Rails - storing values in join table - ruby-on-rails

Question

I am trying to store client_id in join table: clients_orders after submitting the form below.
I set the tables in this way so I can look up all the orders a client has made.
I am using rails 4 with devise and simple form.
models
class Order < ActiveRecord::Base
belongs_to :user
#has_and_belongs_to_many :clients
belongs_to :clients #solution
end
class Client < ActiveRecord::Base
#has_and_belongs_to_many :orders
as_many :orders, dependent: :destroy #solution
end
orders form
<%= simple_form_for(#order) do |f| %>
<%= f.error_notification %>
<%= f.association :client, collection: Client.all, label_method: :name, value_method: :id, prompt: "Choose a Client" } %>
<%= etc... %>
<%= f.submit %>
<% end %>
with the current code above, the join table clients_orders does not update
create_table "clients_orders", id: false, force: true do |t|
t.integer "client_id"
t.integer "order_id"
end
order controller
class OrdersController < ApplicationController
# GET /orders/new
def new
#order = Order.new
end
# POST /orders
# POST /orders.json
def create
#order = Order.new(order_params)
#order.user_id = current_user.id
respond_to do |format|
if #order.save
format.html { redirect_to #order, notice: 'Order was successfully created.' }
format.json { render :show, status: :created, location: #order }
else
format.html { render :new }
format.json { render json: #order.errors, status: :unprocessable_entity }
end
end
end
# Never trust parameters from the scary internet, only allow the white list through.
def order_params
params.require(:order).permit(:code, :client_id, :user_id, :memo, :status, items_attributes: [:id, :name, :_destroy])
end
end

Answer 1

For future reference:
this is a simple one-to-many relationship. All you have to do to access a client's orders is to set up the has_many :orders in the User model and belongs_to :user in Order model. Then you can use collection methods like current_user.orders and it will get all of that specific user's orders for you. Just assign it to the user with #order = current_user.orders.build(:order_params)

Answer 2

You aren't whitelisting the correct parameters in your create action.
When dealing with has_and_belongs_to_many associations, you're dealing with multiple objects on each side, so the attributes you're whitelisting are plural, not singular.
You need to be whitelisting client_ids, not client_id.
Also, I'm pretty sure your form is wrong. You have it setup as though client is a has_one relationship. I think you want the plural version there as well.
<%= f.association :clients, #...
# ^----- add an 's'
If you really intended for the form to model a singular relationship, then you'll need to massage the data somewhere before saving your model. Here's one way to do it:
def create
#order = Order.new(order_params)
#order.client_ids << params[:order][:client_id]
#order.user_id = current_user.id
# save and respond...
end
If you go this route, then just remove :client_id from your parameters whitelist rather than pluralizing it.