Description

The i18n module for Nest.

Installation

$ npm i --save nestjs-i18n

Quick Start

Structure

create a directory and in it define your language keys as directories. When using BY_LANGUAGE you can also define global translations. This is useful for things that are the same in each language for example your company name. Each file that is in the root of your i18n folder will be defined globally. You can overwrite global translations by defining them within a language.

i18n
├── en
│   ├── category.json
│   └── auth.json
├── nl
│   ├── category.json
│   └── auth.json
└── global.json

Translation file

The format for the translation file could look like this:

{
  "HELLO_MESSAGE": "Hello {username}",
  "GOODBYE_MESSAGE": "Goodbye {username}",
  "USER_ADDED_PRODUCT": "{0.username} added {1.productName} to cart",
  "SETUP": {
    "WELCOME": "Welcome {0.username}",
    "GOODBYE": "Goodbye {0.username}"
  },
  "ARRAY": [
    "ONE",
    "TWO",
    "THREE"
  ]
}

String formatting is done by: string-format

Translation module

To use the translation service we first add the module. The I18nModule has an @Global() attribute so you should only import it once.

import { Module } from '@nestjs/common';
import * as path from 'path';
import { I18nModule } from 'nestjs-i18n';

@Module({
  imports: [
    I18nModule.forRoot({
      path: path.join(__dirname, '/i18n'), 
      filePattern: '*.json',
      fallbackLanguage: 'en',
    }),
  ],
  controllers: []
})
export class AppModule {}

using forRootAsync

import { Module } from '@nestjs/common';
import * as path from 'path';
import { I18nModule } from 'nestjs-i18n';

@Module({
  imports: [
    I18nModule.forRootAsync({ 
        useFactory: (config: ConfigurationService) => ({ 
          path: configService.i18nPath, 
          fallbackLanguage: configService.fallbackLanguage, // e.g., 'en'
          filePattern: configService.i18nFilePattern, // e.g., '*.i18n.json'
        }),
        inject: [ConfigurationService] 
    }),
  ],
  controllers: []
})
export class AppModule {}

Using translation service

@Controller()
export class SampleController {

  constructor(
    private readonly i18n: I18nService,
  ) {}

  @Get()
  sample() {
    this.i18n.translate('en', 'HELLO_MESSAGE', {id: 1, username: 'Toon'});
    this.i18n.translate('en', 'SETUP.WELCOME', {id: 1, username: 'Toon'});
    this.i18n.translate('en', 'ARRAY.0');
  }
}

Breaking changes:

from V3.0.0 on we load translations based on their directory name instead of file name. Change your translations files to the structure above: info

sergey-telpuk/nestjs-i18n