json_annotation

Defines the annotations used by json_serializable to create code for JSON serialization and deserialization.

See the example to understand how to configure your package.

Features and bugs

Please file feature requests and bugs at the issue tracker.

4.12.0

• Add JsonKey.explicitJsonNullWhenNonNullField for PATCH-style tri-state JSON fields (omit key vs explicit null vs value).

4.11.0

• Add JsonSerializable.dateTimeUtc configuration option. (#1371)

4.10.0

• Support JsonKey annotation on constructor parameters.
• Add JsonSerializable(createJsonSchema: true). (Huge thanks to Chris Sells for the PR!)
• Require meta: ^1.16.0
• Require sdk: ^3.9.0

4.9.0

• Require Dart 3.0
• Add JsonSerializable(createJsonKeys: true). (#1401)

4.8.1

• Require Dart 2.19
• Add topics.

4.8.0

• DEPRECATED JsonKey.ignore. Replaced by...
• Added JsonKey.includeFromJson and JsonKey.includeToJson to allow fine-grained control of if a field is encoded/decoded.
• Added JsonSerializable.createPerFieldToJson which allows generating a _$ModelPerFieldToJson, enabling partial encoding of a model.
• Update JsonKey documentation to align with new features in package:json_serializable.
• Require Dart SDK >=2.18.0.

4.7.0

• Added JsonEnum.valueField which allows specifying a field in an "enhanced enum" to use for serialization instead of specifying each value individually with JsonValue.
• Require Dart SDK 2.17

4.6.0

• Added JsonSerializable(createFieldMap: true). (#1164)
• Added JsonSerializable(converters: <JsonConverter>[]) (#1072)

4.5.0

• Added FieldRename.screamingSnake.

4.4.0

• Added JsonKey.readValue.
• Non-breaking updates to checkedCreate and checkedConvert to support JsonKey.readValue.
• Improved toString in included exceptions.

4.3.0

• Changed the type of JsonKey.unknownEnumValue from Object? to Enum?. Assuming this feature has been used correctly, it shouldn't be a breaking change.
• Changed the type of the $enumDecodeNullable parameter unknownValue from Object? to Enum?.

4.2.0

• Added JsonSerializable.constructor field to allow specifying an alternative constructor to invoke when creating a fromJson helper.
• Added JsonEnum for annotating enum types.
• Added $enumDecodeNullable and $enumDecode helpers to minimize generated code.
• Added const JsonKey.nullForUndefinedEnumValue for use in JsonKey.unknownEnumValue when you want to use null for an unknown value.
• Require Dart SDK >=2.14.0.

4.1.0

• Added a const constructor to JsonConverter.
• Added $checkedCreate helper that will be used by package:json_serializable v5+ and replaces both $checkedNew and $checkedConvert.
• Annotate annotations with the supported target types, to minimize incorrect usage.

4.0.1

• Fix a potential error with checked: true when ArgumentError.message is null.
• Updated JsonSerializable.fromJson to handle null values.
• Deprecate JsonSerializable defaults and withDefaults().

4.0.0

• Support null safety.
• Requires Dart 2.12.
• Updated $checkedConvert helper to support null-safety.
• Removed the nullable field on JsonKey – the constructor entry still exists, but it's marked @Deprecated. The nullability of a field is now determined by the Dart type system.

3.1.1

• Avoid null values for CheckedFromJsonException.message by using toString() with unrecognized error types.
• Added a helpful UnrecognizedKeysException.toString().
• Fixed doc comments for JsonSerializable.genericArgumentFactories.

3.1.0

• Added JsonSerializable.genericArgumentFactories field.
• Require at least Dart 2.7.0.

3.0.1

• Require at least Dart 2.6.0.
• Fix lint that was affecting pub.dev score.

3.0.0

• BREAKING Removed JsonSerializable.useWrappers and associated $-prefixed helpers.
• BREAKING Removed JsonSerializable.generateToJsonFunction.
• BREAKING Removed encodeEmptyCollection from JsonSerializable and JsonKey.
• Added JsonSerializable.ignoreUnannotated.
• Added JsonKey.unknownEnumValue.
• Require at least Dart 2.3.0.

