Question

I am having an issue with the below code in one of my views:

<% @blog.comments.each do |comment| %>
<h3><%= comment.user.email %></h3>
</div>
<% end %>

Which is producing an error:

NoMethodError in Blogs#show
...
undefined method `email' for nil:NilClass

The below code however works without error:

<% @blog.comments.each do |comment| %>
<%= comment.body %>
<% end %>

Comment is declared as:

class Comment < ActiveRecord::Base
  belongs_to :blog
  belongs_to :user
end

And the email attribute is accessible in another view as:

<% @users.each do |user| %>
  <tr>
    <td><%= link_to user.username, user %></td>
    <td><%= user.email %></td>
  </tr>
<% end %>

To me it looks like comment.user isn’t being recognised as an instance of User model. What am I doing wrong?

Answer 1

You need to check that comment.user isn’t nil before trying to call a method on it. An if statement can do this for you:

<% @blog.comments.each do |comment| %>
  <h3><%= comment.user.email if comment.user %></h3>
  </div>
<% end %>