# This module extends a model's decimal column with a virtual attributes to address Rails lack of
# internationalization support of form helpers. This modules provides a setter and a getter method
# that format numbers according to the current app's locale (google "I18n.locale" for more info).
#
# Usage:
#
# YourModel < < ActiveRecord::Base
# include FormattedDecimal
# formatted_decimal :total, :sub_total
# ...
#
# Then in your views use the formatted_total and formatted_sub_total attributes instead:
#
# <%= text_field :invoice, :formatted_total, :size => 15 %>
#
# Expects the locale file (app/config/locale/it.yml) to define a number format
# it:
# number:
# format:
# separator: ","
# delimiter: "'"
# precision: 2
module FormattedDecimal
def self.included(base)
base.extend(ClassMethods)
end
module ClassMethods
# Define a new class method that adds the getter and setter methods.
def formatted_decimal(*args)
args.is_a?(Array) ? symbols = args : symbols = [args]
symbols.each do |symbol|
# getter
method = "formatted_#{symbol.to_s}"
self.send(:define_method, method) do
formatNum(self.send(symbol))
end
# setter
self.send(:define_method, method + '=') do |val|
self.send("#{symbol}=", parseNum(val))
end
end
end
end
protected
# Returns the default number format from the current I18n locale.
def getNumFormat
begin
I18n.translate(:'number.format', :locale => I18n.locale, :raise => true)
rescue
{ :precision => 3, :separator => ".", :delimiter => "" }
end
end
# Parses a formatted number into a BigDecimal.
def parseNum(num)
format = getNumFormat
begin
parts = num.to_s.split(format[:separator])
parts[0].gsub!(format[:delimiter], '')
parts[1] = parts[1][0,format[:precision]] if format[:precision]
parts.join('.').to_d
rescue
num
end
end
# Prints a number to a string, formatted using the correct locale.
def formatNum(num)
format = getNumFormat
begin
parts = num.to_s.split('.')
parts[0].gsub!(/(\d)(?=(\d\d\d)+(?!\d))/, "\\1#{format[:delimiter]}")
parts[1] = parts[1][0,format[:precision]] if format[:precision]
parts.join(format[:separator])
rescue
num
end
end
end
