Keep getting: ActiveRecord::UnknownAttributeError in PartiesController#create? - ruby-on-rails

Question

I keep getting ActiveRecord::UnknownAttributeError in PartiesController#create:
I have three models: Party, Products, Traits.
class Party < ActiveRecord::Base
has_many :products
accepts_nested_attributes_for :products
end
class Product < ActiveRecord::Base
belongs_to :party
has_many :traits
accepts_nested_attributes_for :traits
end
class Trait < ActiveRecord::Base
belongs_to :product
end
The party form:
<%= form_for(#party) do |f| %>
<% if #party.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(#party.errors.count, "error") %> prohibited this party from being
saved:</h2>
<ul>
<% #party.errors.full_messages.each do |msg| %>
<li><%= msg %></li>
<% end %>
</ul>
</div>
<% end %>
<div class="field">
<%= f.label :name %><br />
<%= f.text_field :name %>
</div>
<table>
<%= f.fields_for :products do |builder| %>
<tr>
<td> <%= builder.label :shirt, "Shirt " %> </td>
<td> <%= builder.text_field :shirt %> </td>
<%= f.fields_for :traits do |builder| %>
<td><%= builder.label :color, "Color" %></td>
<td><%= builder.text_field :color %></td>
<td><%= builder.label :quantity, "Quantity" %></td>
<td><%= builder.number_field :quantity %></td>
</tr>
<tr>
<td><%= builder.label :pants, "Pants " %></td>
<td><%= builder.text_field :pants %></td>
<td><%= builder.label :color, "Color" %></td>
<td><%= builder.text_field :color %></td>
<td><%= builder.label :quantity, "Quantity" %></td>
<td><%= builder.number_field :quantity %></td>
</tr>
<% end %>
<% end %>
</table>
<div class="actions">
<%= f.submit %>
</div>
<% end %>
The parties controller:
class PartiesController < ApplicationController
def new
#party = Party.new
1.times do
product = #party.products.build
2.times {product.traits.build}
end
end
def create
#party = Party.new(params[:party])
respond_to do |format|
if #party.save
format.html { redirect_to #party, notice: 'Party was successfully created.' }
format.json { render json: #party, status: :created, location: #party }
else
format.html { render action: "new" }
format.json { render json: #party.errors, status: :unprocessable_entity }
end
end
end
The show page:
<%= notice %>
This is <%= #party.name %>'s registry:
<table>
<% for product in #party.products %>
<tr>
<td>Shirt</td>
<td> <%= product.shirt %> </td>
<% for trait in #product.traits %>
<td>Color</td>
<td> <%= trait.color %> </td>
<td>Quantity</td>
<td> <%= trait.quantity %> </td>
</tr>
<tr>
<td>Pants</td>
<td> <%= product.pants %> </td>
<td>Color</td>
<td> <%= trait.color %> </td>
<td>Quantity</td>
<td> <%= trait.quantity %> </td>
</tr>
<% end %>
</table>
<%= link_to 'Edit', edit_party_path(#party) %> |
<%= link_to 'Back', parties_path %>
<% end %>
I've tried everything. What am I missing? Thanks people!

Answer 1

So the params[:party] hash probably contains elements from the form that are not attributes of Party. To debug, try:
def create
#party = Party.new(:name => params[:party][:name])
I think the real complication is that Traits are nested under Products which are nested under Party. This is why the fields_for method for Traits needs to be `builder.fields_for :traits do |traits_fields|' (although I think you could put "builder" instead of "traits_fields".
Then for all of the traits fields, use <%= traits_fields.label :pants, "Pants " %>
Then it should work the way you had it:
def create
#party = Party.new(params[:party])

Answer 2

The error in parameter traits, when it should be "products_attributes"=>{"traits_attributes" => ....
Try this: <%= builder.fields_for :traits do |traits_fields| %> instead of: <%= f.fields_for :traits do |builder| %>