Performance Tuning with Angular

Slides from my talk at Angular Berlin, Oct 2018

1. Through the Sound Barrier High-Performance Applications with Angular Manfred Steyer SOFTWAREarchitekt.at
2. About me… • Manfred Steyer • SOFTWAREarchitekt.at • Trainer & Consultant • Focus: Angular • Google Developer Expert (GDE) Page ▪ 2 Manfred Steyer
3. Turbo Button
4. Quick Wins Bundling Minification enableProdMode()
5. Contents • Lazy Loading and Preloading • Performance for Data Binding with OnPush • AOT and Tree Shaking • Caching with Service Worker • Server Side Rendering
6. Lazy Loading
7. Module Struktur Page ▪ 8 AppModule … … … SharedModule Root Module Feature Modules Shared Module
8. Lazy Loading Page ▪ 9 AppModule … … … SharedModule Root Module Feature Modules Shared Module
9. Root Module with Lazy Loading Page ▪ 10 const APP_ROUTE_CONFIG: Routes = [ { path: 'home', component: HomeComponent }, { path: 'flights', loadChildren: './[…]flight-booking.module#FlightBookingModule' } ];
10. Routes for Feature Modules Page ▪ 11 const FLIGHT_ROUTES = [ { path: '', component: FlightBookingComponent, […] }, […] }
11. Lazy Loading • Lazy Loading means: Loading it later • Better startup performance • Delay during execution for loading on demand
12. Preloading
13. Idea • Module that might be needed later are loaded after the application started • When module is needed it is available immediately Page ▪ 14
14. Activate Preloading Page ▪ 15 const AppRoutesModule = RouterModule.forRoot( ROUTE_CONFIG, { preloadingStrategy: PreloadAllModules });
15. Performance- Tuning with OnPush
16. DEMO
17. OnPush flights flight flight {{ flight.id }} {{ flight.id }} FlightSearch Card Card Angular just checks when “notified”
18. Activate OnPush @Component({ […] changeDetection: ChangeDetectionStrategy.OnPush }) export class FlightCard { […] @Input() flight; }
19. "Notify" about change? • Change bound data (@Input) • Angular compares just the object reference! • Raise Event within the component • Notify a bound observable • Trigger it manually
20. Change Inputs flights flight flight {{ flight.id }} {{ flight.id }} FlightSearch Card Card flightold === flightnew
21. Observables and OnPush <flight-card [item]="flights$ | async" […]> </flight-card>
22. DEMO
23. Not „all or nothing“ • You can use OnPush just for selected components • Using it compleatly: Redux • @ngrx/store
24. Ahead of Time (AOT) Compilation
25. Angular Compiler HTML Template JavaScript Template Compiler
26. Approaches • JIT: Just in Time, at runtime • AOT: Ahead of Time, during build
27. Advantages of AOT • Better Startup-Performance • Smaller Bundles: You don't need to include the compiler! • Tools can easier analyse the code • Remove not needed parts of frameworks • Tree Shaking
28. Angular CLI • ng build --prod • @ngtools/webpack with AotPlugin • Can be used without CLI too
29. DEMO
30. Tree Shaking
31. Challenges • Most tree shaking tools are conservative • They just remove code when they are 100% sure • Very often, they aren't sure :-) • Solution: Angular Build Optimizer • Rewrites compiled code • Currently: Experimental
33. Caching with Service Worker
34. What are Service Workers? • Background Tasks • Web App installs them • Are activated and deactivated on demand
35. Service Worker und Caching/ Offline • Intercept requests • Decide how to respond (Cache, Network) • Same Origin Policy • Caching Patterns • Cache only • Network only • Try cache first, then network • Try network first, then cache • etc.
37. Service Worker with Workbox (sw.js) importScripts('./assets/workbox-sw.js'); const workboxSW = new WorkboxSW();
38. Service Worker with Workbox (sw.js) importScripts('./assets/workbox-sw.js'); const workboxSW = new WorkboxSW(); const networkFirst = workboxSW.strategies.networkFirst(); const cacheFirst = workboxSW.strategies.cacheFirst();
39. Service Worker with Workbox (sw.js) importScripts('./assets/workbox-sw.js'); const workboxSW = new WorkboxSW(); const networkFirst = workboxSW.strategies.networkFirst(); const cacheFirst = workboxSW.strategies.cacheFirst(); workboxSW.router.registerRoute( new RegExp('^http:\/\/www.angular.at\/api\/'), networkFirst); workboxSW.router.registerRoute(/./, cacheFirst);
40. DEMO
41. Server Side Rendering
42. Why Server Side Rendering? Prerender 1st Page Start up performance Consumer
43. renderModuleFactory […] renderModuleFactory(moduleFactory, { document: indexFileContentsAsString, url: options.req.url }) .then(string => { […] }); […] Available since Angular 4.0
44. DEMO
45. Challenges Other conditions Separate Services for Server and Client-Seite Renderer abstracts DOM 3rd parts libs Angular 5: Server Side DOM Simulation (partly)
46. More about this • https://medium.com/@ManfredSteyer/angular-performance-tuning- article-series-6e3c33707b25
47. Conclusion Quick Wins Lazy Loading and Preloading AOT and Tree Shaking Caching w/ Service Worker OnPush w/ Immutables and Observables Consumer- Apps: Server Side Rendering
48. Contact [mail] manfred.steyer@SOFTWAREarchitekt.at [blog] SOFTWAREarchitekt.at [twitter] ManfredSteyer