Rails - How to assign booking numbers to events - ruby-on-rails

Question

I'm building an events app using Ruby on Rails. Events can be either free or paid. In each instance I want to be able to assign a unique booking number for users when they book their places on an event.
What do I need to do to ensure both paid and free events are assigned a number in the server and a booking is then confirmed? Is it as simple as adding a booking_number column in my bookings table?
This is my model and controller code -
booking.rb
class Booking < ActiveRecord::Base
belongs_to :event
belongs_to :user
#validates :quantity, presence: true, numericality: { greater_than: 0 }
validates :total_amount, presence: true, numericality: { greater_than: 0 }
validates :quantity, :total_amount, presence: true
def reserve
# Don't process this booking if it isn't valid
self.valid?
# We can always set this, even for free events because their price will be 0.
#self.total_amount = booking.quantity * event.price
# Free events don't need to do anything special
if event.is_free?
save!
# Paid events should charge the customer's card
else
begin
self.total_amount = event.price_pennies * self.quantity
charge = Stripe::Charge.create(
amount: total_amount,
currency: "gbp",
source: stripe_token,
description: "Booking created for amount #{total_amount}")
self.stripe_charge_id = charge.id
save!
rescue Stripe::CardError => e
errors.add(:base, e.message)
false
end
end
#end
end
end
bookings_controller.rb
class BookingsController < ApplicationController
before_action :authenticate_user!
def new
# booking form
# I need to find the event that we're making a booking on
#event = Event.find(params[:event_id])
# and because the event "has_many :bookings"
#booking = #event.bookings.new(quantity: params[:quantity])
# which person is booking the event?
#booking.user = current_user
##total_amount = #event.price * #booking.quantity
end
def create
puts params
# actually process the booking
#event = Event.find(params[:event_id])
#booking = #event.bookings.new(booking_params)
#booking.user = current_user
if
#booking.reserve
flash[:success] = "Your place on our event has been booked"
redirect_to event_path(#event)
else
flash[:error] = "Booking unsuccessful"
render "new"
end
end
private
def booking_params
params.require(:booking).permit(:stripe_token, :quantity, :event_id, :stripe_charge_id, :total_amount)
end
end
This is my views code. There's an if/else statement here depending on whether its a paid event or not. The free events 'booking_id' simply shows as blank at the moment - not sure why.
booking.new.html.erb
<% if #event.is_free? %>
<div class="col-md-6 col-md-offset-3" id="eventshow">
<div class="row">
<div class="panel panel-default">
<div class="panel-heading">
<h2>Your Booking Confirmation</h2>
</div>
<div class="panel-body">
<h1>Hi there</h1>
<p>You have placed a booking on <%= #event.title %></p>
<p>Your order number is <%= #booking.booking_id %></p>
<p>We hope you have a wonderful time. Enjoy!</p>
<p>Love from Mama Knows Best</p>
</div>
<div class="panel-footer">
<%= link_to "Home", root_path %>
</div>
</div>
</div>
</div>
<% else %>
<div class="col-md-6 col-md-offset-3" id="eventshow">
<div class="row">
<div class="panel panel-default">
<div class="panel-heading">
<h2>Confirm Your Booking</h2>
</div>
<%= simple_form_for [#event, #booking], id: "new_booking" do |form| %>
<div class="calculate-total">
<p>
Confirm number of spaces you wish to book here:
<input type="number" placeholder="1" name="booking[quantity]" min="1" value="1" class="num-spaces">
</p>
<p>
Total Amount
£<span class="total" data-unit-cost="<%= #event.price %>">0</span>
</p>
</div>
<span class="payment-errors"></span>
<div class="form-row">
<label>
<span>Card Number</span>
<input type="text" size="20" data-stripe="number"/>
</label>
</div>
<div class="form-row">
<label>
<span>CVC</span>
<input type="text" size="4" data-stripe="cvc"/>
</label>
</div>
<div class="form-row">
<label>
<span>Expiration (MM/YYYY)</span>
<input type="text" size="2" data-stripe="exp-month"/>
</label>
<span> / </span>
<input type="text" size="4" data-stripe="exp-year"/>
</div>
</div>
<div class="panel-footer">
<%= form.button :submit %>
</div>
<% end %>
<% end %>
</div>
</div>
</div>

Answer 1

So you can use the SecureRandom Generator like this, and assuming your model is named Booking
### Add this in your model
before_create :add_booking_number
validates_uniqueness_of :add_booking_number
def add_booking_number
begin
self.booking_number = SecureRandom.hex(2).upcase
other_booking = booking_number.find_by(booking_number: self.booking_number)
end while other_booking
end
To use the Moniker "MAMA" you can do
def add_event_ident
self.booking_number = "MAMA" + '- ' + SecureRandom.hex(2).upcase
...
end
the (2) at the end of the .hex controls the length of the generated string (2) will produce 4 random letters. You can find the best length that works for you by going into rails console and playing with it ie.
SecureRandom.hex(4) ...

Answer 2

You can create a new column like booking_id in your booking table and assign a unique random before the booking object is created.
Ref: Source
If you want the random to be human readable, you can try this