intlayer Express Middleware Documentation

The intlayer middleware for Express detects the user's locale and provides translation functions via the res.locals object. It also enables the use of the t and getIntlayer functions throughout your request handlers.

Usage

import express from "express";
import { intlayer } from "express-intlayer";

const app = express();

app.use(intlayer());

app.get("/", (req, res) => {
  const content = res.locals.t({
    "en-GB": "Hello",
    en: "Hello",
    fr: "Bonjour",
  });

  res.send(content);
});

Description

The middleware performs the following tasks:

1. Locale Detection: It checks cookies, headers (such as Accept-Language), and URL parameters to determine the user's locale.
2. Context Setup: It populates res.locals with:
   • locale: The detected locale.
   • t: A translation function bound to the detected locale.
   • getIntlayer: A function to retrieve dictionaries bound to the detected locale.
3. Async Local Storage: It sets up a context that allows the use of global t and getIntlayer functions imported from express-intlayer within the request flow.