Express-locales NPM

express-locales

Simple express middleware to determine language of request and populate it with locales.

Installation

This is a Node.js module available through the npm registry. Installation is done using the npm install command:

$ npm install express-locales

API

var expressLocales = require('express-locales');

app.use(expressLocales(options));

expressLocales(options)

Creates a middleware with specified options, then synchronously loads languages from options.supportedLanguages. Order for determining language is query -> cookie -> acceptLanguage -> default. Meaning query has most priority and default has lowest.

app.use(expressLocales({ defaultLanguage:"en", cookieName:"lang", queryName:"lang", supportedLanguages:["en"], directory:"./locales", writeMissing: true }))

Options

Function accepts these properties in the options object.

defaultLanguage

Specifies a language used as default when no cookie or query was found, or as fallback for unsupported languages.

cookieName

Specifies a name for cookie holding language name.

queryName

Specifies a name for query holding language name.

supportedLanguages

Specifies what languages can be used and will be loaded.

writeMissing

If this option is set to true and environment is not production, missing locales will be written into separate files.

req.translate(key, values) and res.locals.translate(key, values)

Retrieves a locale from file specific to language of request. key points to JSON key in locales file, like foo.bar. If key is not found, key will be returned instead.

app.get("/", (req, res) => {
	res.send(req.translate("foo.bar"));
});

// OR

app.get("/", (req, res) => {
	res.send(req.t("foo.bar"));
});

Placeholders

translate supports placeholders like {1} or {foo}. To replace a placeholder in locales file, specify values in values object. If no value is specified, placeholder will remain in string.

// Locales file
// {
//   "foo": "string with {bar} and {0}"
// }

app.get("/", (req, res) => {
	res.send(req.translate("foo", { bar: "bar" }));
});

// string with bar and {0}