Addapptables microservices is a library for nodejs oriented to microservices with pattern design CQRS

Addapptables microservices with cqrs

- Addapptables microservices is a library for nodejs oriented to microservices,
this library is made to work with nestjs

- Example code

Getting Started

To get started, let's install the package through npm:

``
npm i @addapptables/microservice
`

If you use rabbitmq install
`
npm i amqplib
`

How to use

- Available adapters:
- KafkaBusAdapter
- LocalBusAdapter (rx)
- MqttBusAdapter
- NatsBusAdapter
- RabbitMQBusAdapter
- RedisBusAdapter

- Example with rabbitmq
`typescript
import { MicroserviceModule, ManagerAdapterBus, RabbitMQBusAdapter } from '@addapptables/microservice';
@Module({
imports: [
MicroserviceModule.withConfig({
adapter: ManagerAdapterBus.getInstance(RabbitMQBusAdapter)
.withConfig({
exchange: 'search-service',
host: process.env.BUS_URL
})
.build(),
logger: {
debug: false
}
})
],
controllers: [
...
],
providers: [
...
],
})
export class AppModule {}
`

- Create commands

`typescript
import { Command } from '@addapptables/microservice';

export class ClassCommandModel implements ICommandDto {
id: string;
}

export class CreateUserCommand extends Command {
public readonly action = 'action';
public readonly context = 'context';

constructor(public readonly data: ClassCommandModel) { super(data); }
}
`

- Create command handlers
`typescript
import { ICommandHandler, CommandHandler, ICommand } from '@addapptables/cqrs';

@CommandHandler(CreateUserCommand)
export class CommandHandler implements ICommandHandler {

handle(event: ClassCommandModel): any {
console.log(event);
// call your domain service
}

}

// ChildModule
@Module({
imports: [
...
],
controllers: [
...
],
providers: [
CommandHandler // very important
],
})
export class ChildModule {}
`

- Create query

`typescript
export class ClassQueryModel implements IQueryDto {
id: string;
}

export class CreateUserQuery extends Query {
public readonly action = 'action';
public readonly context = 'context';

constructor(public readonly data: ClassQueryModel) { super(data); }
}
`

- Create query handlers
`typescript
@QueryHandler(ClassQueryModel)
export class FindOneUserHandler implements IQueryHandler {

constructor(private readonly userService: UserDomainService) { }

handle(event: ClassQueryModel): any {
return this.userService.findOneByQuery(event.data);
}

}

// ChildModule
@Module({
imports: [
...
],
controllers: [
...
],
providers: [
FindOneUserHandler // very important
],
})
export class ChildModule {}
`

- Create events

`typescript

export class ClassEventModel implements IEventDto {
id: string;
}

export class UserCreatedEvent extends Command {
public readonly action = 'action';
public readonly context = 'context';

constructor(public readonly data: ClassEventModel) { super(data); }
}
`

`typescript
@EventHandler(UserCreatedEvent)
export class ActionHandler implements IEventHandler {

handle(event: UserCreatedEvent): any {
console.log(event);
// call your domain service
}

}

// ChildModule
@Module({
imports: [
...
],
controllers: [
...
],
providers: [
ActionHandler // very important
],
})
export class ChildModule {}
``