Added preload option (#10)

bameyrick · Jan 30, 2025 · 1be87e7 · 1be87e7
1 parent 64b5e87
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diff --git a/packages/ng-lazy-translate/README.md b/packages/ng-lazy-translate/README.md
@@ -152,7 +152,7 @@ export class MyService {
 
 ## Dynamically adding translation asset paths
 
-You can dynamically add translation asset paths by calling the `addTranslationAssetPaths` method on the `LazyTranslateService`:
+You can dynamically add translation asset paths by calling the `addTranslationPaths` method on the `LazyTranslateService`:
 
 ```typescript
 import { LazyTranslateService } from '@qntm-code/ng-lazy-translate';
@@ -162,14 +162,26 @@ export class MyService {
   private readonly translateService = inject(LazyTranslateService);
 
   constructor() {
-    this.translateService.addTranslationAssetPaths({
+    this.translateService.addTranslationPaths({
       'en.home': 'assets/i18n/en/home.json',
       'fr.home': 'assets/i18n/fr/home.json',
     });
   }
 }
 ```
 
+You can also preload all the translation files in the current language by adding the `preload` paramater to the call:
+
+```typescript
+this.translateService.addTranslationPaths(
+  {
+    'en.home': 'assets/i18n/en/home.json',
+    'fr.home': 'assets/i18n/fr/home.json',
+  },
+  true
+);
+```
+
 ## LazyTranslateModuleConfig
 
 Whether you use the standalone components or the module, the LazyTranslateModuleConfig options are the same.
@@ -179,6 +191,7 @@ Whether you use the standalone components or the module, the LazyTranslateModule
 | defaultLanguage           | string                                          | The default language to use if no language is specified                                                           | Yes       | N/A                          |
 | languages                 | [Language[]](#language)                         | The list of languages to support                                                                                  | Yes       | N/A                          |
 | translationAssetPaths     | [TranslationAssetPaths](#translationassetpaths) | The list of translation assets to load. The key is the language and the translation file name.                    | No        | N/A                          |
+| preload                   | boolean                                         | Whether to preload all the translation files in the current language.                                             | No        | `false`                      |
 | useDefaultLanguage        | boolean                                         | Whether to use the default language if the specified language is not found                                        | No        | `true`                       |
 | enableLogging             | boolean                                         | Whether to enable logging of missing translations                                                                 | No        | `true`                       |
 | missingTranslationHandler | (language: string, key: string) => void         | A custom handler to use when a translation is not found. If not specified, the default handler will be used.      | No        | Will console.error a message |

diff --git a/packages/ng-lazy-translate/src/lib/models/translate-module-config.model.ts b/packages/ng-lazy-translate/src/lib/models/translate-module-config.model.ts
@@ -7,6 +7,7 @@ export interface LazyTranslateModuleConfig {
   languages: Language[];
   defaultLanguage: string;
   translationAssetPaths?: TranslationAssetPaths;
+  preload?: boolean;
   useDefaultLanguage?: boolean;
   enableLogging?: boolean;
   missingTranslationHandler?: MissingTranslationHandlerFn;

diff --git a/packages/ng-lazy-translate/src/lib/translate.service.spec.ts b/packages/ng-lazy-translate/src/lib/translate.service.spec.ts
@@ -229,4 +229,21 @@ describe(`LazyTranslateService`, () => {
       expect(result).toEqual({ test: 'test' });
     });
   });
+
+  describe('addTranslationPaths', () => {
+    it('should preload the translations if preload is true', () => {
+      const downloadFileSpy = jest.spyOn(service as never, 'downloadFile');
+
+      service.addTranslationPaths(
+        {
+          'en.common': 'assets/i18n/en/common.json',
+          'cy.common': 'assets/i18n/cy/common.json',
+        },
+        true
+      );
+
+      expect(downloadFileSpy).toHaveBeenCalledWith('en', 'common');
+      expect(downloadFileSpy).not.toHaveBeenCalledWith('cy', 'common');
+    });
+  });
 });
diff --git a/packages/ng-lazy-translate/src/lib/translate.service.ts b/packages/ng-lazy-translate/src/lib/translate.service.ts
@@ -57,7 +57,7 @@ export class LazyTranslateService {
     this.config = { useDefaultLanguage: true, enableLogging: true, ...config };
 
     if (this.config.translationAssetPaths) {
-      this.addTranslationPaths(this.config.translationAssetPaths);
+      this.addTranslationPaths(this.config.translationAssetPaths, this.config.preload);
     }
 
     this.defaultLanguage$ = new BehaviorSubject<string>(this.config.defaultLanguage);
@@ -82,8 +82,17 @@ export class LazyTranslateService {
   /**
    * Adds translation asset paths
    */
-  public addTranslationPaths(paths: TranslationAssetPaths): void {
-    Object.entries(paths).forEach(([key, value]) => this.translationAssetPaths.set(key, value));
+  public addTranslationPaths(paths: TranslationAssetPaths, preload?: boolean): void {
+    Object.entries(paths).forEach(([key, value]) => {
+      this.translationAssetPaths.set(key, value);
+      if (preload) {
+        const [language, namespace] = key.split('.');
+
+        if (language === this.language$.getValue()) {
+          this.downloadFile(language, namespace);
+        }
+      }
+    });
   }
 
   public setLanguage(language: string): void {