
  validates_presence_of :username #username should obviously not allow nil values
  has_many :microposts
  has_many :comments
end

class MicroPost < ActiveRecord::Base
  belongs_to :user
end

class Comment < ActiveRecord::Base
  belongs_to :user
end