Domain-Driven Design and Angular

@ManfredSteyer s ManfredSteyer

What do we need for a good architecture? Experience

@ManfredSteyer Sharing Experience for Architectures BEST PRACTICES PATTERNS METHODOLOGY

@ManfredSteyer Domain Driven Design

@ManfredSteyer How to create sustainable frontend architectures with ideas from
DDD? ?

@ManfredSteyer Contents 1) DDD in a Nutshell 2) Monorepos 3)
Monorepos & DDD 4) Automation

@ManfredSteyer About me… Manfred Steyer, ANGULARarchitects.io Angular Trainings and Consultancy
Frankfurt, Munich, Vienna, Remote In-House: everywhere https://ANGULARarchitects.at/workshops Google Developer Expert for Angular Trusted Collaborator in the Angular Team Manfred Steyer

@ManfredSteyer 1) DDD in a nutshell

@ManfredSteyer Domain Driven Design Strategic Design Tactical Design Decomposing a
System Design Patterns & Practices

@ManfredSteyer This is what Strategic DDD prevents

@ManfredSteyer Example e-Procurement System

@ManfredSteyer Catalog Approval Specification Ordering Example Sub-Domains

@ManfredSteyer Request Product Specify Order Approve Order Send Order Request
Budget Approve Budget Budget Hierarchy Manager Manager Employee IT-Expert Manager Buying Agent Product

@ManfredSteyer Catalog Approval Specification Ordering Context Map

@ManfredSteyer Approval Specification Context Map Catalog Catalog Shared Kernel

@ManfredSteyer Catalog Approval API

@ManfredSteyer Lots of additional approaches for cross-domain communication …

@ManfredSteyer 2) Monorepos

@ManfredSteyer Workspace

@ManfredSteyer Creating a Workspace npm install -g @angular/cli ng new
workspace cd workspace ng generate app my-app ng generate lib my-lib ng serve --project my-app ng build --project my-app

@ManfredSteyer Advantages No version conflicts No burden with distributing libs

@ManfredSteyer Moving back and forth Npm Registry

@ManfredSteyer https://nrwl.io/nx

@ManfredSteyer Visualize Module Structure

@ManfredSteyer Creating a Workspace npm install -g @angular/cli npm init
nx-workspace myworkspace cd workspace ng generate app my-app ng generate lib my-lib ng serve --project my-app ng build --project my-app

@ManfredSteyer 3) Nx Monorepos and Strategic Design

@ManfredSteyer Catalog Ordering Shared Feature Feature Feature Feature Feature UI
UI UI UI UI UI UI UI UI Domain Domain Domain Domain Domain Domain Util Util Util Util Util Util Enterprise Monorepo Patterns, Nrwl 2018: https://tinyurl.com/y2jjxld7 @ManfredSteyer Shared Kernel (if really needed) & other libs Smart Comp. Dumb Comp.

@ManfredSteyer Catalog Ordering Shared Feature API Feature Feature Feature Feature
UI UI UI UI UI UI UI UI UI Domain Domain Domain Domain Domain Domain Util Util Util Util Util Util @ManfredSteyer

@ManfredSteyer Application Domain Model Infrastructure Isolate your domain! Domain e.
g. data access Use case specific facades, state management Entities, biz logic

@ManfredSteyer Alternatives to layering • e. g. Hexagonal Architecture, Clean
Architecture • Anyway: We need to restrict access b/w libraries

@ManfredSteyer DEMO

@ManfredSteyer Finegrained Libraries • Unit of recompilation • Unit of
retesting • Access restrictions • Information Hiding

@ManfredSteyer Facades and State Management

@ManfredSteyer

@ManfredSteyer Product ProductGroup Order ValidateOrder ProductDataService OrderDataService BrowseProductsFacade Catalog Domain
Lib

@ManfredSteyer Facade (Application Service) @Injectable({ providedIn: 'root' }) export class
ProductFacade { […] }

ProductFacade { public products: Product[] = []; […] } State!

ProductFacade { public products: Product[] = []; constructor(private productService: ProductService) { } […] }

ProductFacade { public products: Product[] = []; constructor(private productService: ProductService) { } search(category: string): void { […] } }

ProductFacade { public products: Product[] = []; constructor(private productService: ProductService) { } search(category: string): void { […] } } SPA has to pull :-(

ProductFacade { public products: Observable<Product[]>; constructor(private productService: ProductService) { } search(category: string): void { […] } } Also key for messaging

@ManfredSteyer App Home Catalog Search RatingFacade ProductFacade SearchFacade Facades Have
State

@ManfredSteyer App Home Catalog Search RatingFacade ProductFacade SearchFacade Facades Have
State Store (z. B. Redux/ NGRX) Observable Action

@ManfredSteyer 4) Automation

@ManfredSteyer Nx Plugin

@ManfredSteyer DEMO

@ManfredSteyer Announcement Free eBook! https://leanpub.com/enterprise-angular

Summary • Slicing into sub-domains • Slicing into layers •
Finegrained libraries • Enforce restrictions • Automation with Nx Plugins

@ManfredSteyer

@ManfredSteyer Contact and Downloads [web] ANGULARarchitects.io [twitter] ManfredSteyer d Slides
& Examples Public: Frankfurt, Munich, Vienna In-House: everywhere http://softwarearchitekt.at/workshops

Domain-Driven Design and Angular

Domain-Driven Design and Angular

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