Lang is a small library to handle language with key-value format.

Installing

For the latest version:

$ npm install @fendy3002/lang

Or using yarn:

$ yarn add @fendy3002/lang

Usage

This library accept a javascript object / json. Example of a language dictionary that can be supplied:

let dictionary = {
    "en": {
        "sales": {
            "create": {
                "created": "Your order has been created with number {order_id}",
                "customer_blocked": "Customer {customer} is blocked"
            },
            "delete": {
                "confirm": "Are you sure to delete order {order_id}?",
                "deleted": "Order has been deleted"
            }
        },
        "parameterized": "Age: {age}"
    }
};

The nested content can have more than 2 levels deep. To use the dictionary variable above (with async/await):

import langCore from '@fendy3002/lang';
let langSource = await langCore(dictionary);
let langEn = langSource.use("en");

let createdDefaultMessage = "Created successfully, order no: {order_id}";
let createdMessage = langEn._(
    "sales.create.created", 
    createdDefaultMessage, {
        order_id: "ORD/XII/1241"
    });

If you want to shorten / simplify the nested path, part method can be used:

let langSource = await langCore(dictionary);
let langEn = langSource.use("en");

let salesCreate = langEn.part("sales.create");
let createdDefaultMessage = "Created successfully, order no: {order_id}";
let createdMessage = langEn._(
    "created", 
    createdDefaultMessage, {
        order_id: "ORD/XII/1241"
    });

For the moment, to use parameter as replacement you can use {key} format, and supply the values as third parameter.

Express middleware

To use this library under express, it can be passed using middleware. For example, to use specific language dictionary using first segment of url (ex: http://example.com/en/sales/created):

let langSource = await langCore(dictionary);

app.use(":lang", (req, res, next) => {
    req.lang = langSource.use(req.params.lang);
});
app.get(":lang/sales/created", (req, res, next) => {
    let pageLang = req.lang.part("sales.create");
    let createdDefaultMessage = "Created successfully, order no: {order_id}";
    let createdMessage = pageLang._("created", createdDefaultMessage, {
        order_id: "ORD/XII/1241"
    });
});