ZenGen #

This project provides a pub transformer to generate boilerplate code.

This library is inspired from the project Lombok in the Java world.

Warning #

Dart file modifications are not yet well integrated in the Dart editor.

If you run a web app use pub serve and launch dartium with localhost:8080 instead of Run in Dartium on your original file.

If you run a server app launch the built version of your dart file after a pub build instead of Run on your original file.

Features #

@ToString() #

Annotating a class with @ToString() will generate an implementation of String toString() built by default with its public getters.

For instance :

@ToString()
class A {
  final a;
  final int b;
  A(this.a, this.b);
}

will be transformed to :

@ToString()
class A {
  final a;
  final int b;
  A(this.a, this.b);
  @generated @override String toString() => "A(a=$a, b=$b)";
}

The code generated can be customized with the following optional parameters:

• callSuper: if set to true the result of toString will contains the result of super.toString().
• exclude: a list of getter names can be exclude with this argument.
• includePrivate: if set to true the generation will include private getters.

@EqualsAndHashCode() #

Annotating a class with @EqualsAndHashCode() will generate an implementation of bool operator ==(o) and int get hashCode built by default with its public getters.

For instance :

@EqualsAndHashCode()
class A {
  final a;
  final int b;
  A(this.a, this.b);
}

will be transformed to :

@EqualsAndHashCode()
class A {
  final a;
  final int b;
  A(this.a, this.b);
  @generated @override int get hashCode => hashObjects([a, b]);
  @generated @override bool operator ==(o) => identical(this, o) || o.runtimeType == runtimeType && o.a == a && o.b == b;
}

The code generated can be customize with the following optional parameters:

• callSuper: if set to true the generated code will use additionnally super.hashCode and super == o.
• exclude: a list of getter names can be exclude with this argument.
• includePrivate: if set to true the generation will include private getters.

@Delegate() #

Annotating a field/getter with @Delegate() will add to the enclosing class all the public methods available on the type of the field/getter.

For instance :

import 'package:zengen/zengen.dart';
abstract class A {
  m1();
}
class B {
  @Delegate() A _a;
}

will be transformed to :

import 'package:zengen/zengen.dart';
abstract class A {
  m1();
}
class B {
  @Delegate() A _a;
  @generated dynamic m1() => _a.m1();
}

The code generated can be customize with the following optional parameters:

• exclude: a list of members can be exclude with this argument.

@Lazy() #

Annotating a field with @Lazy() will make it lazy computed.

For instance :

import 'package:zengen/zengen.dart';
class A {
  @Lazy() var a = "String";
}

will be transformed to :

import 'package:zengen/zengen.dart';
class A {
  @generated dynamic get a => _lazyFields.putIfAbsent(#a, () => "String");
  @generated set a(dynamic v) => _lazyFields[#a] = v;
  @generated final _lazyFields = <Symbol, dynamic>{};
}

The lazy fields are stored into _lazyFields by field names. If the field is final no setter will be generated.

Usage #

To use this library in your code :

• add a dependency in your pubspec.yaml :

dependencies:
  zengen: any

• add the transformer in your pubspec.yaml :

transformers:
- zengen

• add import in your dart code :

import 'package:zengen/zengen.dart';

License #

Apache 2.0