registerEnum<T> static method

void registerEnum<T>(List<T> values, { String? jsonEnumCode, EnumFormat enumFormat = EnumFormat.string, Enum? unknownEnumValue, })

Registers a new Enum type.

You can register standard enums or 'enhanced enums' handling (new in dart 2.17 release) using the JsonizableEnum interface. If the registered enum implements JsonizableEnum then the enumFormat parameter is ignored. The unknownEnumValue is used during decoding in case of an unrecognized value. This can happen if an old json holds a removed enum. unknownEnumValue is not applicable to EnumFormat.indexOf!

Implementation

static void registerEnum<T>(List<T> values,
    {String? jsonEnumCode,
    EnumFormat enumFormat = EnumFormat.string,
    Enum? unknownEnumValue}) {
  // Parameters check
  if (enumFormat == EnumFormat.indexOf && unknownEnumValue != null) {
    throw JsonizeException("registerEnum",
        "EnumFormat.indexOf does not support 'unknownEnumValue' parameter!");
  }
  // Enum types
  Type type = values.first.runtimeType;
  jsonEnumCode = jsonEnumCode ?? "e#$type";
  // unknownEnumValue handling function
  T orElse(o) => unknownEnumValue != null
      ? unknownEnumValue as T
      : (throw JsonizeException(
          "Enum decoding", "'$o' is not a defined value of '$type'"));
  // Register the enum type
  if (values.first is JsonizableEnum) {
    Jsonize.registerType(
        type,
        jsonEnumCode,
        (o) => o.jsonValue,
        (o) => values.singleWhere((i) => o == (i as JsonizableEnum).jsonValue,
            orElse: () => orElse(o)));
  } else if (enumFormat == EnumFormat.string) {
    Jsonize.registerType(
        type,
        jsonEnumCode,
        (o) => _enumToString(o),
        (o) => values.singleWhere((i) => o == _enumToString(i),
            orElse: () => orElse(o)));
  } else {
    Jsonize.registerType(
        type, jsonEnumCode, (o) => values.indexOf(o), (o) => values[o]);
  }
}