Nest-kr/ddd

This library is for DDD

Installation

$ npm install --save @nest-kr/ddd

How to use

Import DDDModule

This will automatically register DomainEventHandlers to a DomainEventDispatcher.

import {DDDModule} from '@nest-kr/ddd';

@Module({
    imports: [DDDModule],
    providers: [UserDomainEventService],
})
export class AppModule {}

ValueObject

import {ValueObject} from '@nest-kr/ddd';

class Address extends ValueObject<Address>{

}

Identity

import {Identity} from '@nest-kr/ddd';

class Identity extends Identity<UserId>{

}

Entity

import {Entity} from '@nest-kr/ddd';

class User extends Entity<User, UserId>{

}

AggregateRoot

import {AggregateRoot} from '@nest-kr/ddd';

class Order extends AggregateRoot<Order, OrderId>{

}

Domain Event

import {DomainEvent} from '@nest-kr/ddd';

class UserCreated extends DomainEvent{

}

Domain Event Handler

import { Injectable } from '@nestjs/common';
import { DomainEventHandler } from '@nest-kr/ddd';

import { UserCreated } from '../../domain/events/UserCreated';

@Injectable()
export class UserDomainEventService {
    @DomainEventHandler(UserCreated)
    public handleUserCreated(userCreated: UserCreated): void {

    }
}

Domain Event Dispatcher

import { Repository, DomainEventDispatcher } from '@nest-kr/ddd';
import { Injectable } from '@nestjs/common';
...

@Injectable()
export class UserRepository extends Repository<User, UserId> {
    constructor(
        private readonly mapper: UserMapper,
        private readonly domainEventDispatcher: DomainEventDispatcher,
    ) {
        super();
    }


    async save(user: User): Promise<void> {
        const entity = this.mapper.toEntity(user);
        await this.ormRepository().save(entity);

        // Get domain events from aggregate root and dispatch all
        const events = user.getDomainEvents();
        this.domainEventDispatcher.dispatch(events);
    }

    ...

}