Question

I have two types of users: managers, and employees. I use one User controller for both of them.

What I did was add :manager_id to the user table, and put the following in the user model:

class User < ActiveRecord::Base
has_many :employees, :class_name => 'User', :foreign_key => :manager_id
belongs_to :manager, :class_name => 'User'

Sounds simple enough.

But now I want to define the user type. If an user has a manager, he is an employee. If a user has no manager, he is a manager.

What do I need to add to the model so I reference the user type in my views like such:

<% if current_user.manager? %>
You are a manager.
<% else %>
You are not a manager.
<% end %>

I tried to define the user type in the user.rb model but I’m getting an “undefined method ‘manager?’ for nil:NilClass” error :

def manager?
    manager_id.nil?
end

def employee?
    !manager?
end

Answer 1

Like Ryan Bigg said, you need to check out the error message a little closer. It isn’t that manager? doesn’t exist as a method on an instance of User, it’s that it doesn’t exist on Nil. When there isn’t a current_user, current_user returns nil, which you then call manager? on.

Try this to avoid this error:

<% if current_user && current_user.manager? %>
  Manager!
<% elsif current_user %>
  Not a manager, but a user!
<% else %>
  Not even a user.
<% end %>