ActiveModel::ForbiddenAttributesError for polymorphic association - ruby-on-rails

Question

There are the following models:
class Discount < ActiveRecord::Base
belongs_to :content, polymorphic: true
validates :value, presence: true
end
class TimeDiscount < ActiveRecord::Base
has_one :discount, as: :content, dependent: :destroy
validates :start_time, :end_time, presence: true
accepts_nested_attributes_for :discount
end
And the following controller:
class Admin::TimeDiscountsController < ApplicationController
def new
#time_discount = TimeDiscount.new
end
def create
#time_discount = TimeDiscount.new(time_discount_params)
if #time_discount.save
redirect_to root_path
else
render 'new'
end
end
private
def time_discount_params
params.require(:time_discount).permit.tap do |whitelisted|
whitelisted[:start_time] = params[:time_discount][:start_time]
whitelisted[:end_time] = params[:time_discount][:end_time]
whitelisted[:discount_attributes] = params[:time_discount][:content]
end
end
end
Form:
= form_for #time_discount, url: admin_time_discounts_path do |f|
.row
= f.label :start_time
= f.text_field :start_time
.row
= f.label :end_time
= f.text_field :end_time
= f.fields_for :content do |discount|
.row
= discount.label :value
= discount.text_field :value
.row
= f.submit "Добавить"
But 'create' action generates 'ActiveModel::ForbiddenAttributesError' in TimeDiscount.new line. I use Rails 4. How can I fix it? Thanks.

Answer 1

def time_discount_params
params.require(:time_discount).permit(:start_time, :end_time, content: [:id, :start_time, :end_time])
end
This is probably what you want instead of that method you have defined in the above. This is assuming you are creating it via something like this:
= form_for #time_discount, url: admin_time_discounts_path do |f|
.row
= f.label :start_time
= f.text_field :start_time
.row
= f.label :end_time
= f.text_field :end_time
= f.fields_for :content, #time_discount.content.build do |discount|
.row
= discount.label :value
= discount.text_field :value
.row
= f.submit "Добавить"
give that a go.