undefined method 'user_id'

Question

I'm running Rails version 3.2.6 and Ruby version 1.9.3p545.

I installed the latest version of Bootstrap, and not the version found in the videos (maybe that is the problem). Or maybe it is another unseen compatibility issue with "simple_form." I will investigate how to install an older version of Bootstrap, but I am tired of uninstalling and reinstalling.

I would like to finish this track smoothly without error pages every 5 minutes. I have put so much work into this version of the track. I would like to finish this step (Creating a Simple RoR Application) before updating to the newer version.

My code matches the code found in the video.

<%= simple_form_for(@status, html: {class: "form-horizontal"}) do |f| %>
  <% if @status.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(@status.errors.count, "error") %> prohibited this status from being saved:</h2>

      <ul>
      <% @status.errors.full_messages.each do |msg| %>
        <li><%= msg %></li>
      <% end %>
      </ul>
    </div>
  <% end %>

  <%= f.input :user_id %>
  <%= f.input :content %>
  <div class="form-actions">
    <%= f.button :submit %>
  </div>
<% end %>

class Status < ActiveRecord::Base
  attr_accessible :content, :user_id
end

Jason Seifer Jim Hoskins James Barnett

Answer 1 · 2014-05-31T16:32:14Z

May 31, 2014 4:32pm

Do you have any users in your database?

What you're doing is specifically setting the id of a user record to 1 on your status model, right?

So when you are going to the show page for that status, rails automatically sees the user_id column on the status model and thinks "Oh I need to load the User with an id of 1 for this status!", but what's happening is since that user does not exist in the database, rails ends up sending the object nil. Then in the view when you call @status.user.first_name you're calling the method first_name for the object nil. That method doesn't existing for nil, which is why you're seeing:

undefined method `first_name' for nil:NilClass

Try navigating to http://localhost:3000/users/sign_up and create a new user. Once you have a user created it will automatically be assigned the id of 1. Then go back to your statuses show page, and it should work!

I hope that makes sense, it's Saturday and I had a long week :P

Answer 2 · 2014-05-30T21:58:33Z

May 30, 2014 9:58pm

Hi Garan!

Ok, I believe I know what may be going on. It looks like you created an empty migration, then ran it, and then added the code to change the table schema. The issue here is that if you try to run the migration again, rails will not do it because it thinks that it already ran it. So to fix this we need to do what's called a rollback (http://guides.rubyonrails.org/migrations.html#rolling-back).

Basically we are going to "undo" our previous migration. So in console type:

bundle exec rake db:rollback

Once you have successfully rolled back, try running bundle exec rake db:migrate again to run your actual code.

If this still doesn't solve the problem.. You can completely wipe your database and restart:

bundle exec rake db:drop
bundle exec rake db:create
bundle exec rake db:migrate

Let me know if this doesn't make sense! I hope it helps!

Answer 3 · 2014-05-30T05:14:53Z

May 30, 2014 5:14am

When you created the Status model, did you add a user_id column?

A quick way to find out, is to go to terminal and load up your console rails c and then build a new status object s = Status.new. Do you see an attribute that reads user_id: nil?

Another way to check is to go through your database migrations and see if perhaps you misspelled it or possibly forgot it?

This error usually means rails is trying to call .user_id on your model and it doesn't find anything. Part of the magic of rails is that it maps each database column name as an attribute to your model (check out arel here for some info https://github.com/rails/arel)

Answer 4 · 2014-05-30T16:59:35Z

May 30, 2014 4:59pm

class AddUserIdToStatuses < ActiveRecord::Migration
  def change
    add_column :statuses, :user_id, :integer
    add_index :statuses, :user_id
    remove_column :statuses, :name

  end
end

From the code that I pasted in this reply, I believe that I added the user_id column correctly (db > migrate > add_user_id_to_status).

I followed your instructions ("rails c" and then I built a new status object "s = Status.new), and the error message is the same (the same error message when I attempt to post a new status from the browser). I also tried from the terminal, and I was alerted with this error message:

irb(main):001:0> s = Status.new => #<Status id: nil, name: nil, content: nil, created_at: nil, updated_at: nil>

And no, I did not see "user_id: nil"

I checked in my database migrations, and I did not misspell anything, nor did I forget anything.

I'll read over the rails/arel that is in your reply, but I am not very familiar with Ruby on Rails, so I do not know if the literature will help much.

Thanks for responding. Nick Fuller

Answer 5 · 2014-05-30T17:01:58Z

May 30, 2014 5:01pm

Try running in console rake db:migrate

Answer 6 · 2014-05-30T17:04:07Z

May 30, 2014 5:04pm

Ran it, and the error code is the same.

Answer 7 · 2014-05-30T17:20:45Z

May 30, 2014 5:20pm

Interesting, is your code on github? Could you provide me with a link?

Answer 8 · 2014-05-30T17:21:20Z

May 30, 2014 5:21pm

Fo sho, I'll add you to my repository. I assume you are the Nick Fuller on github...

Answer 9 · 2014-05-30T17:43:20Z

May 30, 2014 5:43pm

nfuller52

can you give me a link too?

Answer 10 · 2014-05-30T17:45:12Z

May 30, 2014 5:45pm

https://github.com/garanguillory/treebook

Is this what you need?

Answer 11 · 2014-05-30T17:53:36Z

May 30, 2014 5:53pm

yes! do you have any pending commits that need to pushed? it seems your migration file is empty

Answer 12 · 2014-05-30T17:57:48Z

May 30, 2014 5:57pm

I'll commit all that I have changed recently. One second.

Answer 13 · 2014-05-30T18:01:59Z

May 30, 2014 6:01pm

Committed every thing, let me know if that worked.

Thanks.

Answer 14 · 2014-05-31T09:02:23Z

May 31, 2014 9:02am

Your solution worked... for a second, and then I ran into more problems. This is what I see when I try to update a status with the user id of "1":

NoMethodError in Statuses#show

Showing /Users/garanguillory/treehouse/projects/treebook/app/views/statuses/show.html.erb where line #5 raised:

undefined method `first_name' for nil:NilClass

Extracted source (around line #5):

2: 3: 4: Name: 5: <%= @status.user.first_name %> 6: 7: 8:

Rails.root: /Users/garanguillory/treehouse/projects/treebook

I have watched the video several times (Creating Relationships), and my code still does not cooperate. Nick Fuller Thanks in advance for the help.

Answer 15 · 2014-06-01T00:00:57Z

June 1, 2014 12:00am

Thanks for all the help. I'm cruising now. You are a genius. Nick Fuller

Answer 16 · 2014-06-01T01:51:52Z

June 1, 2014 1:51am

good man keep it up! it's all the fun of learnin

Welcome to the Treehouse Community

Looking to learn something new?

Garan Guillory

Garan Guillory

undefined method 'user_id'

16 Answers

Nick Fuller

Nick Fuller

Nick Fuller

Nick Fuller

Nick Fuller

Nick Fuller

Garan Guillory

Garan Guillory

Nick Fuller

Nick Fuller

Garan Guillory

Garan Guillory

Nick Fuller

Nick Fuller

Garan Guillory

Garan Guillory

Nick Fuller

Nick Fuller

Garan Guillory

Garan Guillory

Nick Fuller

Nick Fuller

Garan Guillory

Garan Guillory

Garan Guillory

Garan Guillory

Garan Guillory

Garan Guillory

Garan Guillory

Garan Guillory

Nick Fuller

Nick Fuller