2.4.0

• Deprecate members that will be removed in json_annotation 3.0.0 and that are not supported in json_serializable 3.0.0.
  • JsonSerializable.useWrappers and associated $-prefixed helpers
  • JsonSerializable.generateToJsonFunction,
  • encodeEmptyCollection from JsonSerializable and JsonKey.

2.3.0

• Added pascal as an additional fieldRename option.
• Require at least Dart 2.2.0.

2.2.0

• Add an optional (named) badKey parameter and field to CheckedFromJsonException.

2.1.0

• Require at least Dart 2.1.1.

• Added to encodeEmptyCollection to JsonKey and JsonSerializable.

• JsonSerializable.fromJson now throws CheckedFromJsonException on errors. This is potentially a breaking change.

• Added a more helpful toString to CheckedFromJsonException.

2.0.0

• Potentially Breaking JsonSerializable no longer sets default values for fields when constructor arguments are unset or null. This is not likely an issue for developers using this class as an annotation with a compatible version of package:json_serializable, but it may cause issues if class is used in other contexts.

• Support all build.yaml configuration options on classes by adding a number of fields to JsonSerializable: anyMap, checked, explicitToJson, generateToJsonFunction, and useWrappers.

1.2.0

• Added JsonConverter class to support custom conversion of types.

1.1.0

• Added the fieldRename option to JsonSerializable and the associated FieldRename enum.

1.0.0

• Added JsonValue class for annotating enum fields with a custom serialization value.

• Removed $checkAllowedKeys, $enumDecode and $enumDecodeNullable which are no longer needed by the latest release of package:json_serializable.

0.2.9+1

• Support the Dart 2.0 stable release.

0.2.9

• When FormatException is caught in "checked mode", use the message property when creating CheckedFromJsonException.

0.2.8

• Added $checkKeys helper function and deprecated $checkAllowedKeys. Upgrading to the latest json_serializable and re-running your build will eliminate any @deprecated hints you see.

• Added BadKeyException exception which is the abstract super class for MissingRequiredKeysException, UnrecognizedKeysException, and DisallowedNullValueException.

• Added JsonKey.required field and an associated MissingRequiredKeysException that is thrown when required fields don't have corresponding keys in a source JSON map.

• Added JsonKey.disallowNullValue field and an associated DisallowedNullValueException that is thrown when corresponding keys exist in a source JSON map, but their values are null.

• Updated documentation of JsonSerializable.createToJson to include details of the new generate_to_json_function configuration option.

0.2.7+1

• Small improvement to UnrecognizedKeysException.message output and documentation comments.

0.2.7

• Added JsonSerializable.disallowUnrecognizedKeys.
  • Added a helper function to support this option. This function starts with a $ and should only be referenced by generated code. It is not meant for direct use.
  • Added UnrecognizedKeysException for reporting errors.

0.2.6

• CheckedFromJsonException

  • Added a public constructor to support hand-written JSON decoding logic.
  • The message property is now String (instead of Object).

• Added JsonKey.defaultValue.

• Added helpers for deserialization of enum values. These functions starting with $ are referenced by generated code. They are not meant for direct use.

0.2.5

• Added CheckedFromJsonException which is thrown by code generated when checked is enabled in json_serializable.

• Added functions to support the checked generation option. These functions starting with $ are referenced by generated code. They are not meant for direct use.

0.2.4

• Added fromJson and toJson fields to JsonKey class.

0.2.3

• Added ignore field to JsonKey class annotation

0.2.2

• Added a helper class – $JsonMapWrapper – and helper functions – $wrapMap, $wrapMapHandleNull, $wrapList, and $wrapListHandleNull – to support the useWrappers option added to JsonSerializableGenerator in v0.3.0 of package:json_serializable.

0.2.1

• JsonSerializable class annotation
  • Added nullable field.
  • Fixed doc comment.

0.2.0

• Moved annotation classes for JsonSerializable and JsonLiteral.