Introduction

This is an i18next backend to be used in Node.js and Deno. It will load resources from the file system.

It's based on the deprecated i18next-node-fs-backend and can mostly be used as a drop-in replacement.

It will load resources from filesystem. Right now it supports following filetypes:

• .json
• .json5
• .jsonc
• .yml/.yaml
• .js (very limited, checks for exports or export default)

Getting started

1# npm package
2$ npm install i18next-fs-backend

Wiring up:

1import i18next from 'i18next';
2import Backend from 'i18next-fs-backend';
3
4i18next.use(Backend).init(i18nextOptions);

for Deno:

1import i18next from 'https://deno.land/x/i18next/index.js'
2import Backend from 'https://deno.land/x/i18next_fs_backend/index.js'
3
4i18next.use(Backend).init(i18nextOptions);

• As with all modules you can either pass the constructor function (class) to the i18next.use or a concrete instance.

Backend Options

1{
2  // path where resources get loaded from, or a function
3  // returning a path:
4  // function(lngs, namespaces) { return customPath; }
5  // the returned path will interpolate lng, ns if provided like giving a static path
6  loadPath: '/locales/{{lng}}/{{ns}}.json',
7
8  // path to post missing resources
9  addPath: '/locales/{{lng}}/{{ns}}.missing.json',
10
11  // if you use i18next-fs-backend as caching layer in combination with i18next-chained-backend, you can optionally set an expiration time
12  // an example on how to use it as cache layer can be found here: https://github.com/i18next/i18next-fs-backend/blob/master/example/caching/app.js
13  // expirationTime: 60 * 60 * 1000
14}

Options can be passed in:

preferred - by setting options.backend in i18next.init:

1import i18next from 'i18next';
2import Backend from 'i18next-fs-backend';
3
4i18next.use(Backend).init({
5  backend: options,
6});

on construction:

1import Backend from 'i18next-fs-backend';
2const Backend = new Backend(null, options);

via calling init:

1import Backend from 'i18next-fs-backend';
2const Backend = new Backend();
3Backend.init(null, options);

TypeScript

To properly type the backend options, you can import the FsBackendOptions interface and use it as a generic type parameter to the i18next's init method, e.g.:

1import i18n from 'i18next'
2import FsBackend, { FsBackendOptions } from 'i18next-fs-backend'
3
4i18n
5  .use(FsBackend)
6  .init<FsBackendOptions>({
7    backend: {
8      // fs backend options
9    },
10
11    // other i18next options
12  })

If set i18next initImmediate option to false it will load the files synchronously

1// i18n.js
2const { join } = require('path')
3const { readdirSync, lstatSync } = require('fs')
4const i18next = require('i18next')
5const Backend = require('i18next-fs-backend')
6i18next
7  .use(Backend)
8  .init({
9    // debug: true,
10    initImmediate: false,
11    fallbackLng: 'en',
12    lng: 'en',
13    preload: readdirSync(join(__dirname, '../locales')).filter((fileName) => {
14      const joinedPath = join(join(__dirname, '../locales'), fileName)
15      const isDirectory = lstatSync(joinedPath).isDirectory()
16      return isDirectory
17    }),
18    ns: 'backend-app',
19    defaultNS: 'backend-app',
20    backend: {
21      loadPath: join(__dirname, '../locales/{{lng}}/{{ns}}.json')
22    }
23  })

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