feat(front-end): faster load

frontend/src/app/core/i18n/static-translate.loader.ts

@@ -1,22 +1,89 @@
-import { Injectable } from '@angular/core';
+import { isPlatformBrowser, isPlatformServer } from '@angular/common';
+import {
+  Injectable,
+  PLATFORM_ID,
+  TransferState,
+  inject,
+  makeStateKey,
+} from '@angular/core';
 import { TranslateLoader, TranslationObject } from '@ngx-translate/core';
-import { Observable, of } from 'rxjs';
-import de from '../../../assets/i18n/de.json';
-import en from '../../../assets/i18n/en.json';
-import fr from '../../../assets/i18n/fr.json';
-import it from '../../../assets/i18n/it.json';
+import { from, Observable } from 'rxjs';
 
-const TRANSLATIONS: Record<string, TranslationObject> = {
-  it: it as TranslationObject,
-  en: en as TranslationObject,
-  de: de as TranslationObject,
-  fr: fr as TranslationObject,
+type SupportedLang = 'it' | 'en' | 'de' | 'fr';
+
+const FALLBACK_LANG: SupportedLang = 'it';
+const translationCache = new Map<SupportedLang, Promise<TranslationObject>>();
+
+const translationLoaders: Record<SupportedLang, () => Promise<TranslationObject>> = {
+  it: () =>
+    import('../../../assets/i18n/it.json').then(
+      (module) => module.default as TranslationObject,
+    ),
+  en: () =>
+    import('../../../assets/i18n/en.json').then(
+      (module) => module.default as TranslationObject,
+    ),
+  de: () =>
+    import('../../../assets/i18n/de.json').then(
+      (module) => module.default as TranslationObject,
+    ),
+  fr: () =>
+    import('../../../assets/i18n/fr.json').then(
+      (module) => module.default as TranslationObject,
+    ),
 };
 
 @Injectable()
 export class StaticTranslateLoader implements TranslateLoader {
+  private readonly platformId = inject(PLATFORM_ID);
+  private readonly transferState = inject(TransferState);
+
   getTranslation(lang: string): Observable<TranslationObject> {
-    const normalized = String(lang || 'it').toLowerCase();
-    return of(TRANSLATIONS[normalized] ?? TRANSLATIONS['it']);
+    const normalized = this.normalizeLanguage(lang);
+    return from(this.loadTranslation(normalized));
+  }
+
+  private normalizeLanguage(lang: string): SupportedLang {
+    const normalized = String(lang || FALLBACK_LANG).toLowerCase();
+    return normalized in translationLoaders
+      ? (normalized as SupportedLang)
+      : FALLBACK_LANG;
+  }
+
+  private loadTranslation(lang: SupportedLang): Promise<TranslationObject> {
+    const transferStateKey =
+      makeStateKey<TranslationObject>(`i18n:${lang.toLowerCase()}`);
+    if (
+      isPlatformBrowser(this.platformId) &&
+      this.transferState.hasKey(transferStateKey)
+    ) {
+      const transferred = this.transferState.get(transferStateKey, {});
+      this.transferState.remove(transferStateKey);
+      return Promise.resolve(transferred);
+    }
+
+    const cached = translationCache.get(lang);
+    if (cached) {
+      return cached;
+    }
+
+    const pending = translationLoaders[lang]()
+      .then((translation) => {
+        if (
+          isPlatformServer(this.platformId) &&
+          !this.transferState.hasKey(transferStateKey)
+        ) {
+          this.transferState.set(transferStateKey, translation);
+        }
+        return translation;
+      })
+      .catch(() =>
+        lang === FALLBACK_LANG
+          ? Promise.resolve({})
+          : this.loadTranslation(FALLBACK_LANG),
+      );
+
+    translationCache.set(lang, pending);
+    return pending;
   }
 }

