i18next-localforage-backend

Introduction

This is a i18next cache layer to be used in the browser using localforage as storage layer. It will load and cache resources from IndexedDB, webSQL or localStorage and can be used in combination with the chained backend.

Getting started

Source can be loaded via npm or downloaded from this repo.

• If you don't use a module loader it will be added to window.i18nextLocalForageBackend

# npm package
$ npm install i18next-localforage-backend

Wiring up with the chained backend:

import i18next from 'i18next';
import Backend from 'i18next-chained-backend';
import LocalforageBackend from 'i18next-localforage-backend'; // primary use cache
import XHR from 'i18next-xhr-backend'; // fallback xhr load
 
i18next
  .use(Backend)
  .init({
    backend: {
      backends: [
        LocalforageBackend,  // primary
        XHR                   // fallback
      ],
      backendOptions: [{
        /* below options */
      }, {
        loadPath: '/locales/{{lng}}/{{ns}}.json' // xhr load path for my own fallback
      }]
    }
  });

Cache Backend Options

var options = {
  // expiration
  expirationTime: 7*24*60*60*1000,
 
  // language versions
  versions: {},
 
  /**
  * Localforage specific options
  */
  
  // database name (prefix is using localStorage as storage driver)
  name: 'i18next_res',
 
  // The driver(s) to use, if multiple are provided, the first available is used
  driver: [localforage.INDEXEDDB, localforage.WEBSQL, localforage.LOCALSTORAGE],
  
  // when using IndexedDb is the dataStore name, when using WebSQL is the table name
  storeName: 'keyvaluepair',
  
  // DB schema version, used only in IndexedDB and WebSQL
  version: 1.0,
 
  // WebSQL only, database size in bytes
  size: 4980736,
 
  // description of the database, for developer usage
  description: '',
};

• Contrary to cookies behavior, the cache will respect updates to expirationTime. If you set 7 days and later update to 10 days, the cache will persist for 10 days

• Passing in a versions object (ex.: versions: { en: 'v1.2', fr: 'v1.1' }) will give you control over the cache based on translations version. This setting works along expirationTime, so a cached translation will still expire even though the version did not change. You can still set expirationTime far into the future to avoid this