Improving Start-up Performance with Lazy Loading in Angular

Talk from ng-conf 2017, April 2017 in Salt Lake City

Transcript

1. Improving Start-up Performance with Lazy Loading in Angular Manfred Steyer SOFTWAREarchitekt.at ManfredSteyer
2. About me … • Manfred Steyer • SOFTWAREarchitekt.at • Trainer & Consultant • Focus: Angular • Google Developer Expert (GDE) Page ▪ 2 Manfred Steyer
3. Contents • Lazy Loading and Preloading • Shared Modules and Lazy Loading Page ▪ 3
4. Lazy Loading Page ▪ 4
5. Module Structure Page ▪ 5 AppModule FeatureModule1 FeatureModule2 … SharedModule SharedModule SharedModule
6. Module Structure Page ▪ 6 AppModule FeatureModule1 FeatureModule2 … SharedModule SharedModule SharedModule
7. Root Module with Lazy Loading Page ▪ 7 const APP_ROUTE_CONFIG: Routes = [ { path: 'home', component: HomeComponent }, { path: 'flights', loadChildren: './[…]booking.module#BookingModule' } ];
8. Routes for Feature Module Page ▪ 8 const FLIGHT_ROUTES = [ { path: '', component: FlightBookingComponent, […] }, […] }
9. Build Configuration • Angular CLI: Done! • ngtools/webpack • Webpack • ngtools/webpack • Big thanks to the CLI-Team • Or: angular-router-loader • Big thanks to Brandon Roberts Page ▪ 9
10. Two Sides of a Coin
11. Lazy Loading • Lazy Loading means: Loading it later • Better startup performance • Delay during execution for loading on demand
12. Preloading Page ▪ 12
13. Idea • Modules that might be needed later are loaded after (!) the start of the application • When the module is actually needed, it is available immediately Page ▪ 13
14. Activating Preloading Page ▪ 14 const AppRoutesModule = RouterModule.forRoot( ROUTE_CONFIG, { preloadingStrategy: PreloadAllModules });
15. DEMO Page ▪ 15
16. Lazy Loading and Shared Modules Page ▪ 16
17. Lazy Loading and Shared Modules Page ▪ 18 AppModule FlightModule SharedModule includes includes (lazy) includes AuthService
18. Lazy Loading and Shared Modules Page ▪ 19 AppModule FlightModule SharedModule includes includes (lazy) includes AuthService AuthService
19. Lazy Loading and Shared Modules Page ▪ 20 AppModule FlightModule SharedModule includes includes (lazy) includes AuthService AuthService
20. Solution Page ▪ 21 AppModule FlightModule SharedModule includes (lazy) CoreModule includes includes Only import CoreModule into AppModule! Global Providers like AuthService
21. Huge CoreModule? Page ▪ 22 AppModule FlightModule SharedModule includes (lazy) CoreModule includes includes
22. Solution (for Libraries) Page ▪ 23 AppModule FlightModule AuthModule includes (lazy) CoreModule includes
23. Solution (for Libraries) Page ▪ 24 AppModule FlightModule AuthModule includes (lazy) includes (with Services) CoreModule includes includes (without Services)
24. Auth Module Page ▪ 25 @NgModule({ […], providers: [] }) export class AuthModule { }
25. Auth Module Page ▪ 26 @NgModule({ […], providers: [] }) export class AuthModule { static forRoot(): ModuleWithProviders { return { ngModule: AuthModule, providers: [AuthService, […]] } } }
26. Importing into AppModule @NgModule({ imports: [ AuthModule.forRoot() [...] ], declarations: [ ... ], bootstrap: [ ... ] }) export class AppModule { }
27. Importing into other Modules @NgModule({ imports: [ AuthModule [...] ], declarations: [ ... ], bootstrap: [ ... ] }) export class OtherModule { }
28. DEMO Page ▪ 29
29. Summary Page ▪ 30 Lazy Loading: Startup Performance CLI/ webpack splits chunks Preloading Strategy Use Core Module for global Services Shared Modules w/ and w/o Providers
30. Contact [mail] ms@SOFTWAREarchitekt.at [blog] SOFTWAREarchitekt.at [twitter] ManfredSteyer