NgRx v8を使ってみよう Angularもくもく会 in Fukuoka #9

Noriyuki Shinpuku ng-fukuoka organizer VEGA corporation Co., Ltd. @puku0x

Angular

Full-fledged & opinionated Angular Protractor Forms PWA Augury Language Services Router Elements CDK Universal Karma Labs Compiler i18n Http Material Animations CLI

State management?

RxJS

Basic state management ● BehaviorSubject ● ReplaySubject ○ No initial value ○ No current value getter

BehaviorSubject import { Injectable } from '@angular/core'; import { BehaviorSubject } from 'rxjs'; @Injectable({ providedIn: 'root' }) export class CouterService { private counter = new BehaviorSubject(0); // Initial value = 0 get counter$() { return this.counter.asObservable(); } increment() { const value = this.counter.getValue(); this.counter.next(value + 1); } }

ReplaySubject import { Injectable } from '@angular/core'; import { BehaviorSubject } from 'rxjs'; @Injectable({ providedIn: 'root' }) export class CouterService { private counter = new ReplaySubject(1); // Buffer size = 1 get counter$() { return this.counter.asObservable(); } setCounter(value: number) { this.counter.next(value); } }

Complex state management?

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NgRx ● RxJS powered Redux for Angular ● Type-safe and performant ● Community driven

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Does it have many boilerplates?

NgRx v8 has less boilerplates!

https://blog.angularindepth.com/ngrx-action-creators-redesigned-d396960e46da

Action creator factory import { createAction, props } from '@ngrx/store'; export const increment = createAction( '[Counter] Increment' ); export const setValue = createAction( '[Counter] Set value, props<{ value: number }>() );

Reducer creator factory import { createReducer, on } from '@ngrx/store'; import { increment, setValue } from './counter.actions'; export const initialState = 0; const counterReducer = createReducer(initialState, on(increment, state => state + 1), // No more switch-case! on(setValue, (state, { value }) => value) );

Effect creator factory import { Actions, ofType, createEffect } from '@ngrx/effects'; import { tap } from 'rxjs/operators'; import { setValue } from '../actions'; @Injectable() export class CounterEffects { constructor(private actions$: Actionn) {} setValue$ = createEffect(() => // No more @Effect decorator! this.actions$.pipe( ofType(setValue), tap(({ value }) => console.log(`${value}`)) ), { dispatch: false } );

Creator factories make NgRx simple!

Recap ● NgRx provides Redux for Angular ● Less boilerplate with creator factories ● Try it now! https://ngrx.io/ https://stackblitz.com/edit/ngrx-todo-v8

Thank you! @puku0x Noriyuki Shinpuku