Question

I’m having trouble getting my view to render. I think I know why I’m getting the error:

undefined method `name' for nil:NilClass

Extracted source (around line #21): (showing 18-24)

<ul>
     <%= form_tag(default_hero_user_path, :method=>'post') do %>
         <%= label_tag "Name" %>
         <%= text_field_tag "name", @user.default_hero.name %> #line 21
         <%= submit_tag 'Set hero', class: "btn btn-large btn-primary"  %>
     <% end %>
   </ul>

I know you can’t call .name on a nil object but I don’t understand why @user.default_hero is nil. I want the user to be able to set their ‘hero’ but having trouble setting the default obviously.

Here is the users controller:

# creates or updates the default hero
def default_hero
 @user = User.find(params[:id])
 hero = @user.default_hero
 if hero.nil?
   # we don't have a default hero so we need to add one'
   hero = Hero.new
   @user.heros << hero
 end
 hero.default = true
 hero.name = params[:name]
 hero.save
 redirect_to @user # shows the user again to see any updates
end

And here is where I believe I am having the problem in setting a default view-

def show
@user = User.find(params[:id]) 
if @user.default_hero.nil?
  name = params[:q]
else
  name = @user.default_hero.name
end

Thanks for your guys’ time and attention if you can point me in the right direction in how to solve this I would ppreciated.

Answer 1

Your show controller action doesn’t make much sense. You are setting a local variable (which won’t be accessible in the view) if @user.default_hero.nil?. This doesn’t accomplish anything and @user.default_hero will still be nil in the view.

That being said, to get rid of your error you can simply do this:

<%= text_field_tag "name", @user.default_hero.nil? ? '' : @user.default_hero.name %>

---

Based on your comment I would does something like this:

Model

class User < ActiveRecord::Base
  has_many :heros

  def set_default_hero(name)
    hero = self.heros.find_by_name(name) # check if the hero exists already
    hero = self.heros.build(:name => name) if hero.nil? # new object if not
    hero.default = true # set it as default
    hero.save
  end
end

Controller:

def default_hero
  @user = User.find(params[:id])
  @user.set_default_hero(params[:name])
  redirect_to @user
end

def show
  @user = User.find(params[:id])
  @default_hero = @user.default_hero.nil? ? '' : @user.default_hero.name
end

View:

<%= text_field_tag "name", @default_hero %>

You ignored my question about params[:q], so I don’t know what to do with that.