Question

I’ve got an app that sets timed challenges for users. Each user is associated with one or more challenges. I’ve setup the models so they connect via a join table. That works fine, but I’m having problems on my view level. In the index view for the challenges, data from the challenge model and from the user model are displayed. But where the view should display the user’s name, it’s just displaying “User.” If you click on “User”, you are taken to the correct “show” page for that user. So the link works fine, but I can’t get the user’s name to appear. Instead, I’m just getting the class name to appear. Any idea why?

Here’s the code for the view. The file directly below is is views/challenges/index.html.erb

        <%- model_class = Challenge.new.class -%>
        <h1><%=t '.title', :default => model_class.model_name.human.pluralize %></h1>
        <table class="table table-striped">
          <thead>
            <tr>
              <th><%= model_class.human_attribute_name(:date) %></th>
              <th><%= model_class.human_attribute_name(:time) %></th>
              <th><%= model_class.human_attribute_name(:rider) %></th>
              <th><%=t '.actions', :default => t("helpers.actions") %></th>
            </tr>
          </thead>
          <tbody>
            <% @challenges.each do |challenge| %>
              <tr>
                <td><%= link_to challenge.date, challenge_path(challenge) %></td>
                <td><%= link_to challenge.duration, challenge_path(challenge) %></td>
                <td><%= link_to challenge.users.name, user_path(challenge) %></td>
              </tr>
            <% end %>
          </tbody>
        </table>

And here’s the relevant models.
Challenge.rb

class Challenge < ActiveRecord::Base
  attr_accessible :date, :duration, :user

  has_many :user_challenges
  has_many :users, :through  => :user_challenges
  validates_presence_of :date, :duration

  def self.winner
    Challenge.find(:first, :order => "duration desc")
  end

end

User.rb

  class User < ActiveRecord::Base
    attr_accessible :name, :email

    has_many :user_challenges
    has_many :challenges, :through => :user_challenges

    validates_presence_of :name, :email
    validates_uniqueness_of :email

    def self.find_or_create(name, email)
      user = User.find_by_email(email)
      if user.present?
        user.challenge = challenge
        user.save
      else
        User.create(:name => name, :email => email)
      end
    end
  end

Join table, aka User_challenge.rb

class UserChallenge < ActiveRecord::Base
  belongs_to :challenge
  belongs_to :user
end

Answer 1

challenge.users is a collection and .name is a ruby method that gives you the name of the class:

ruby-1.9.2-head :002 > Object.name
 => "Object" 

Call the attribute something else (username).

Also, user_path(challenge) doesn’t really make sense when a Challenge can have_many :users (which users path should it be?).