How to setup the middleware Service in nestJs application in nestjs-i18n package to get accept-language header without error? - localization

Question

Hey In my nestjs application, I have installed the nestjs-i18n npm package of version 10.2.6 . I have configured this I18nModule in the appModule as below :
app.module.ts :
import { MiddlewareConsumer, Module, NestModule } from '#nestjs/common';
import { ConfigModule } from '#nestjs/config';
import { PrismaModule } from './config/database';
import { SessionModule } from './modules/session/session.module';
import {
I18nModule,
QueryResolver,
AcceptLanguageResolver,
HeaderResolver,
} from 'nestjs-i18n';
import * as path from 'path';
import { I18nMiddleware } from './common/hooks/i18n/i18n.middleware';
#Module({
imports: [
PrismaModule,
SessionModule,
ConfigModule.forRoot({ isGlobal: true }),
I18nModule.forRoot({
fallbackLanguage: 'en',
fallbacks: {
'en-CA': 'fr',
'en-*': 'en',
'fr-*': 'fr',
pt: 'pt-BR',
},
loaderOptions: {
path: path.join(__dirname, '/i18n/'),
watch: true,
},
resolvers: [
{
use: QueryResolver,
options: ['lang'],
},
new HeaderResolver(['x-content-lang']),
AcceptLanguageResolver,
],
}),
],
controllers: [],
providers: [],
})
export class AppModule implements NestModule {
configure(consumer: MiddlewareConsumer) {
consumer.apply(I18nMiddleware).forRoutes('*');
}
}
I have also have the json files for multiple languages as below structure :
src Folder
|
|-i18n Folder
|
|--en Folder
|
|--en.json
| --fr Folder
|
| -- fr.json
| --etc
I have configured it in nest-cli.json as below :
nest-cli.json :
{
"$schema": "https://json.schemastore.org/nest-cli",
"collection": "#nestjs/schematics",
"sourceRoot": "src",
"compilerOptions": {
"assets": [
{
"include": "i18n/**/*",
"watchAssets":true
}
]
}
}
Problem :
I want to use the accept-language header to get the user-preferred language for translating the variables accordingly. So i have decided to implement the middleware to achieve it. But I don't know how to do it in the nestjs-i18n package .Please someone help me do this :
I hereby share the middleware i have written :
i18nMiddleware.ts :
import { Injectable, NestMiddleware } from '#nestjs/common';
import { FastifyRequest, FastifyReply } from 'fastify';
#Injectable()
export class I18nMiddleware implements NestMiddleware {
constructor() {}
async use(req: FastifyRequest, res: FastifyReply, next: () => void) {
const lang = req.headers['accept-language']?.toString();
console.log('............lang', lang);
if (lang) {
**// I want to what to write here to make the language received from the header**
}
next();
}
}
So please help me. Thanks in advance .