所需文件
- active_model/type/helpers
- active_model/type/serialize_cast_value
- active_model/type/value
- active_model/type/big_integer
- active_model/type/binary
- active_model/type/boolean
- active_model/type/date
- active_model/type/date_time
- active_model/type/decimal
- active_model/type/float
- active_model/type/immutable_string
- active_model/type/integer
- active_model/type/string
- active_model/type/time
- active_model/type/registry
命名空间
- 模块 ActiveModel
- 模块 ActiveModel::Type