to_bool2.rb

def to_boolean(value, nil_value = false)
  compare_value = value.class == String ? value.downcase : value
  case compare_value
    when "no","false",false, "0", 0
      false
    when "yes","true",true, "1", 1
      true
    when nil
      nil_value
    else
      !!compare_value
    end
end