ack_annotations

ack_annotations provides the @AckInfer() schema-first and @AckModel() class-first annotations used by ack_generator. Deprecated @AckType() is retained for Ack 1.1 extension-type compatibility.

Installation

dependencies:
  ack: ^1.2.0
  ack_annotations: ^1.2.0

dev_dependencies:
  ack_generator: ^1.2.0
  build_runner: ^2.4.0

Usage

Annotate a top-level Ack schema variable or getter and run build_runner:

import 'package:ack/ack.dart';
import 'package:ack_annotations/ack_annotations.dart';

part 'user.ack.dart';
part 'user.ack.g.dart';

@AckInfer()
final userSchema = Ack.object({
  'name': Ack.string(),
  'email': Ack.string().email(),
});

ack_generator emits an immutable User class with typed fields, an unchecked constructor, parsing helpers, JSON methods, generated copyWith, deep collection-aware equality, and a public $ack adapter. The Ack part owns those declarations; json_serializable writes the structural field-mapping helpers into user.ack.g.dart. Ack-only apps do not add JSON packages for generated models. The annotation package requires Dart 3.9.

Generate the model with:

dart run build_runner build

For class-first generation, keep the class in source and apply its generated mixin:

@AckModel()
final class Account with _$AccountAck {
  const Account({required this.name});

  @MinLength(2)
  final String name;

  static final fromJson = AccountSchema.fromJson;
}

This generates the public AccountSchema facade plus validated toJson, safeToJson, copyWith, equality, and toString implementations.

Custom names

Use name to set the exact generated class name:

@AckInfer(name: 'Password')
final passwordSchema = Ack.string().minLength(8);

This generates Password. Names must be unchanged UpperCamelCase identifiers; an intentional Type suffix is kept exactly.

Supported targets

• Top-level schema variables
• Top-level schema getters

@AckInfer() is not supported on classes or instance members.

@AckModel() targets a public, constructable final class with final stored fields and derives an Ack codec schema from its constructor-backed fields. Annotated sealed union bases remain supported; each concrete branch must be final. Instantiable models apply the generated _$ClassAck mixin. The public <ClassName>Schema facade exposes typed schema and raw wireSchema; schemaName: overrides the exact facade class name and must be UpperCamelCase.

Unknown properties use unknownProperties: AckUnknownPropertyPolicy.<policy>. Use discard only for tolerant, read-only consumers; models that round-trip unknown keys use capture and may select their map field with captureField. @AckField can override schema and/or AckFieldPresence. See the Model Code Generation guide.