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Ruby

Posted by Stephen Whitfield
Stephen Whitfield
16,771 Points

undefined method `full_name' for nil:NilClass

For some reason, this error keeps coming up when I try to load my index file.

Here's my status.rb: 

class User < ActiveRecord::Base
  # Include default devise modules. Others available are:
  # :token_authenticatable, :confirmable,
  # :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable

  # Setup accessible (or protected) attributes for your model
  attr_accessible :email, :password, :password_confirmation, :remember_me, :first_name, :last_name, :profile_name

  has_many :statuses

  def full_name
    return first_name+' '+last_name
  end
end

Index.html file:

<div class="page-header">
<h1>Friend Statuses</h1>
</div>

<%= link_to "Post a New Status", new_status_path, class: "btn btn-success" %>

<% @statuses.each do |status| %>
<div class="status">
    <strong><%= status.user.full_name %></strong> <!-- bold -->
    <p><%= status.content %></p>
    <div class="meta">
        <%= link_to time_ago_in_words(status.created_at)+" ago", status %>
        <span class="admin">
            | <%= link_to "Edit",  edit_status_path(status) %> |
            <%= link_to "Delete", status, method: :delete, data: {confirm: "Are you sure?"} %>
        </span>
    </div>
</div>
<% end %>

7 Answers

Josh Flowers
Josh Flowers
7,010 Points

You didn't state your error.

My question is which version of Ruby and Rails are you using? If you're using Ruby 2.x, then the attr_accessible won't work as it's been dropped from the language due to security concerns.

So, if you're using Ruby 2.x and Rails 4.x then you're going to keep running into problems. Treehouse is currently working on updates for these new versions, so my advise would be to take a break and learn something else until they release it, or start over using the same versions of Ruby and Rails that they use.

Cheers.

Stephen Whitfield
Stephen Whitfield
16,771 Points

The error is the title of my post. Thanks!

Michael Wiss
Michael Wiss
19,233 Points
Michael Wiss
Michael Wiss
19,233 Points

waiting for that update.

Josh Flowers
Josh Flowers
7,010 Points

I got an email for Jason Seifer two days ago saying that the Rails 4 version will come out soon.

Michael Wiss
Michael Wiss
19,233 Points

huzzah!

Josh Flowers
Josh Flowers
7,010 Points

Although the word "soon" is quite relative.

Michael Wiss
Michael Wiss
19,233 Points

Have you tried the Lynda.com course?

Josh Flowers
Josh Flowers
7,010 Points

No, I thought it was also on Rails 3? There's a good free book http://ruby.railstutorial.org/ruby-on-rails-tutorial-book which is written by the creator or Rails and it's on Rails 4. It's very good and comes highly recommended.

Stephen Whitfield
Stephen Whitfield
16,771 Points

Have any of you two tried moving on with that portion of the tutorial by referring back to the docs and learning it yourselves? I just might do that tonight. Figure it's better practice to sort of teach yourself concepts without having someone else do it for you.

Michael Wiss
Michael Wiss
19,233 Points

Yes. I made some progress after using

'''#use attr_accessible in ruby 4 gem 'protected_attributes' '''

but ran into more setbacks.

Michael Wiss
Michael Wiss
19,233 Points

Yes I used this gem:

#use attr_accessible in ruby 4
gem 'protected_attributes'

but ran into more setbacks.

Stephen Whitfield
Stephen Whitfield
16,771 Points

darn. maybe it's best to wait until they update it after all. guess i'll move on to other modules.

Jeff Wilson
PLUS
Jeff Wilson
Courses Plus Student 25,216 Points
Jeff Wilson
Jeff Wilson
Courses Plus Student 25,216 Points

I ran into the same problem last week and since reading about the changes they've made in Rails 4 I think it's worth understanding the change and seeing if you can make it work.

Basically as of Rails 4 attr_accessible has been removed and they want you to use Strong Parameters method as it allows for a better separation of concerns by moving the rules to the controller rather than the model. It's also better from a security standpoint.

I got my code working by doing the following: 1) I added a private class in the statuses controller that follows the strong parameters method

'' 'ruby def status_params params.require(:status).permit(:date, :content).merge(user_id: current_user.id) end '''

2) I updated the the status's model to include ''' ruby accepts_nested_attributes_for :User ''' which establishes the relationship for the strong parameters

You can read about strong parameters here: http://robots.thoughtbot.com/strong-parameters-as-documentation http://weblog.rubyonrails.org/2012/3/21/strong-parameters/

BTW - strong parameters exist in Rails 3 so you can try them out regardless of which version you're running.

Stephen Whitfield
Stephen Whitfield
16,771 Points

Awesome! Thanks Jeff.

minzawmra
PLUS
minzawmra
Courses Plus Student 15,682 Points
minzawmra
minzawmra
Courses Plus Student 15,682 Points

Found a solution here: http://gorails.com/blog/rails-4-0-and-devise-with-strong-params-and-custom-fields

It works!

Stephen Whitfield
Stephen Whitfield
16,771 Points

Thanks! I'll give it a shot.

Brandon Barrette
Brandon Barrette
20,485 Points
Brandon Barrette
Brandon Barrette
20,485 Points

So the error isn't that full_name is not defined. The error is that you are trying to call full_name on Nil, meaning there is no user defined. My guess is that the user_id is not being stored with the status in the database. Like Josh Flowers said, using Rails 4 with these tutorials is going to give you constant headaches. I would learn using Rails 3.2 and worry about first learning how Rails works, than trying to use the most recent (and still very new) version.

Stephen Whitfield
Stephen Whitfield
16,771 Points

Hey Brandon. Thanks for the reply. I have already taken Josh's advice. My intention wasn't to install the latest version of Rails--it was to install Rails as per the instructions supplied (sudo gem install rails). It was by chance that the latest version was the one that was installed. Now that I know that the latest version doesn't support attr_accessible, I know that my understanding of Rails isn't the problem.

Michael Wiss
Michael Wiss
19,233 Points
Michael Wiss
Michael Wiss
19,233 Points

I installed RVM and now have multiple versions of Rails to use. I found this useful

Stephen Whitfield
Stephen Whitfield
16,771 Points

Thanks for the heads-up! From the reviews, it looks like a life-saver.

Steven Lacks
Steven Lacks
18,214 Points
Steven Lacks
Steven Lacks
18,214 Points

This should actually work in rails 4/4.1, the problem for me wasn't a version issue. If the tests work, this should work. It's because we previously went in and updated friends before the models/controllers were finished. I used SQLite3 database browser to delete all the incomplete entries and voila! it started working even in 4.1

I still recommend doing it in the correct version if possible. RVM is cool.