Current Supported Types

Ciris has support for many standard library types, and integrates with libraries like enumeratum, refined, spire, and squants, to support even more types. If you’re trying to decode a standard library type, it’s likely that it should be supported by Ciris, so please file an issue or, even better, submit a pull request. The same applies if you’re trying to integrate with a library for which Ciris does not already provide a module.

The following basic types have support for decoding from String in the core module.

  • Boolean, Byte, Char, Double, Float, Int, Long, Short, and String.
    • Double and Float decoders also support percent format ending with %.
    • Booleans can be decoded from true/false, yes/no, and on/off.
  • File.
  • java.math: BigInteger and BigDecimal.
  • InetAddress, URI, and URL.
  • java.nio.charset: Charset.
  • java.nio.file: Path.
  • java.time.chrono: Chronology, HijrahEra, IsoEra, JapaneseEra, MinguoEra, ThaiBuddhistEra.
  • java.time.format: DateTimeFormatter, FormatStyle, ResolverStyle, SignStyle, and TextStyle.
  • java.time: DayOfWeek, Duration, Instant, LocalDate, LocalDateTime, LocalTime, Month, MonthDay, OffsetDateTime, OffsetTime, Period, Year, YearMonth, ZonedDateTime, ZoneId, and ZoneOffset. Some of these decoders can optionally be configured, see the configurable decoders section.
  • java.util.regex: Pattern.
  • java.util: UUID.
  • scala.concurrent.duration: Duration and FiniteDuration.
  • scala.math: BigInt and BigDecimal.
  • scala.util.matching: Regex.

The following composite types are supported in the core module.

  • Option for values which are not required to be present. See the usage basics section for an example.
  • Secret for avoiding logging secret configuration values. See logging configurations for more details.

Modules provide support for additional types, please refer to modules overview for more information.
For an explanation of how you can write decoders to support new types, refer to supporting new types.

Configurable Decoders

Some java.time decoders can optionally be configured to use a different parsing format. Unless configured, decoders will rely on the default parsing behaviour and format. These decoders look for an implicit DateTimeFormatter, so to override the behaviour, simply provide one in scope.

import ciris.{ConfigEntry, ConfigKeyType}
// import ciris.{ConfigEntry, ConfigKeyType}

import java.time.format.DateTimeFormatter
// import java.time.format.DateTimeFormatter

import java.time.LocalDate
// import java.time.LocalDate

val entry = ConfigEntry("key", ConfigKeyType("key type"), Right("20180307"))
// entry: ciris.ConfigEntry[ciris.api.Id,String,String,String] = ConfigEntry(key, ConfigKeyType(key type))

implicit val format: DateTimeFormatter =
// format: java.time.format.DateTimeFormatter = Value(YearOfEra,4,19,EXCEEDS_PAD)Value(MonthOfYear,2)Value(DayOfMonth,2)

// res0: ciris.ConfigEntry[ciris.api.Id,String,String,java.time.LocalDate] = ConfigEntry(key, ConfigKeyType(key type))

Note that the implicit DateTimeFormatter format will be used for all configurable java.time decoders in its scope. If you’re decoding multiple java.time types, you might need to limit the scope of the implicit format. Alternatively, you can also create the decoder manually by specifying the format to use.

import ciris.ConfigDecoder
// import ciris.ConfigDecoder

implicit val localDateDecoder: ConfigDecoder[String, LocalDate] =
// localDateDecoder: ciris.ConfigDecoder[String,java.time.LocalDate] = ConfigDecoder$1424197009

// res1: ciris.ConfigEntry[ciris.api.Id,String,String,java.time.LocalDate] = ConfigEntry(key, ConfigKeyType(key type))