How can I lessen the verbosity of my populate method? - ruby-on-rails

Question

I wrote a form object to populate an Order, Billing, and Shipping Address objects. The populate method looks pretty verbose. Since the form fields don't correspond to Address attributes directly, I'm forced to manually assign them. For example:
shipping_address.name = params[:shipping_name]
billing_address.name = params[:billing_name]
Here's the object. Note that I snipped most address fields and validations, and some other code, for brevity. But this should give you an idea. Take note of the populate method:
class OrderForm
attr_accessor :params
delegate :email, :bill_to_shipping_address, to: :order
delegate :name, :street, to: :shipping_address, prefix: :shipping
delegate :name, :street, to: :billing_address, prefix: :billing
validates :shipping_name, presence: true
validates :billing_name, presence: true, unless: -> { bill_to_shipping_address }
def initialize(item, params = nil, customer = nil)
#item, #params, #customer = item, params, customer
end
def submit
populate
# snip
end
def order
#order ||= #item.build_order do |order|
order.customer = #customer if #customer
end
end
def shipping_address
#shipping_address ||= order.build_shipping_address
end
def billing_address
#billing_address ||= order.build_billing_address
end
def populate
order.email = params[:email]
shipping_address.name = params[:shipping_name]
shipping_address.street = params[:shipping_street]
# Repeat for city, state, post, code, etc...
if order.bill_to_shipping_address?
billing_address.name = params[:shipping_name]
billing_address.street = params[:shipping_street]
# Repeat for city, state, post, code, etc...
else
billing_address.name = params[:billing_name]
billing_address.street = params[:billing_street]
# Repeat for city, state, post, code, etc...
end
end
end
Here's the controller code:
def new
#order_form = OrderForm.new(#item)
end
def create
#order_form = OrderForm.new(#item, params[:order], current_user)
if #order_form.submit
# handle payment
else
render 'new'
end
end
Noe I am not interested in accepts_nested_attributes_for, which presents several problems, hence why I wrote the form object.

Answer 1

def populate
order.email = params[:email]
shipping_params = %i[shipping_name shipping_street]
billing_params = order.bill_to_shipping_address? ?
shipping_params : %i[billing_name billing_street]
[[shipping_address, shipping_params], [billing_address, billing_params]]
.each{|a, p|
a.name, a.street = params.at(*p)
}
end

Answer 2

How about
class Order < ActiveRecord::Base
has_one :shipping_address, class_name: 'Address'
has_one :billing_address, class_name: 'Address'
accepts_nested_attributes_for :shipping_address, :billing_address
before_save :clone_shipping_address_into_billing_address, if: [check if billing address is blank]
Then when you set up the form, you can have fields_for the two Address objects, and side step the populate method entirely.

Answer 3

A possible fix would be to use a variable for retrieving those matching params, like so:
def populate
order.email = params[:email]
shipping_address.name = params[:shipping_name]
shipping_address.street = params[:shipping_street]
# etc...
#set a default state
shipping_or_billing = "shipping_"
#or use a ternary here...
shipping_or_billing = "billing_" if order.bill_to_shipping_address?
billing_address.name = params["shipping_or_billing" + "name"]
billing_address.street = params["shipping_or_billing" + "street"]
...
end

Answer 4

Your address classes should probably have a method that would set the values for all the address properties from a hash that it would receive as an argument.
That way your populate method would only check for order.bill_to_shipping_address? and them pass the correct dictionary to the method I'm suggesting.
That method on the other hand, would just assign the values from the hash to the correct properties, without the need for a conditional check.