Add Spree::LocalizedNumber module

config/locales/en.yml

@@ -2361,3 +2361,5 @@ Please follow the instructions there to make your enterprise visible on the Open
         total: Total
         paid?: Paid?
         view: View
+    localized_number:
+      invalid_format: has an invalid format. Please enter a number.

lib/spree/localized_number.rb

@@ -0,0 +1,64 @@
+module Spree
+  module LocalizedNumber
+    # This method overwrites the attribute setters of a model
+    # to make them use the LocalizedNumber parsing method.
+    # It works with ActiveRecord "normal" attributes
+    # and Preference attributes.
+    # It also adds a validation on the input format.
+    # It accepts as arguments a variable number of attribute as symbols
+    def localize_number(*attributes)
+      validate :validate_localizable_number
+
+      attributes.each do |attribute|
+        setter = "#{attribute}="
+        old_setter = instance_method(setter) if table_exists? && !column_names.include?(attribute.to_s)
+
+        define_method(setter) do |number|
+          if Spree::LocalizedNumber.valid_localizable_number?(number)
+            number = Spree::LocalizedNumber.parse(number)
+          else
+            @invalid_localized_number ||= []
+            @invalid_localized_number << attribute
+            number = nil
+          end
+
+          if has_attribute?(attribute)
+            self[attribute] = number
+          else
+            old_setter.bind(self).call(number)
+          end
+        end
+
+        define_method(:validate_localizable_number) do
+          @invalid_localized_number.andand.each do |error_attribute|
+            errors.set(error_attribute, [I18n.t('spree.localized_number.invalid_format')])
+          end
+        end
+      end
+    end
+
+    def self.valid_localizable_number?(number)
+      return true unless number.is_a?(String) || number.respond_to?(:to_d)
+      return false if number =~ /[\.,]\d{2}[\.,]/
+      true
+    end
+
+    def self.parse(number)
+      return nil if number.blank?
+      return number.to_d unless number.is_a?(String)
+
+      number = number.gsub(/[^\d.,-]/, '') # Replace all Currency Symbols, Letters and -- from the string
+
+      if number =~ /^.*[\.,]\d{1}$/        # If string ends in a single digit (e.g. ,2)
+        number += "0"                      # make it ,20 in order for the result to be in "cents"
+      end
+
+      unless number =~ /^.*[\.,]\d{2}$/    # If does not end in ,00 / .00 then
+        number += "00"                     # add trailing 00 to turn it into cents
+      end
+
+      number = number.gsub(/[\.,]/, '')    # Replace all (.) and (,) so the string result becomes in "cents"
+      number.to_d / 100                    # Let to_decimal do the rest
+    end
+  end
+end