Date compare, line 17

bill.rb

class Bill < ActiveRecord::Base
  belongs_to :customer
  attr_accessible :amount, :date_due, :paid
  validates :amount, presence: true
  validates :date_due, presence: true

  before_create :default_values
  before_save :update_date_paid
  after_save :update_history

  def default_values
    self.paid ||= false
    true # Don't prevent save by returning false.
  end

  scope :pending, where(:paid => false)
  scope :overdue, pending.where('date_due < ?', Date.today)

  def self.find_paid
    where(:paid => true)
  end

  def update_date_paid
    if self.paid && self.date_paid.nil?
      write_attribute(:date_paid, Time.now)
    elsif !self.paid && !self.date_paid.nil?
      write_attribute(:date_paid, nil)
    end
  end

  def update_history
    History.add_entry('bills', self.id, self.previous_changes)
  end
end
# == Schema Information
#
# Table name: bills
#
#  id          :integer         not null, primary key
#  customer_id :integer
#  amount      :integer
#  date_paid   :datetime
#  paid        :boolean
#  created_at  :datetime        not null
#  updated_at  :datetime        not null
#  date_due    :date
#

index.erb.html

# app/views/customers/index.erb.html

<h1>Listing customers</h1>

<table class="table table-striped sortable">
  <thead>
    <tr>
      <th>Name</th>
      <th>Address</th>
      <th>County</th>
      <th>State</th>
      <th>Zip</th>
      <th></th>
      <th></th>
    </tr>
  </thead>

<% @customers.each do |customer| %>
  <tr>
    <td><%= link_to customer.name, customer %>
      <% if !customer.active %><span class="label">Inactive</span><% end %>
      <% if customer.bills.overdue.any? %><span class="label label-important">Overdue</span><% end %>
    </td>
    <td><%= customer.address %></td>
    <td><%= customer.county %></td>
    <td><%= customer.state %></td>
    <td><%= customer.zip %></td>
    <td><%= link_to 'Edit', edit_customer_path(customer) %></td>
    <td><%= link_to 'Destroy', customer, confirm: 'Are you sure?', method: :delete %></td>
  </tr>
<% end %>
</table>

<%= link_to 'New Customer', new_customer_path, class: 'btn' %>