This library aids one in handling money and different currencies. Features:
Provides a Money class which encapsulates all information about an certain amount of money, such as its value and its currency.
Represents monetary values as integers, in cents. This avoids floating point rounding errors.
Provides APIs for exchanging money from one currency to another.
Has the ability to parse a money string into a Money object.
Provides ActiveRecord “has_money” method.
Autofetch rates from ECB
gem sources -a http://gems.github.com gem install <this-fork>-money
require 'money' # 10.00 USD money = Money.new(1000, "USD") money.cents # => 1000 money.currency # => "USD" money.format # => "$10.00" Money.new(880088, "EUR").format # => €8,800.88 Money.new(-8000).format(:no_cents => true) # => $-80 Money.new(1000, "USD") == Money.new(1000, "USD") # => true Money.new(1000, "USD") == Money.new( 100, "USD") # => false Money.new(1000, "USD") == Money.new(1000, "EUR") # => false
You can use round_to_coin when you don't have currency with coins for cents. E.g. if the smallest coin is 0.50, then
Money.new(1448, 'CZK').round_to_coin(50).to_s # => "14.50"
Exchanging money is performed through an exchange bank object. The default exchange bank object requires one to manually specify the exchange rate. Here's an example of how it works:
Money.add_rate("CAD", 0.803115) Money.add_rate("USD", 1.24515) Money.us_dollar(100_00).exchange_to("CAD") # => Money.new(15504, "CAD") Money.ca_dollar(100_00).exchange_to("USD") # => Money.new(6450, "USD")
Money.us_dollar(100).as_cad # => Money.new(155, "CAD") Money.ca_dollar(100).as_usd # => Money.new(64, "USD")
Comparison and arithmetic operations work as expected:
Money.new(1000, "USD") <=> Money.new(900, "USD") # => 1; 9.00 USD is smaller Money.new(1000, "EUR") + Money.new(10, "EUR") == Money.new(1010, "EUR") Money.add_rate("EUR", 0.5) Money.new(1000, "EUR") + Money.new(1000, "USD") == Money.new(1500, "EUR")
Fetch the exchange rates published by the European Bank
Money.default_bank.fetch_rates # Fetch the rates Money.default_bank.auto_fetch 3600 # Fetch the rates every hour Money.default_bank.stop_fetch # Stop auto-fetch
There is nothing stopping you from creating bank objects which scrapes www.xe.com for the current rates or just returns rand(2):
Money.default_bank = ExchangeBankWhichScrapesXeDotCom.new
`new` or `to_money` ?
If you already have a value in integer/float or a string which ruby can parse with `to_i`, use new. It'll avoid the string parser, which is resource intensive.
Money defaults to USD as its currency. This can be overwritten using:
Money.default_currency = "CAD"
If you use Rails, then environment.rb is a very good place to put this.
By default, Money won't fetch the rates automatically, you need to call: @some_bank.fetch_rates
If you have your bank default rates configured, it'll fetch all possible rates from it, if you don't, It'll fetch all rates to and from your default_currency.
Money uses the ECB XML Feed. (ecb.int)
Ruby on Rails
Use the has_money method to embed the money object in your models. The following example requires a price_cents and a price_currency fields on the database.
require.gem 'bobek-money', :lib => 'money'
class Product < ActiveRecord::Base belongs_to :product has_money :price validates_numericality_of :price_cents, :greater_than => 0 end
create_table :products do |t| t.integer :price_cents t.string :price_currency end
Check out meiaduzia.com.br/cuducos2/priceformat for a nice mask for webapp's textfields.
Orinally developed by:
Forked from: github.com/FooBarWidget/money
RDoc API: money.rubyforge.org
This branch is part of: