1 files changed, 46 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/number_helper/number_to_currency_converter.rb b/activesupport/lib/active_support/number_helper/number_to_currency_converter.rb
new file mode 100644
index 0000000000..9ae27a896a
--- /dev/null
+++ b/activesupport/lib/active_support/number_helper/number_to_currency_converter.rb
@@ -0,0 +1,46 @@
+module ActiveSupport
+  module NumberHelper
+    class NumberToCurrencyConverter < NumberConverter # :nodoc:
+      self.namespace = :currency
+
+      def convert
+        number = self.number.to_s.strip
+        format = options[:format]
+
+        if is_negative?(number)
+          format = options[:negative_format]
+          number = absolute_value(number)
+        end
+
+        rounded_number = NumberToRoundedConverter.convert(number, options)
+        format.gsub('%n', rounded_number).gsub('%u', options[:unit])
+      end
+
+      private
+
+        def is_negative?(number)
+          number.to_f.phase != 0
+        end
+
+        def absolute_value(number)
+          number.respond_to?("abs") ? number.abs : number.sub(/\A-/, '')
+        end
+
+        def options
+          @options ||= begin
+            defaults = default_format_options.merge(i18n_opts)
+            # Override negative format if format options is given
+            defaults[:negative_format] = "-#{opts[:format]}" if opts[:format]
+            defaults.merge!(opts)
+          end
+        end
+
+        def i18n_opts
+          # Set International negative format if not exists
+          i18n = i18n_format_options
+          i18n[:negative_format] ||= "-#{i18n[:format]}" if i18n[:format]
+          i18n
+        end
+    end
+  end
+end