frontend/src/app/core/layout/navbar.component.ts

@@ -1,5 +1,12 @@
 import { CommonModule } from '@angular/common';
-import { Component, DestroyRef, computed, inject, signal } from '@angular/core';
+import {
+  afterNextRender,
+  Component,
+  DestroyRef,
+  computed,
+  inject,
+  signal,
+} from '@angular/core';
 import { takeUntilDestroyed } from '@angular/core/rxjs-interop';
 import {
   NavigationStart,
@@ -58,16 +65,9 @@ export class NavbarComponent {
   ];
 
   constructor(public langService: LanguageService) {
-    if (!this.shopService.cartLoaded()) {
-      this.shopService
-        .loadCart()
-        .pipe(takeUntilDestroyed(this.destroyRef))
-        .subscribe({
-          error: () => {
-            this.shopService.cart.set(null);
-          },
+    afterNextRender(() => {
+      this.scheduleCartWarmup();
     });
-    }
 
     this.router.events
       .pipe(takeUntilDestroyed(this.destroyRef))
@@ -96,6 +96,9 @@ export class NavbarComponent {
   toggleCart(): void {
     this.closeMenu();
     this.isCartOpen.update((open) => !open);
+    if (this.isCartOpen()) {
+      this.loadCartIfNeeded();
+    }
   }
 
   closeCart(): void {
@@ -192,5 +195,44 @@ export class NavbarComponent {
       .subscribe();
   }
 
+  private scheduleCartWarmup(): void {
+    if (typeof window === 'undefined') {
+      this.loadCartIfNeeded();
+      return;
+    }
+
+    const warmup = () => this.loadCartIfNeeded();
+    const idleCallback = (
+      window as Window & {
+        requestIdleCallback?: (
+          callback: IdleRequestCallback,
+          options?: IdleRequestOptions,
+        ) => number;
+      }
+    ).requestIdleCallback;
+
+    if (typeof idleCallback === 'function') {
+      idleCallback(() => warmup(), { timeout: 1500 });
+      return;
+    }
+
+    window.setTimeout(warmup, 300);
+  }
+
+  private loadCartIfNeeded(): void {
+    if (this.shopService.cartLoaded() || this.shopService.cartLoading()) {
+      return;
+    }
+
+    this.shopService
+      .loadCart()
+      .pipe(takeUntilDestroyed(this.destroyRef))
+      .subscribe({
+        error: () => {
+          this.shopService.cart.set(null);
+        },
+      });
+  }
+
   protected readonly routes = routes;
 }

frontend/src/app/features/shop/product-detail.component.ts

@@ -1,5 +1,6 @@
 import { CommonModule, isPlatformBrowser } from '@angular/common';
 import {
+  afterNextRender,
   Component,
   DestroyRef,
   Injector,
@@ -193,16 +194,9 @@ export class ProductDetailComponent {
   );
 
   constructor() {
-    if (!this.shopService.cartLoaded()) {
-      this.shopService
-        .loadCart()
-        .pipe(takeUntilDestroyed(this.destroyRef))
-        .subscribe({
-          error: () => {
-            this.shopService.cart.set(null);
-          },
+    afterNextRender(() => {
+      this.scheduleCartWarmup();
     });
-    }
 
     combineLatest([
       toObservable(this.productSlug, { injector: this.injector }),
@@ -282,6 +276,45 @@ export class ProductDetailComponent {
       );
   }
 
+  private scheduleCartWarmup(): void {
+    if (typeof window === 'undefined') {
+      this.loadCartIfNeeded();
+      return;
+    }
+
+    const warmup = () => this.loadCartIfNeeded();
+    const idleCallback = (
+      window as Window & {
+        requestIdleCallback?: (
+          callback: IdleRequestCallback,
+          options?: IdleRequestOptions,
+        ) => number;
+      }
+    ).requestIdleCallback;
+
+    if (typeof idleCallback === 'function') {
+      idleCallback(() => warmup(), { timeout: 1500 });
+      return;
+    }
+
+    window.setTimeout(warmup, 300);
+  }
+
+  private loadCartIfNeeded(): void {
+    if (this.shopService.cartLoaded() || this.shopService.cartLoading()) {
+      return;
+    }
+
+    this.shopService
+      .loadCart()
+      .pipe(takeUntilDestroyed(this.destroyRef))
+      .subscribe({
+        error: () => {
+          this.shopService.cart.set(null);
+        },
+      });
+  }
+
   selectImage(mediaAssetId: string): void {
     this.setSelectedImageAssetId(mediaAssetId);
   }

