Question

Using devise for authentication, undefined method 'size' for nil:NilClass is raised from the following view code:

<% @relationships.each do |relationship| %>
  <div><%= relationship.box.size  %></div>
<% end %>

only when I define @relationships in my controller as

@relationships = current_user.relationships

but not when I define it as

@relationships = User.find(current_user.id).relationships

Shouldn’t those two definitions be identical?

I have the following associations:

class Relationship < ActiveRecord::Base

  belongs_to :user
  belongs_to :box

end

class User < ActiveRecord::Base

  has_many: :relationships
  has_many: :boxes, through: :relationships

end

class Box < ActiveRecord::Base

  has_many: :relationships
  has_many: :users, through: :relationships

end

I hope I’ve provided the right information; this is the first time I haven’t been able to find an answer on stack overflow. Thanks in advance!

Answer 1

I had created another object through current_user (current_user.relationships.new) in the same action:

@relationship = current_user.relationships.new
@relationships = current_user.reload.relationships #reload required

After making the following change to the first assignment, the reload call could be removed:

@relationship = Relationship.new
@relationships = current_user.relationships

Special thanks to @AmitKumarGupta for helping a newbie out!