feat(challenge16): di

apps/di/src/app/currency.service.ts

@@ -0,0 +1,29 @@
+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' });
+  }
+}