frontend/src/app/features/shop/shop-page.component.ts

@@ -1,5 +1,6 @@
 import { CommonModule } from '@angular/common';
 import {
+  afterNextRender,
   Component,
   DestroyRef,
   Injector,
@@ -89,16 +90,9 @@ export class ShopPageComponent {
   readonly cartHasItems = computed(() => this.cartItems().length > 0);
 
   constructor() {
-    if (!this.shopService.cartLoaded()) {
-      this.shopService
-        .loadCart()
-        .pipe(takeUntilDestroyed(this.destroyRef))
-        .subscribe({
-          error: () => {
-            this.shopService.cart.set(null);
-          },
+    afterNextRender(() => {
+      this.scheduleCartWarmup();
     });
-    }
 
     combineLatest([
       toObservable(this.categorySlug, { injector: this.injector }),
@@ -150,6 +144,45 @@ export class ShopPageComponent {
       });
   }
 
+  private scheduleCartWarmup(): void {
+    if (typeof window === 'undefined') {
+      this.loadCartIfNeeded();
+      return;
+    }
+
+    const warmup = () => this.loadCartIfNeeded();
+    const idleCallback = (
+      window as Window & {
+        requestIdleCallback?: (
+          callback: IdleRequestCallback,
+          options?: IdleRequestOptions,
+        ) => number;
+      }
+    ).requestIdleCallback;
+
+    if (typeof idleCallback === 'function') {
+      idleCallback(() => warmup(), { timeout: 1500 });
+      return;
+    }
+
+    window.setTimeout(warmup, 300);
+  }
+
+  private loadCartIfNeeded(): void {
+    if (this.shopService.cartLoaded() || this.shopService.cartLoading()) {
+      return;
+    }
+
+    this.shopService
+      .loadCart()
+      .pipe(takeUntilDestroyed(this.destroyRef))
+      .subscribe({
+        error: () => {
+          this.shopService.cart.set(null);
+        },
+      });
+  }
+
   productCartQuantity(productId: string): number {
     return this.shopService.quantityForProduct(productId);
   }

frontend/src/index.html

@@ -11,14 +11,32 @@
     <base href="/" />
     <meta name="viewport" content="width=device-width, initial-scale=1" />
     <link rel="icon" type="image/png" href="assets/images/Fav-icon.png" />
+    <link rel="preconnect" href="https://fonts.googleapis.com" />
+    <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin />
+    <link
+      href="https://fonts.googleapis.com/css2?family=IBM+Plex+Sans:wght@300;400;500;600&family=Space+Grotesk:wght@400;500;600;700&display=swap"
+      rel="stylesheet"
+      media="print"
+      onload="this.media='all'"
+    />
+    <noscript>
       <link
         href="https://fonts.googleapis.com/css2?family=IBM+Plex+Sans:wght@300;400;500;600&family=Space+Grotesk:wght@400;500;600;700&display=swap"
         rel="stylesheet"
       />
+    </noscript>
+    <link
+      href="https://fonts.googleapis.com/icon?family=Material+Icons"
+      rel="stylesheet"
+      media="print"
+      onload="this.media='all'"
+    />
+    <noscript>
       <link
         href="https://fonts.googleapis.com/icon?family=Material+Icons"
         rel="stylesheet"
       />
+    </noscript>
     <meta name="msvalidate.01" content="5AF60C1471E1800B39DF4DBC3C709035" />
   </head>
   <body>