import { Injectable } from '@angular/core'; import { ComponentStore } from '@ngrx/component-store'; import { map } from 'rxjs'; export interface Currency { name: string; code: string; symbol: string; } export const currency: Currency[] = [ { name: 'Euro', code: 'EUR', symbol: '€' }, { name: 'Dollar US', code: 'USD', symbol: 'US$' }, { name: 'Dollar Autralien', code: 'AUD', symbol: 'AU$' }, { name: 'Livre Sterling', code: 'GBP', symbol: '£' }, { name: 'Dollar Canadien', code: 'CAD', symbol: 'CAD' }, ]; @Injectable() export class CurrencyService extends ComponentStore<{ code: string }> { readonly code$ = this.select((state) => state.code); readonly symbol$ = this.code$.pipe( map((code) => currency.find((c) => c.code === code)?.symbol ?? code), ); constructor() { super({ code: 'EUR' }); } }