of_fitness_camp_location_validator.rb

class OfFitnessCampLocationValidator < ActiveModel::EachValidator
  def validate_each(record, attribute, value)
    unless record.time_slot.fitness_camp.location_id.to_s == record.user.location_id.to_s
      record.errors[attribute] << (options[:message] || "A user and time slot must share the same location")
    end
    if record.time_slot.fitness_camp.time_slots.map{|ts| ts.registrations}.flatten.map(&:user_id).include?(record.user.id)
      record.errors[attribute] <<  (options[:message] || "A user can only register for one time_slot in a camp")
    end
  end
end

registration.rb

class Registration

  include Mongoid::Document
  include Mongoid::Timestamps
  include ActiveModel::Validations

  belongs_to :user
  belongs_to :time_slot  # , :null => false
  belongs_to :order
  has_many :friends
  belongs_to :fitness_camp

  validates :user, presence: true, of_fitness_camp_location: true

  # does this do anything? is this deprecated?
  
#  def self.produce_registration(cart_item)
#    rsg = self.new
#    rsg.time_slot_id = cart_item.fitnesscamp.id
#    rsg.order_id = cart_item.order
#    rsg
#  end

end

registration_spec.rb

require 'spec_helper'

describe Registration do

  before(:each) do
    cleanup_database
    @ts = FactoryGirl.create(:time_slot)
    @location_A = @ts.fitness_camp.location
    @location_B = FactoryGirl.create(:location, name: "location B")
    @user_at_B = FactoryGirl.create(:user, location_id: @location_B.id)
    @user_at_A = FactoryGirl.create(:user, location_id: @location_A.id)
    @second_user_at_A = FactoryGirl.create(:user, location_id: @location_A.id)
  end

  it "should reject a user that is not in the same location as the time_slot" do
    r = Registration.new(user: @user_at_B, time_slot: @ts)
    r.should_not be_valid
    r.errors.messages[:user].first.should == "A user and time slot must share the same location"
  end

  it "should be valid if the user belongs to location and is unique" do
    r = Registration.new(user: @user_at_A, time_slot: @ts)
    r.should be_valid    
  end

  it "should reject a user that tries to register twice" do
    r = Registration.new(user: @user_at_A, time_slot: @ts)
    r.save.should be true
    second_r = Registration.new(user: @user_at_A, time_slot: @ts)
    second_r.should_not be_valid
    second_r.errors.messages[:user].first.should == "A user can only register for one time_slot in a camp"
  end

  it "should reject a user that has registerd for two time slots in the same camp" do
    @ts_2_at_A = FactoryGirl.create(:time_slot, fitness_camp_id: @ts.fitness_camp.id)
    Registration.create(user: @user_at_A, time_slot: @ts_2_at_A)
    r = Registration.new(user: @user_at_A, time_slot: @ts)
    r.should_not be_valid
    r.errors.messages[:user].first.should == "A user can only register for one time_slot in a camp"
  end

  it "should not reject a user if two people sign up for a camp" do
    r1 = Registration.create(user: @user_at_A, time_slot_id: @ts.id)
    r2 = Registration.new(user: @second_user_at_A, time_slot_id: @ts.id)
    r2.should be_valid
  end
  
end