Nested form not saving in rails 3.1 - ruby-on-rails

Question

Noob question, I'm sure, but I can't seem to find my mistake. SymptomSets are saving w/ the proper user_id, but the nested symptoms disappear. Note that the user model structure is identical to that in the Rails Tutorial (save that it has_many :symptom_sets)
Models:
class SymptomSet < ActiveRecord::Base
attr_accessible :symptoms, :symptoms_attributes
belongs_to :user
has_many :symptoms, :dependent => :destroy
accepts_nested_attributes_for :symptoms, allow_destroy: true
end
class Symptom < ActiveRecord::Base
attr_accessible :name, :duration, :symptom_set_id
belongs_to :symptom_set
end
Controller:
class SymptomSetsController < ApplicationController
before_filter :signed_in_user, only: [:create, :new]
def new
#symptom_set = SymptomSet.new
3.times do
symptom = #symptom_set.symptoms.build
end
end
def create
#symptom_set = current_user.symptom_sets.build(params[:symptom_sets])
if #symptom_set.save
flash[:success] = "Symptoms submitted!"
redirect_to root_url
else
render 'static_pages/home'
end
end
And the View:
<%= simple_form_for #symptom_set, :html => { :class => 'form-inline' } do |f| %>
<%= f.fields_for :symptoms do |builder| %>
<%= render 'symptom_fields', f: builder %>
<% end %>
<div class="actions"><%= f.submit %></div>
<% end %>
And the partial:
<%= f.input :name,
:collection=> ["Cough", "Fever", "Headache", "Lethargy"],
label: "Symptom",
prompt: "Select a symptom",
:input_html => { :class => "span3" }%>
<%= f.input :duration,
:collection => 1..14,
label: "Duration",
prompt: "How many days?" %>
finally, the rails server console outputs the following:
Parameters: {"utf8"=>"✓", "authenticity_token"=>"s7ksuk40M2r76Nq4PGEEpTpkCECxFniP4TtpfSHszQk=", "symptom_set"=>{"symptoms_attributes"=>{"0"=>{"name"=>"Cough", "_destroy"=>"false", "duration"=>"2"}, "1
"=>{"name"=>"Fever", "_destroy"=>"false", "duration"=>"2"}, "2"=>{"name"=>"", "_destroy"=>"1", "duration"=>""}}}, "commit"=>"Create Symptom set"}
User Load (0.4ms) SELECT "users".* FROM "users" WHERE "users"."remember_token" ='OH6_nuvySNjd6AbTuDunsw' LIMIT 1
(0.1ms) BEGIN
SQL (0.4ms) INSERT INTO "symptom_sets" ("created_at", "updated_at", "user_id") VALUES ($1, $2, $3)
RETURNING "id" [["created_at", Tue, 05 Feb 2013 21:12:07 UTC +00:00], ["updated_at", Tue, 05 Feb 20
13 21:12:07 UTC +00:00], ["user_id", 1]]
(1.1ms) COMMIT

Answer 1

I'd try changing:
#symptom_set = current_user.symptom_sets.build(params[:symptom_sets])
to:
#symptom_set = current_user.symptom_sets.new(params[:symptom_sets])
I don't know if build would work there.
And also checking the params on the terminal log if it is called symptom_sets and if it's sending the parameters of nested form attributes.
EDIT:
I Really think your param's name would be symptom_set in singular. check that.