Question

I am trying to create an activity feed with the most recent activities from my TrainingSession model.

class User
  has_many :training_sessions
end

class TrainingSession
  belongs_to :user
end

The problem is that I am trying to access a user’s data in the view page (mainly the user’s name) by instantiating an object from the TrainingSessions database table, as shown below:

<% @training_sessions.each do |training_session| %>
<%= training_session.user_id %>

The problem is that, although I successfully get the user’s id, I cannot call, for example:

training_session.user_id.name

… otherwise I get the NoMethodError shown below:

undefined method `first_name' for 2:Fixnum

so my question is … how can I access the user’s data from the TrainingSession’s object?

any help would be much appreciated. Pretty stumped on this one.

Answer 1

The reason that you get a “undefined method `name’ for nil:NilClass”-error is that some training sessions do not belong to a user. The solution is to cleanup your database:

DELETE FROM training_sessions WHERE user_id IS NULL

If it is expected behavior to have training sessions that don’t belong to a user, you have to check that the user is not nil in your loop:

<% @training_sessions.each do |training_session| %>
  <% unless training_session.user.nil? %>
    <%= training_session.user.name %>
  <% end %>
<% end %>