Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
#2 NestJS Paris meetup - NestJS & Event Store
Search
Sylvain PONTOREAU
September 10, 2019
Programming
0
650
#2 NestJS Paris meetup - NestJS & Event Store
NestJS & Event Store (CQRS & Event Sourcing)
Presenation made during NestJS Paris meetup.
Sylvain PONTOREAU
September 10, 2019
Tweet
Share
More Decks by Sylvain PONTOREAU
See All by Sylvain PONTOREAU
aMS Lausanne - Préparez-vous à une virée intersidérale avec Azure Cosmos DB 🧑🚀
spontoreau
0
10
TypeScript - 45 minutes pour s’y mettre !
spontoreau
0
110
Event Sourcing avec Azure, quelle base de données choisir
spontoreau
0
26
Decorators in TypeScript 5.0, everything you need to know!
spontoreau
0
390
Leverage your CI/CD at the next level with Github actions
spontoreau
0
9
Commit comme un(e) "Hipster" avec Gitmoji !
spontoreau
0
99
Bird of a Feather - TypeScript (Devoxx 2022)
spontoreau
0
17
GitHub - Du besoin jusqu'à la production avec Github et Azure
spontoreau
0
16
Behavior Driven Development
spontoreau
1
200
Other Decks in Programming
See All in Programming
なぜ宣言的 UI は壊れにくいのか / Why declarative UI is less fragile
uenitty
29
13k
Harnessing Large Language Models for Training-free Video Anomaly Detection
tereka114
1
1.3k
How to use Macrobenchmark
veronikapj
0
160
I/O Extended Android in Korea 2024 ~ Whats new in Android development tools
pluu
0
250
Activities at Cairo Library
cairolibrary720
0
1.2k
さきがけから振り返るアーキテクチャ刷新 / Reflecting on the Architectural Renewal from the Vanguard
nrslib
2
780
Async Await: Mastering Python's Time-Bending Tricks - EuroPython2024
yanbo
1
290
【Go言語】golangci-lintの使い方
tomo1227
0
280
AWS初心者ってどうやってAWSを学ぶ?〜アプリエンジニアがやってよかったアーキテクチャ学習方法〜
yamanashi_ren01
0
190
CSC307 Lecture 12
javiergs
PRO
0
220
CSC307 Lecture 13
javiergs
PRO
0
150
初心者がおさえておきたいAWS CDKのベストプラクティス 2024
konokenj
15
7.3k
Featured
See All Featured
What the flash - Photography Introduction
edds
65
11k
[RailsConf 2023] Rails as a piece of cake
palkan
35
4.4k
Stop Working from a Prison Cell
hatefulcrawdad
266
20k
Web Components: a chance to create the future
zenorocha
307
41k
Faster Mobile Websites
deanohume
303
30k
Statistics for Hackers
jakevdp
792
220k
Into the Great Unknown - MozCon
thekraken
20
1.3k
Designing Dashboards & Data Visualisations in Web Apps
destraynor
226
52k
Six Lessons from altMBA
skipperchong
24
3.2k
Responsive Adventures: Dirty Tricks From The Dark Corners of Front-End
smashingmag
248
20k
Embracing the Ebb and Flow
colly
81
4.3k
Designing with Data
zakiwarfel
96
5k
Transcript
September 10, 2019 | NestJS Paris | Sylvain Pontoreau NestJS
& Event Store
Formerly Microsoft In ❤ with Co-organizer Who I am? @spontoreau
Paris TypeScript @ParisTypeScript www.typescript.paris
Domain Driven Design • DDD is not a Framework nor
a Methodology… • … it's an approach to dealing with complexity • DDD focusing: • The domain representation • The domain logic • Technical aspects are secondary • Just a part that enforcing the domain
Opposite of Data Driven Development Data Driven Development Domain Driven
Design != Data structure Entity Relationship CRUD Behavior Bounded Context Event
Query Just a read operation Command Data validation Business logic
Persistence CQRS
CQRS GetBookById Query CreateBook Command GetAllBook Query DeleteBook Command …
… Dispatcher Read DB Dispatcher QueryHandler CommandHandler Write DB Validation Plugin Monitoring Plugin Telemetry Plugin … Eventual consistency
https://martinfowler.com/eaaDev/EventSourcing.html Event Sourcing
Event Sourcing & CQRS
CQRS & Event Sourcing GetBookById Query CreateBook Command GetAllBook Query
DeleteBook Command … … Dispatcher Read DB Dispatcher QueryHandler CommandHandler Event Store Projection Projection AggregateRoot State Events
Our focus in this talk GetBookById Query CreateBook Command GetAllBook
Query DeleteBook Command … … Dispatcher Read DB Dispatcher QueryHandler CommandHandler Event Store Projection Projection AggregateRoot State Events
NestJS, Commands, Aggregates & Events Command Bus EventBus EventPublisher Repository
CommandHandler Controller/Service Aggregate Execute Comand Execute Handler Get Aggregate Merge Aggregate Apply events Execute behaviors IEventPublisher Publish events DefaultPubSub Default implementation EventHandler EventStore Publisher
Custom EventPublisher & MessageSource import { IEvent } from './event.interface';
export interface IEventPublisher { publish<T extends IEvent>(event: T); } import { Subject } from 'rxjs'; import { IEvent } from './event.interface'; export interface IMessageSource { bridgeEventsTo< T extends Ievent >(subject: Subject<T>); } • IEventPublisher • MessageSource export class UserModule implements OnModuleInit { constructor( private readonly eventBus: EventBus, private readonly eventStorePublisher: EventStorePublisher ) {} onModuleInit() { this.eventBus.publisher = this.eventStorePublisher; } } • Module
Which database for storing events? Choose what you want! Please
try me!!!
Event Store, the stream database https://eventstore.org
Demo
Resources • CQRS & Event Sourcing • CQRS pattern: https://docs.microsoft.com/en-US/azure/architecture/patterns/cqrs
• Event Sourcing pattern: https://docs.microsoft.com/en-us/azure/architecture/patterns/event-sourcing • Tackle business complexity in a Microservice with DDD and CQRS: https://docs.microsoft.com/en- us/dotnet/standard/microservices-architecture/microservice-ddd-cqrs-patterns/ • NestJS CQRS module: https://docs.nestjs.com/recipes/cqrs • Event Store website: https://eventstore.org • Talk’s sample: https://github.com/spontoreau/nestjs-eventstore-demo • node-eventstore-client NPM package: https://github.com/nicdex/node-eventstore-client • gereventstore-pomise NPM package : https://github.com/RemoteMetering/geteventstore-promise • Jérôme Rouaix presentation on CQRS & ES: https://gitpitch.com/jrouaix/cqrs-es-presentation/master#/ • Arnaud Lemaire talk on CQRS, ES and DDD: https://www.youtube.com/watch?v=qBLtZN3p3FU • Greg Young, A decade of DDD, CQRS and ES: https://www.youtube.com/watch?v=LDW0QWie21s
Questions?
Thank you!