Vatcalc

A gem to calculate VAT of multiple products with differently VAT percentages.

Installation

Add this line to your application's Gemfile:

gem 'vatcalc'

And then execute:

$ bundle

Or install it yourself as:

$ gem install vatcalc

Include

Include Vatcalc::ActsAsBillElement in your models / Classes

class Product < ActiveRecord::Base
  include Vatcalc::ActsAsBillElement

  acts_as_bill_element(amount: price, vat_percentage: :my_vat_percentage_field, currency: "EUR", prefix: :bill)

  #you can pass the following key value pairs

  # amount: the price for the product [required]
  #     you can pass:
  #         symbol => for a method 
  #         lambda => ->(obj) {obj.price * 3}
  #         Float, Integer for a fix amount.
  #     NOTE: 
  #         if the value is an Integer it is assumed that the amount is given in cents.
  # 
  #
  # currency: 
  #     self-descriptive [optional] 
  #     standard value is the money default currency
  #     => https://github.com/RubyMoney/money
  #
  #     you can pass: 
  #         symbol => for a method 
  #         lambda => ->(obj) {obj.other_object.find_my_currency}
  #         String => "EUR", "USD"
  #
  #
  # vat_percentage: 
  #     the VAT percentage for the given product. [optional]
  #     This option will be ignored if you set the service option to true. +see below+
  #     Default is Vatcalc.vat_percentage => @see section "Configuration"
  #     you can pass: 
  #         symbol => for a method 
  #         lambda => ->(obj) {obj.find_my_currency}
  #         String => "EUR", "USD"
  #     NOTE: 
  #         if the value is between 1 and 100 the value will be divided by 100. 
  #         For example if you pass a value like 19 it is assumed that you mean 19% 
  #         if the value is between 0 and 100 the value won't be divided. 
  #
  # prefix: the prefix to call gross,vat,net,vat_splitted, and vat_percentage on your object.
  #        @see below.
  #
  #
 

Bill

Creating a new bill object

bill = Vatcalc::Bill.new(elements: [product1,product2,fee])

#NOTE: 
#    If you pass an Array of 2D arrays it is assumed that the first element in 2D Array is the object
#    and the second element is the quantity.
#    @example elements: 
#            [ 
#                [ product1, 2 ],
#                [ product2, 1 ] 
#            ]

#now you can call
bill.gross #=> #<Money fractional:15000 currency:EUR>
bill.vat #=>  #<Money fractional:1925 currency:EUR>
bill.net #=> #<Money fractional:13075 currency:EUR>

# if you only want to get amounts of the base.
bill.base.gross
...

# if you only want to get amounts of the services.
bill.services.gross
...



bill.vat_splitted #=> 
#
#   {
#       #<Vatcalc::VATPercentage vat_percentage:7%> => #<Money fractional:325 currency:EUR>,
#       #<Vatcalc::VATPercentage vat_percentage:19%> => #<Money fractional:1600 currency:EUR>
#   } 

# To get the vat rates 
# These vat rates are the net sums of the non-service elements grouped by vat_percentage and divided by total 
# non-service elements net amount

bill.vat_rates # => 
#   {
#       #<Vatcalc::VATPercentage vat_percentage:19%>=>0.6424,
#       #<Vatcalc::VATPercentage vat_percentage:7%>=>0.3576,
#   }

## NOTE: Each service Element will be taxed by these rates.




bill.each do |obj, quantity, gross, vat, net|
    # NOTE: gross, vat, net are already multiplied by quantity
    # do stuff .. 
end

Configuration

gem 'vatcalc'

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/vatcalc. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The gem is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the Vatcalc project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.