Angular Architecture: Monorepos and Micro Frontends

@BASTAcon & @ManfredSteyer

@ManfredSteyer Typical Module Structure Page ▪ 3 AppModule … …
… SharedModule Root Module Feature Modules Shared Modules SharedModule

@ManfredSteyer Contents • Monorepos • Strategic Design and DDD •
Nx & Incremental Compilation • Microfrontends

@ManfredSteyer Manfred Steyer

@ManfredSteyer Monorepos

@ManfredSteyer Monorepo Structure

@ManfredSteyer Advantages Everyone uses the latest versions No version conflicts
No burden with distributing libs

@ManfredSteyer Two Flavors • Like Workspaces/Solutions in different IDEs Project
Monorepo • E. g. used at Google or Facebook Company-wide Monorepo

@ManfredSteyer Moving back and forth Npm Registry

@ManfredSteyer Tooling & Generator https://nrwl.io/nx

@ManfredSteyer Visualize Module Structure

@ManfredSteyer Further Selected Features of Nx • Restricting access b/w
apps and libs • Just recompile changed apps • Parallel compilation in the cloud • Integration of tooling: Cypress, Playwright, Storybook, …

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

@ManfredSteyer DEMO

@ManfredSteyer DDD in a nutshell

@ManfredSteyer Methodology for bridging the gap b/w requirements and architecture/
design

@ManfredSteyer

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

@ManfredSteyer

@ManfredSteyer Example Flight System

@ManfredSteyer Booking Check-in Boarding Luggage Example Sub-Domains

@ManfredSteyer Finding Sub-Domains Book Flight Check-in Passenger Check-in Luggage Board
Plane Pickup Luggage Passenger Travel Agency Check-in Agent Boarding Agent

@ManfredSteyer Booking Boarding Bounded Context Ubiquitous Language Flight Price Seats
Passenger Tickets Flight Ticket

@ManfredSteyer Booking Luggage Boarding Check-in Context Map

@ManfredSteyer Booking Boarding 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 DEMO

@ManfredSteyer

@ManfredSteyer Finegrained Libraries • Units for dep graph • Unit
of recompilation* • Unit of retesting • Access restrictions • Information Hiding • Easy: Just ng g lib …

@ManfredSteyer Restricting Access on a folder basis Rainer Hahnekamp, AngularArchitects
@softarc/eslint-plugin-sheriff

@ManfredSteyer Micro Frontends? Short outlook

@ManfredSteyer Booking App Check-in App Boarding App Luggage App Microfrontends

@ManfredSteyer Shopping Card App Payment App Recommender App Shipping App
Microfrontends

@ManfredSteyer

@ManfredSteyer Booking Boarding Shared Feature Feature Feature Feature Feature …
… … … … … … … … @ManfredSteyer Flight App Deployment Monolith

… … … … … … … … Booking App Boarding App Microfrontends

… … … … … … … … Booking App Boarding App Option 1: One App per Domain Monorepo

… … … … … … … … Booking App Boarding App Option 2: One Monorepo per Domain Publish shared libs seperately via npm Repository n Repository 2 Repository 1

@ManfredSteyer Benefits Autonomous Teams Separate Development Separate Deployment Own architecture
decisions Own technology descisions

@ManfredSteyer Integration via Hyperlinks

@ManfredSteyer UI Composition w/ Hyperlinks µApp SPA µApp SPA µApp
SPA

@ManfredSteyer

@ManfredSteyer ✓ Simple  Loosing State  Load a new
Application

@ManfredSteyer

@ManfredSteyer Web Components for Shared Widgets?

@ManfredSteyer Integration via Shell

@ManfredSteyer µService Providing a (SPA based) Shell µApp µApp µApp
Shell

@ManfredSteyer

@ManfredSteyer Idea const Component = import('other-app/xyz') Does not work with
webpack/ Angular CLI Even lazy parts must be known at compile time!

@ManfredSteyer Webpack 5 Module Federation Shell (Host) Microfrontend (Remote) //
Maps Urls in // webpack config remotes: { mfe1: "http://..." } // Expose files in // webpack config exposes: { Cmp: './my.cmp.ts' } import('mfe1/Cmp')

@ManfredSteyer Dynamic Module Federation Shell (Host) Microfrontend (Remote) remotes: {
} exposes: { Cmp: './my.cmp.ts' } loadRemoteModule({ type: 'module', remoteEntry: 'http://…', exposedModule: './Cmp' })

@ManfredSteyer How to Get the Microfrontend's URL? Shell (Host) Microfrontend
(Remote) RemoteEntrypoint.js <script src="…"></script>

@ManfredSteyer How to Share Libs? Shell (Host) Microfrontend (Remote) shared:
[ "@angular/core", "…" ] shared: [ "@angular/core", "…" ]

@ManfredSteyer

@ManfredSteyer Default Behavior Selecting the highest compatible version ^10.0 ^10.1

@ManfredSteyer Default Behavior Conflict: No highest compatible version ^11.0 ^10.1

@ManfredSteyer Configuring Singletons shared: { "my-lib": { singleton: true }
} 11.0 10.1

@ManfredSteyer Configuring Singletons shared: { "my-lib": { singleton: true, strictVersion:
true // Error instead of warning! } } 11.0 10.1

@ManfredSteyer Relaxing Version Requirements shared: { "my-lib": { requiredVersion: ">=1.0.1
<11.1.1" } }

@ManfredSteyer

@ManfredSteyer ?

@ManfredSteyer Custom Builder

@ManfredSteyer

@ManfredSteyer 1) ng add @angular-architects/module-federation 2) Adjust generated configuration 3)
ng serve

@ManfredSteyer 1) npm i @angular-architects/module-federation -D 2) ng g @angular-architects/module-federation:init
3) Adjust generated configuration 4) ng serve

@ManfredSteyer

@ManfredSteyer Wrap them into Web Components Angular App (MFE) React
App (MFE)

@ManfredSteyer

@ManfredSteyer await import('other-app/web-cmp');

@ManfredSteyer await import('other-app/web-cmp'); const rootElm = document.createElement('web-cmp') document.body.appendChild(rootElm);

@ManfredSteyer await import('other-app/web-cmp'); const rootElm = document.createElement('web-cmp') document.body.appendChild(rootElm); WrapperComponent

@ManfredSteyer

@ManfredSteyer https://red-ocean-0fe4c4610.azurestaticapps.net

@ManfredSteyer Free eBook (5th Edition) ANGULARarchitects.io/book Module Federation & Nx

@ManfredSteyer Choosing a Solution

@ManfredSteyer Some General Advice Shared state, navigation b/w apps Hyperlinks
Legacy Apps or *very very* strong isolation? iframes Separate Deployment/ mix Technologies? Load Bundles on Demand Monolith little much yes no yes no Module Federation

@ManfredSteyer d Slides & Examples Remote Company Workshops and Consulting
http://angulararchitects.io

Angular Architecture: Monorepos and Micro Frontends

Angular Architecture: Monorepos and Micro Frontends

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