Policybazaar 和 JioHotstar 如何使用 Translator 和 Language Detector API 打造多語言體驗

// Language Detector and Translator APIs implemented with React
import { useRef } from "react";

const useService = () => {
  const languageModel = useRef(null);
  const translatorCapabilitiesModel = useRef(null);
  const loadAllModels = async () => {
    if (window?.LanguageDetector) {
      languageModel.current = await window.LanguageDetector.create().catch(() => null);
    }
  }

  // Detect what language the customer is writing
  const detectLanguage = async (message) => {
    if (!languageModel.current) return "";
    try {
      const [result] = await languageModel.current.detect(message);
      const { detectedLanguage, confidence } = result || {};
      return confidence * 100 > 50 ? detectedLanguage : "";
    } catch (err) {
      console.error(err);
      return "";
    }
  };

  // Translate messages to and from the detected language and English
  const translateMessage = async (message, detectedLanguage, targetLanguage = 'en') => {
    try {
      const modelAvailability = await window.Translator.availability({ sourceLanguage: detectedLanguage, targetLanguage });
      if (!['available', 'downloadable'].includes(modelAvailability)) {
        return message;
      }
      const translator = await window.Translator.create({ sourceLanguage: detectedLanguage, targetLanguage });
      const translatedMessage = await translator.translate(message);
      return translatedMessage;
    } catch (error) {
      return message;
    }
  }

  return { detectLanguage, translateMessage, loadAllModels };
}

export default useService;

// Initialize the translator, setting source and target languages
var translator = null;
var translatorAvailable = false;
var languageOptionsData = { name: "Hindi", code: "hi" };
var IGNORED_TEXT_NODES = ['RSI', 'NAV'];

function checkForLanguageOptions() {
  if (window.Translator) {
    translatorAvailable = true;
    return window.Translator.create({
      sourceLanguage: 'en',
      targetLanguage: languageOptionsData.code
    }).then(function (createdTranslator) {
      translator = createdTranslator;
    });
  } else {
    translatorAvailable = false;
    return Promise.resolve();
  }
}

/**
 * Translate the article content using the Translator API.
 * @param {HTMLElement} container - element that holds the article content.
 * @return {Promise<string>} A promise that resolves to the container's innerHTML after translation.
 */
function translateArticle(container) {
  if (!translatorAvailable) { return Promise.resolve(''); }

  var textNodes = getAllTextNodes(container);
  var promiseChain = Promise.resolve();

  textNodes.forEach(function (element) {
    if (IGNORED_TEXT_NODES.indexOf(element.nodeValue) !== -1) return;
    var message = element.nodeValue;
    promiseChain = promiseChain.then(function () {
      return translator.translate(message).then(function (translated) {
        element.nodeValue = translated;
      }).catch(function (error) {
        console.error('Translation error:', error);
      });
    });
  });

  return promiseChain.then(function () {
    return container.innerHTML;
  });
}

class SubTitleTranslator {
  // Cache translator instances based on source-target language pair, so that we don't create this often for multiple contents
  #translatorMap = {};
  // Get or create a translator for the language pair
  async #createTranslator(sourceLanguage, targetLanguage) {
    const key = `${sourceLanguage}-${targetLanguage}`;
    const translator = this.#translatorMap[key];
    // Check if a translator already exists for a language pair in the map
    if (translator) {
      return translator;
    }
    // Check if translation is available
    const isAvailable =
      (await Translator.availability({ sourceLanguage, targetLanguage })) ===
      "available";
    if (isAvailable) {
      // If available, create a new translator and cache it
      this.#translatorMap[key] = await Translator.create({
        sourceLanguage,
        targetLanguage,
      });
      return this.#translatorMap[key];
    }

    return null;
  }
  // Translate text
  async #translateText(text, sourceLanguage, targetLanguage) {
    const translator = await this.#createTranslator(
      sourceLanguage,
      targetLanguage
    );
    // Returns the given input text if translator is unavailable
    if (!translator) {
      return text;
    }
    return await translator.translate(text);
  }
  // Public method to get a reusable translation function for a specific language pair.
  getTranslatorFor(sourceLanguage, targetLanguage) {
    return async (text) => {
      try {
        return this.#translateText(text, sourceLanguage, targetLanguage);
      } catch {
        return text;
      }
    };
  }
}

const translatorFactory = new SubTitleTranslator();

/* Accept English input and translate to Tamil.*/
const translateToTamil = translatorFactory.getTranslatorFor('en','ta');

/* Accept English text as input and translate it to Japanese. */
const translateToJapanese = translatorFactory.getTranslatorFor('en','ja');

/* Accept English input and returns English, as `JTA` is not a valid language code. */
const translateToUnknownLanguage = translatorFactory.getTranslatorFor('en','jta');

/* updateSubtitle is the internal function that updates the rendered subtitle. */
translateToTamil('hi').then(result => updateSubtitle(result))
translateToJapanese('hi').then(result => updateSubtitle(result))
translateToUnknownLanguage('hi').then(result => updateSubtitle(result))