vnum 1.0.2

A library that enables value based enum behaviour using classes in flutter.

Vnum

A library that enables value based enum behaviour using classes in flutter

Usage:

@VnumDefinition
class CarType extends Vnum<String> {
  /// Cases
  static final CarType sedan = CarType.define("sedan-value");
  static final CarType suv = CarType.define("suv-value");
  static final CarType truck = CarType.define("truck-value");
  static final CarType none = CarType.define("unknown");

  /// Constructors
  CarType.define(String fromValue) : super.define(fromValue);
  factory CarType(String value) => Vnum.fromValue(value,CarType);
}

var car = CarType.sedan;
var carValue = car.value;
var carFromValue = CarType('suv-value');
var nonExisting = CarType('rocket') /// returns null

Comparison:

var sedan = CarType.sedan;
var truck = CarType.truck
print(sedan == truck);

Installation:

Add following reflectable, build_runner dependencies:

dependencies:
  flutter:
    sdk: flutter
  reflectable: ^2.0.10+1

dev_dependencies:
  flutter_test:
    sdk: flutter
  build_runner: ^1.0.0

Add following lines to your main.dart add the following imports:

import 'main.reflectable.dart';
import 'package:reflectable/reflectable.dart';

void main() {
  initializeReflectable();
}

In your Vnum files:

import 'package:Vnum/Vnum.dart';

Definition:

Define your enum with value of T type with following steps:

• Define your class which extends Vnum<T>

• Add @VnumDefinition attribute to your class

• Add public constructors

• Define your cases as static final with the same type of your Vnum

@VnumDefinition
class MyEnum extends Vnum<T> {
/// Case Definition
static final MyEnum case1 = MyEnum.define(value1);
static final MyEnum case2 = MyEnum.define(value2);

/// Used for defining cases
  MyEnum.define(String fromValue) : super.define(fromValue);

/// Used for loading enum using value
  factory MyEnum(String value) => Vnum.fromValue(value,MyEnum);
}

Generate codes:

Vnum is based on Dart Reflection and requires generating codes:

Use the following command in your terminal to generate reflection codes for your project

packages pub run build_runner build --delete-conflicting-outputs

Reflectable documentation: https://github.com/dart-lang/reflectable

For implementation:

• Json Serialization