Enable nested translations

src/plugins/piral-translate/src/create.test.ts

@@ -73,6 +73,22 @@ describe('Create Localize API', () => {
     expect(result).toEqual('bár');
   });
 
+  it('createApi can translate from local-global translations using the current language and passed nested translations', () => {
+    const config = {
+      language: 'en'
+    };
+    const api = (createLocaleApi(setupLocalizer(config))(context) as any)();
+    api.setTranslations({
+      en: {
+        header: {
+          title: 'Hello world'
+        }
+      }
+    });
+    const result = api.translate('header.title');
+    expect(result).toBe('Hello world');
+  });
+
   it('createApi falls back to standard string if language is not found', () => {
     const config = {
       language: 'en',

src/plugins/piral-translate/src/create.ts

@@ -4,7 +4,8 @@ import type { PiralPlugin } from 'piral-core';
 import { createActions } from './actions';
 import { Localizer } from './localize';
 import { DefaultPicker } from './default';
-import { PiletLocaleApi, LocalizationMessages, Localizable, PiralSelectLanguageEvent } from './types';
+import { PiletLocaleApi, LocalizationMessages, Localizable, PiralSelectLanguageEvent, NestedLocalizationMessages } from './types';
+import { flattenTranslations } from './flatten-translations';
 
 export interface TranslationFallback {
   (key: string, language: string): string;
@@ -22,7 +23,7 @@ export interface LocaleConfig {
    * Sets the default (global) localization messages.
    * @default {}
    */
-  messages?: LocalizationMessages;
+  messages?: LocalizationMessages | NestedLocalizationMessages;
   /**
    * Sets the default language to use.
    */
@@ -72,8 +73,8 @@ export function createLocaleApi(localizer: Localizable = setupLocalizer()): Pira
       let localTranslations: LocalizationMessages = {};
 
       return {
-        addTranslations(messages: LocalizationMessages[], isOverriding: boolean = true) {
-          const messagesToMerge: LocalizationMessages[] = messages;
+        addTranslations(messages, isOverriding = true) {
+          const messagesToMerge = messages;
 
           if (isOverriding) {
             messagesToMerge.unshift(localizer.messages);
@@ -100,7 +101,7 @@ export function createLocaleApi(localizer: Localizable = setupLocalizer()): Pira
           return selected;
         },
         setTranslations(messages) {
-          localTranslations = messages;
+          localTranslations = flattenTranslations(messages);
         },
         getTranslations() {
           return localTranslations;

src/plugins/piral-translate/src/flatten-translations.test.ts

@@ -0,0 +1,56 @@
+/**
+ * @vitest-environment jsdom
+ */
+import { describe, it, expect } from 'vitest';
+import { flattenTranslations } from './flatten-translations';
+
+describe('Flatten translations', () => {
+  it('flattenTranslations can handle flat keys', () => {
+    const messages = {
+      en: {
+        key: 'value'
+      },
+      fr: {
+        key: 'value (fr)'
+      }
+    };
+    const flatMessages = flattenTranslations(messages);
+    expect(flatMessages.fr.key).toEqual('value (fr)');
+  });
+
+  it('flattenTranslations can handle flat dot keys', () => {
+    const messages = {
+      en: {
+        'header.title': 'Hello world'
+      }
+    };
+    const flatMessages = flattenTranslations(messages);
+    expect(flatMessages.en['header.title']).toBe('Hello world');
+  });
+
+  it('flattenTranslations can handle nested keys', () => {
+    const messages = {
+      en: {
+        header: {
+          title: 'Hello world'
+        }
+      }
+    };
+    const flatMessages = flattenTranslations(messages);
+    expect(flatMessages.en['header.title']).toBe('Hello world');
+  });
+
+  it('flattenTranslations can handle nested keys with multiple depth levels', () => {
+    const messages = {
+      en: {
+        header: {
+          title: {
+            subtitle: 'Hello world'
+          }
+        }
+      }
+    };
+    const flatMessages = flattenTranslations(messages);
+    expect(flatMessages.en['header.title.subtitle']).toBe('Hello world');
+  });
+});

