auto_entity 1.0.1

Lightweight Dart/Flutter code generator for JSON serialization and model-entity mapping.

Auto Entity

A lightweight Flutter/Dart code generator for:

✅ JSON fromJson / toJson generation (like json_serializable)
✅ Seamless Model ⇄ Entity mapping
✅ Field renaming for JSON and Entity layers
✅ Built‑in DateTime handling (nullable + lists)
✅ Custom converters via simple expressions

---

Features

✅ JSON serialization

Automatically generates:

factory Model.fromJson(Map<String, dynamic> json)
Map<String, dynamic> toJson()

Supports:

• DateTime.parse() / .toIso8601String()
• Nullable fields
• List<T> and List<DateTime>
• Standard Dart types

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✅ Entity mapping

Also generates:

extension _$ModelEntityExtension on Model {
  Entity toEntity();
  static Model fromEntity(Entity entity);
}

---

✅ Field control with @AutoField

Customize each field:

• JSON key → name
• Entity field name → entityName
• Conversion expressions → toEntity, fromEntity
• Skip fields → ignore: true

---

Installation

Add to your pubspec.yaml:

dependencies:
  auto_entity: ^1.0.0

dev_dependencies:
  build_runner: ^2.10.4

---

Usage

1. Define your Entity

class UserEntity {
  final String id;
  final String name;
  final DateTime createdAt;

  const UserEntity({
    required this.id,
    required this.name,
    required this.createdAt,
  });
}

---

2. Define your Model

import 'package:auto_entity/auto_entity.dart';

part 'user_model.auto_entity.g.dart';

@AutoEntity(entity: UserEntity)
class UserModel {
  @AutoField(name: 'user_id')
  final String? id;

  @AutoField(name: 'user_name')
  final String? name;

  @AutoField(
    name: 'created_at',
    toEntity: 'value == null ? null : DateTime.parse(value!)',
    fromEntity: 'value?.toIso8601String()',
  )
  final String? createdAt;

  @AutoField(name: 'displayName', entityName: 'displayName')
  final String? display;

  const UserModel({this.id, this.name, this.createdAt, this.display});

  factory UserModel.fromJson(Map<String, dynamic> json) =>
      _$UserModelFromJson(json);

  Map<String, dynamic> toJson() => _$UserModelToJson(this);

  factory UserModel.fromEntity(UserEntity entity) =>
      UserModelEntityExtension.fromEntity(entity);
}

---

3. Run generator

dart run build_runner build --delete-conflicting-outputs

---

Field Renaming

JSON name

@AutoField(name: 'created_at')
final DateTime createdAt;

Entity name

@AutoField(entityName: 'displayName')
final String display;

---

Custom Converters

@AutoField(
  name: 'created_at',
  toEntity: 'DateTime.parse(value)',
  fromEntity: 'value.toIso8601String()',
)
final String createdAt;

Nullable

@AutoField(
  toEntity: 'value == null ? null : DateTime.parse(value)',
  fromEntity: 'value?.toIso8601String()',
)
final String? createdAt;

---

Ignoring Fields

@AutoField(ignore: true)
final String tempOnly;

---

Automatic Type Support

Type	JSON	Entity
String	✅	✅
int	✅	✅
bool	✅	✅
double	✅	✅
DateTime	✅	✅
DateTime?	✅	✅
List	✅	✅
List	✅	✅
Nested AutoEntity	✅	✅
List	✅	✅

---

License

MIT