boilerplate_generators 2.0.4

Set of code generators for copyWith and copyWithNull methods with deepCopy support, Equatable props generation.

The Set of code generators reduce boilerplate code writing.

Installation

Add dependencies to your pubspec.yaml

dependencies:
  boilerplate_annotations:

dev_dependencies:
  boilerplate_generators:
  build_runner:

Generators

• CopyWith
• Props

CopyWith

The code generator for copyWith and copyWithNull methods generation supports deep copy and field ignoring.

Usage

• Annotate a class with the @copyWith annotation
• Add a part file - part 'your_file_name.g.dart'
• Run the build_runner.

Methods copyWith, and copyWithNull will be generated.

part 'address.g.dart';

@copyWith
class Address  {
    final String? street;
    final int? home;
    const Address({this.street, this.home});
}

If you want to disable the copyWithNull method generation, pass "copyWithNull = false" to the CopyWith annotation.

@CopyWith(copyWithNull: false)
class Address  {
  final String? street;
  final int? home;
  const Address({this.street, this.home});
}

copyWith and copyWithNull difference

The copyWith method rejects null.

@copyWith
class Payment {
  final int id;
  final String? description;
  const Payment({required this.id, this.description});
}

const payment = Payment(id: 4, description: 'test',);

print(payment.copyWith(description: null)); // Payment(id:4, description: test)

The copyWithNull method allows a copy with a null value.

@copyWith
class Payment {
  final int id;
  final String? description;
  const Payment({required this.id, this.description});
}

const payment = Payment(id: 4, description: 'test',);

print(payment.copyWithNull(description: null)); // Payment(id:4, description: null)

Deep copy

With deep copy support, you can call copyWith and copyWithNull methods of objects that a class contains and get a new instance of a class with an updated object. A class and objects that a class contains must be annotated with the @copyWith annotation.

@copyWith
class Payment {
final int id;
final String? description;
final Customer? customer;
const Payment({required this.id, this.customer, this.description});
}

@copyWith
class Customer {
final int id;
final String name;
final String surname;
final String? patronymic;
const Customer({
  required this.id,
  required this.name,
  required this.surname,
  this.patronymic,
});
}

const payment = Payment(
id: 4,
customer: Customer(
  id: 1,
  name: 'John',
  surname: 'Dou',
),
);

print(payment.copyWith.customer!(name: 'Bob')); // Payment(id: 4, customer: Customer(id: 1,name: 'Bob',surname: 'Dou'))

Ignore field

If you want a class field to be excluded from copyWith and copyWithNull methods generation, you need to annotate this field with the @copyWithExclude annotation. In this case, it will be impossible to change this field with these methods.

@copyWith
class Payment {
@copyWithExclude
final int id;
final String? description;
final Customer? customer;
const Payment({required this.id, this.customer, this.description});
}

Props

The code generator generates equatable props.

Usage

• Annotate a class with the @props annotation
• Add a part file - part 'your_file_name.g.dart'
• Override the props getter to return the _${your class name}Props(this);
• Run the build_runner.

Generated props will contain all final class fields.

part 'address.g.dart';

@props
class Address extends Equatable {
    final String? street;
    final int? home;
    const Address({this.street, this.home});
}
  @override
  List<Object?> get props => _$AddressProps(this);
}

Super class props

If your class extends from another class that uses Equatable, you need to add props from a superclass. You need to pass superclass props to the superProps parameter.

@props
class First extends Equatable {
  final String data;
  First(this.data);

  @override
  List<Object?> get props => _$FirstProps(this);
}

@props
class Second extends First {
  final String second;
  Second(this.second, String data) : super(data);

  @override
  List<Object?> get props => _$SecondProps(this, superProps: super.props);
}

Ignore field

If you want a class field to be excluded from props generation, you need to annotate this field with the @propsExclude annotation. In this case, props will not contain this field.

@props
class Address extends Equatable {
    @propsExclude
    final String? street;
    final int? home;
    const Address({this.street, this.home});
}
  @override
  List<Object?> get props => _$AddressProps(this);
}