src/plugins/piral-translate/src/flatten-translations.ts

@@ -0,0 +1,46 @@
+import { LocalizationMessages, NestedLocalizationMessages } from './types';
+
+export function flattenTranslations(messages: LocalizationMessages | NestedLocalizationMessages): LocalizationMessages {
+  return Object.fromEntries(
+    Object
+      .entries(messages)
+      .map(([ language, translations ]) => {
+        return [
+          language,
+          flat(translations)
+        ]
+      })
+  );
+}
+
+function flat(source: Record<string, unknown>): Record<string, string> {
+  const target: Record<string, string> = {};
+
+  flatten(source, target);
+
+  return target;
+}
+
+function flatten(source: any, target: Record<string, string>, prop = '') {
+  if (typeof source === 'string') {
+    target[prop] = source;
+
+    return;
+  }
+
+  if (typeof source === 'object' && source !== null) {
+    Object
+      .keys(source)
+      .forEach((key) => {
+        flatten(
+          source[key],
+          target,
+          prop
+            ? `${prop}.${key}`
+            : key
+        );
+      });
+
+    return;
+  }
+}

src/plugins/piral-translate/src/localize.test.ts

@@ -8,6 +8,9 @@ const messages = {
   en: {
     hi: 'hello',
     greeting: 'Hi {{name}}, welcome back',
+    header: {
+      title: 'Hello world'
+    }
   },
   de: {
     hi: 'hallo',
@@ -76,4 +79,11 @@ describe('Localize Module', () => {
     const result = localizer.localizeGlobal('greeting', { name: undefined });
     expect(result).toBe('Hi , welcome back');
   });
+
+  it('localizeGlobal translates from global translations using passed nested translations', () => {
+    const localizer = new Localizer(messages, 'en');
+    const result = localizer.localizeGlobal('header.title');
+
+    expect(result).toBe('Hello world');
+  });
 });

src/plugins/piral-translate/src/localize.ts

@@ -1,4 +1,5 @@
-import { LocalizationMessages, Localizable } from './types';
+import { LocalizationMessages, Localizable, NestedLocalizationMessages } from './types';
+import { flattenTranslations } from './flatten-translations';
 
 function defaultFallback(key: string, language: string): string {
   if (process.env.NODE_ENV === 'production') {
@@ -20,15 +21,19 @@ function formatMessage<T extends object>(message: string, variables: T): string
 }
 
 export class Localizer implements Localizable {
+  public messages: LocalizationMessages;
+
   /**
    * Creates a new instance of a localizer.
    */
   constructor(
-    public messages: LocalizationMessages,
+    messages: LocalizationMessages | NestedLocalizationMessages,
     public language: string,
     public languages: Array<string>,
     private fallback = defaultFallback,
-  ) {}
+  ) {
+    this.messages = flattenTranslations(messages);
+  }
 
   /**
    * Localizes the given key via the global translations.

src/plugins/piral-translate/src/types.ts

@@ -100,6 +100,13 @@ export interface Translations {
   [tag: string]: string;
 }
 
+export interface NestedTranslations {
+  /**
+   * The available wordings (tag to translation or nested translations).
+   */
+  [tag: string]: string | NestedTranslations;
+}
+
 export interface LanguageLoader {
   (language: string, current: LanguageData): Promise<LanguageData>;
 }
@@ -119,6 +126,13 @@ export interface LocalizationMessages {
   [lang: string]: Translations;
 }
 
+export interface NestedLocalizationMessages {
+  /**
+   * The available languages (lang to wordings or nested wordings).
+   */
+  [lang: string]: NestedTranslations;
+}
+
 export interface PiletLocaleApi {
   /**
    * Adds a list of translations to the existing translations.
@@ -129,7 +143,7 @@ export interface PiletLocaleApi {
    * @param messagesList The list of messages that extend the existing translations
    * @param [isOverriding=true] Indicates whether the new translations overwrite the existing translations
    */
-  addTranslations(messagesList: LocalizationMessages[], isOverriding?: boolean): void;
+  addTranslations(messagesList: (LocalizationMessages | NestedLocalizationMessages)[], isOverriding?: boolean): void;
   /**
    * Gets the currently selected language directly.
    */
@@ -151,7 +165,7 @@ export interface PiletLocaleApi {
    * The translations will be exclusively used for retrieving translations for the pilet.
    * @param messages The messages to use as translation basis.
    */
-  setTranslations(messages: LocalizationMessages): void;
+  setTranslations(messages: LocalizationMessages | NestedLocalizationMessages): void;
   /**
    * Gets the currently provided translations by the pilet.
    */