https://github.com/RubyMoney/money
Tip revision: 50dc48e85818e15ca353561201a8e35333e48d00 authored by Shane Emmons on 01 November 2011, 15:07:58 UTC
version bump to 4.0.0
version bump to 4.0.0
Tip revision: 50dc48e
currency.rb
# encoding: utf-8
require "json"
class Money
# Represents a specific currency unit.
class Currency
include Comparable
extend CurrencyLoader
# Thrown when an unknown currency is requested.
class UnknownCurrency < StandardError; end
# List of known currencies.
#
# == monetary unit
# The standard unit of value of a currency, as the dollar in the United States or the peso in Mexico.
# http://www.answers.com/topic/monetary-unit
# == fractional monetary unit, subunit
# A monetary unit that is valued at a fraction (usually one hundredth) of the basic monetary unit
# http://www.answers.com/topic/fractional-monetary-unit-subunit
#
# See http://en.wikipedia.org/wiki/List_of_circulating_currencies and
# http://search.cpan.org/~tnguyen/Locale-Currency-Format-1.28/Format.pm
TABLE = load_currencies
# The symbol used to identify the currency, usually the lowercase
# +iso_code+ attribute.
#
# @return [Symbol]
attr_reader :id
# A numerical value you can use to sort/group the currency list.
#
# @return [Integer]
attr_reader :priority
# The international 3-letter code as defined by the ISO 4217 standard.
#
# @return [String]
attr_reader :iso_code
#
# The international 3-numeric code as defined by the ISO 4217 standard.
#
# @return [String]
attr_reader :iso_numeric
# The currency name.
#
# @return [String]
attr_reader :name
# The currency symbol (UTF-8 encoded).
#
# @return [String]
attr_reader :symbol
# The html entity for the currency symbol
#
# @return [String]
attr_reader :html_entity
# The name of the fractional monetary unit.
#
# @return [String]
attr_reader :subunit
# The proportion between the unit and the subunit
#
# @return [Integer]
attr_reader :subunit_to_unit
# The decimal mark, or character used to separate the whole unit from the subunit.
#
# @return [String]
attr_reader :decimal_mark
alias :separator :decimal_mark
# The character used to separate thousands grouping of the whole unit.
#
# @return [String]
attr_reader :thousands_separator
alias :delimiter :thousands_separator
# Should the currency symbol precede the amount, or should it come after?
#
# @return [boolean]
attr_reader :symbol_first
def symbol_first?
!!@symbol_first
end
# The number of decimal places needed.
#
# @return [Integer]
def decimal_places
if subunit_to_unit == 1
0
elsif subunit_to_unit % 10 == 0
Math.log10(subunit_to_unit).to_s.to_i
else
Math.log10(subunit_to_unit).to_s.to_i+1
end
end
# Create a new +Currency+ object.
#
# @param [String, Symbol, #to_s] id Used to look into +TABLE+ and retrieve
# the applicable attributes.
#
# @return [Money::Currency]
#
# @example
# Money::Currency.new(:usd) #=> #<Money::Currency id: usd ...>
def initialize(id)
@id = id.to_s.downcase.to_sym
data = TABLE[@id] || raise(UnknownCurrency, "Unknown currency `#{id}'")
data.each_pair do |key, value|
instance_variable_set(:"@#{key}", value)
end
end
# Compares +self+ with +other_currency+ against the value of +priority+
# attribute.
#
# @param [Money::Currency] other_currency The currency to compare to.
#
# @return [-1,0,1] -1 if less than, 0 is equal to, 1 if greater than
#
# @example
# c1 = Money::Currency.new(:usd)
# c2 = Money::Currency.new(:jpy)
# c1 <=> c2 #=> 1
# c2 <=> c1 #=> -1
# c1 <=> c1 #=> 0
def <=>(other_currency)
self.priority <=> other_currency.priority
end
# Compares +self+ with +other_currency+ and returns +true+ if the are the
# same or if their +id+ attributes match.
#
# @param [Money::Currency] other_currency The currency to compare to.
#
# @return [Boolean]
#
# @example
# c1 = Money::Currency.new(:usd)
# c2 = Money::Currency.new(:jpy)
# c1 == c1 #=> true
# c1 == c2 #=> false
def ==(other_currency)
self.equal?(other_currency) ||
self.id == other_currency.id
end
# Compares +self+ with +other_currency+ and returns +true+ if the are the
# same or if their +id+ attributes match.
#
# @param [Money::Currency] other_currency The currency to compare to.
#
# @return [Boolean]
#
# @example
# c1 = Money::Currency.new(:usd)
# c2 = Money::Currency.new(:jpy)
# c1.eql? c1 #=> true
# c1.eql? c2 #=> false
def eql?(other_currency)
self == other_currency
end
# Returns a Fixnum hash value based on the +id+ attribute in order to use
# functions like & (intersection), group_by, etc.
#
# @return [Fixnum]
#
# @example
# Money::Currency.new(:usd).hash #=> 428936
def hash
id.hash
end
# Returns a string representation corresponding to the upcase +id+
# attribute.
#
# -–
# DEV: id.to_s.upcase corresponds to iso_code but don't use ISO_CODE for consistency.
#
# @return [String]
#
# @example
# Money::Currency.new(:usd).to_s #=> "USD"
# Money::Currency.new(:eur).to_s #=> "EUR"
def to_s
id.to_s.upcase
end
# Conversation to +self+.
#
# @return [self]
def to_currency
self
end
# Returns a human readable representation.
#
# @return [String]
#
# @example
# Money::Currency.new(:usd) #=> #<Currency id: usd ...>
def inspect
"#<#{self.class.name} id: #{id}, priority: #{priority}, symbol_first: #{symbol_first}, thousands_separator: #{thousands_separator}, html_entity: #{html_entity}, decimal_mark: #{decimal_mark}, name: #{name}, symbol: #{symbol}, subunit_to_unit: #{subunit_to_unit}, iso_code: #{iso_code}, iso_numeric: #{iso_numeric}, subunit: #{subunit}>"
end
# Class Methods
class << self
# Lookup a currency with given +id+ an returns a +Currency+ instance on
# success, +nil+ otherwise.
#
# @param [String, Symbol, #to_s] id Used to look into +TABLE+ and
# retrieve the applicable attributes.
#
# @return [Money::Currency]
#
# @example
# Money::Currency.find(:eur) #=> #<Money::Currency id: eur ...>
# Money::Currency.find(:foo) #=> nil
def find(id)
id = id.to_s.downcase.to_sym
new(id) if self::TABLE[id]
end
# Wraps the object in a +Currency+ unless it's already a +Currency+
# object.
#
# @param [Object] object The object to attempt and wrap as a +Currency+
# object.
#
# @return [Money::Currency]
#
# @example
# c1 = Money::Currency.new(:usd)
# Money::Currency.wrap(nil) #=> nil
# Money::Currency.wrap(c1) #=> #<Money::Currency id: usd ...>
# Money::Currency.wrap("usd") #=> #<Money::Currency id: usd ...>
def wrap(object)
if object.nil?
nil
elsif object.is_a?(Currency)
object
else
Currency.new(object)
end
end
end
end
end