Rails flash improvements

flash_hash.rb

module ActionDispatch
  class Flash
    class FlashHash
      # Returns a hash that includes everything but the given keys.
      #   hash = { a: true, b: false, c: nil}
      #   hash.except(:c) # => { a: true, b: false}
      #   hash # => { a: true, b: false, c: nil}
      #
      # This is useful for limiting a set of parameters to everything but a few known toggles:
      #   @person.update(params[:person].except(:admin))
      def except(*keys)
        HashWithIndifferentAccess.new(@flashes).dup.except!(*keys)
      end

      # Replaces the hash without the given keys.
      #   hash = { a: true, b: false, c: nil}
      #   hash.except!(:c) # => { a: true, b: false}
      #   hash # => { a: true, b: false }
      def except!(*keys)
        keys.each { |key| delete(key) }
        self
      end
    end
  end
end