Decimals and commas when entering a number into a Ruby on Rails form

Question

What\'s the best Ruby/Rails way to allow users to use decimals or commas when entering a number into a form? In other words, I would like the user be able to enter 2,000.99

Answer 1

I have written following code in my project. This solved all of my problems.

config/initializers/decimal_with_comma.rb

# frozen_string_literal: true

module ActiveRecord
  module Type
    class Decimal
      private

      alias_method :cast_value_without_comma_separator, :cast_value

      def cast_value(value)
        value = value.gsub(',', '') if value.is_a?(::String)
        cast_value_without_comma_separator(value)
      end
    end

    class Float
      private

      alias_method :cast_value_without_comma_separator, :cast_value

      def cast_value(value)
        value = value.gsub(',', '') if value.is_a?(::String)
        cast_value_without_comma_separator(value)
      end
    end

    class Integer
      private

      alias_method :cast_value_without_comma_separator, :cast_value

      def cast_value(value)
        value = value.gsub(',', '') if value.is_a?(::String)
        cast_value_without_comma_separator(value)
      end
    end
  end
end

module ActiveModel
  module Validations
    class NumericalityValidator
      protected

        def parse_raw_value_as_a_number(raw_value)
          raw_value = raw_value.gsub(',', '') if raw_value.is_a?(::String)
          Kernel.Float(raw_value) if raw_value !~ /\A0[xX]/
        end
    end
  end
end

Answer 2

Take a look at the i18n_alchemy gem for date & number parsing and localization.

I18nAlchemy aims to handle date, time and number parsing, based on current I18n locale format. The main idea is to have ORMs, such as ActiveRecord for now, to automatically accept dates/numbers given in the current locale format, and return these values localized as well.