Getting nested form to work rails? - ruby-on-rails

Question

I have these models:
class List < ActiveRecord::Base
has_many :list_items, :dependent => :destroy
accepts_nested_attributes_for :list_items, :reject_if => lambda { |a| a(:task.blank?)}
end
class ListItem < ActiveRecord::Base
belongs_to :list
end
and this controller:
class ListsController < ApplicationController
def index
#lists = List.order("lists.created_at DESC")
end
def show
#list = List.find(params[:id])
end
def new
#list = List.new({:name => Time.now.strftime("%A %d %B")})
3.times { #list.list_items.build}
end
def create
#list = List.new(list_params)
if #list.save
flash[:notice] = "List successfully added."
redirect_to(:action => 'index')
else
render(:action => 'new')
end
end
def edit
#list = List.find(params[:id])
end
def update
#list = List.find(params[:id])
if #list.update_attributes
flash[:notice] = "List updated successfully."
redirect_to(:action => 'index')
else
render(:action => 'edit')
end
end
def delete
#list = List.find(params[:id])
end
def destroy
#list = List.find(params[:id]).destroy
flash[:notice] = "List successfully deleted"
redirect_to(:action => 'index')
end
private
def list_params
params.require(:list).permit(:name, :task)
end
end
and this form:
<%= form_for #list do |f| %>
<p>
<%= f.label :name %><br />
<%= f.text_field :name %>
</p>
<%= f.fields_for :list_items do |builder| %>
<p>
<%= builder.label :task %><br />
<%= builder.text_field :task %>
</p>
<% end %>
<p><%= f.submit "Create" %></p>
<% end %>
You can probably see what I am trying to do -> create a form where it creates a new list and then adds task to that list but for some reason whenever I hit submit on the form the name stays but tasks don't save?

Answer 1

I solved the problem turns out i needed to add the list_item attributes to the list controller. I was trying to do this the rails 3 way in teh model with attr_accessible which kept giving me an error. I needed to update the controller to have this at the bottom:
def list_params
params.require(:list).permit(:name, :list_items_attributes => :task)
end