Simple form- select collection and set up has_many through - ruby-on-rails

Question

How to display products divided into three parts(three different filter like: product_1, product_2, product_3 ) and need choose only one product from each part
After submit. I should to save all that products for one order.
I have 4 tables:
Users
Orders
Order_details
Products
class Order < ActiveRecord::Base
has_many :order_details
belongs_to :user
has_many :products, through: :order_details
accepts_nested_attributes_for :order_details
end
class OrderDetail < ActiveRecord::Base
belongs_to :order
belongs_to :product
end
class Product < ActiveRecord::Base
has_many :order_details
has_many :orders, through: :order_details
def self.get_first_course
Product.where(product_type: "exem_product_1")
end
def self.get_main_course
Product.where(product_type: "exem_product_2")
end
def self.get_drink
Product.where(product_type: "exem_product_3")
end
end
I am not sure how to write strong params for that situation and how create that objects for save data.
class OrdersController < ApplicationController
before_action :authenticate_user!
def index
#order = Order.new
#I think need something like this..?!
##order.order_details.build
end
def create
end
private
def order_params
params.require(:order).permit(:date, :product_id => [])
end
end

Answer 1

You can do something like this in your controller:
class OrdersController < ApplicationController
before_action :authenticate_user!
def index
#order = Order.all
end
def new
#order = Order.new
end
def create
#order = current_user.orders.new(order_params)
if #order.save
#your actions here
else
#your actions to rescue error
end
end
private
def order_params
params.require(:order).permit(:date, :product_id => [])
end
end
And to use simple form for radio button collections, you have to do something like this:
= simple_form_for(#order, html: {:class => 'well form-horizontal', :method => :post, :action=> :create }) do |f|
.col-xs-12.col-sm-6.col-md-8
= render 'shared/error_messages', object: f.object
= f.collection_radio_buttons :product_ids, Product.get_first_course, :id, :product_name, :item_wrapper_class => 'inline'
%hr
= f.collection_radio_buttons :product_ids, Product.get_main_course, :id, :product_name, :item_wrapper_class => 'inline'
%hr
= f.collection_radio_buttons :product_ids, Product.get_drink, :id, :product_name,,:item_wrapper_class => 'inline'
%hr
= f.association :products, as: :radio_buttons
= f.button :submit, class: "btn btn-primary"

Answer 2

for select collection and get 3 different ids from form, that works for me..
post:
~ products_ids => {array ids}
= simple_form_for #order do |f|
= render 'shared/error_messages', object: f.object
= simple_fields_for :product_ids do |product|
= product.collection_select(nil, Product.get_first_course, :id, :product_name,
{prompt: "Select first course" },class: "form-control product-select")
= product.collection_select(nil, Product.get_main_course, :id, :product_name,
{prompt: "Select first course"},class: "form-control product-select")