[req|res].setLocale() doesn't change template locale

app.use(i18n.init) sets res.locals.locale so that the template helpers can get the current language. However, calling res.setLocale() doesn’t update this property, so the final page language doesn’t get changed.

// First Request:
app.use(i18n.init); // locale=en, res.locals.locale=en
app.use(function(req, res, next) {
  res.setLocale('ja'); // locale=ja, res.locals.locale=en
  res.render('some-template'); // template i18n helpers use locals.locale, 
                               // so page is still in english
});

// Second Request:
app.use(i18n.init); // locale = ja, res.locals.locale=ja
// ...

I’m not sure what the right fix is here (or even if you consider this bug), but I thought I’d open this up to start a discussion.

[mauron85]

I had same/similar issue. I solved it by manually setting res.locals.language to same locale as in req.setLocale fnc.

app.use(function (req, res, next) {
    var locale = 'en';
    req.setLocale(locale);
    res.locals.language = locale;
});

Hope it helps.

[FredKSchott]

Yea sure, it’s small enough to include here:

var http = require('http'),
    express = require('express'),
    i18n = require('i18n');

i18n.configure({
    locales: ['ja', 'en'],
    cookie: 'lang',
    directory: 'locales/'
});

var app = express();

app.use(i18n.init);

app.use(function(req, res, next) {
    res.setLocale('ja');
    next();
});

app.use(function(req, res, next) {
    console.log(res.getLocale()); // ja
    console.log(res.locale); // en
    console.log(req.locale); // ja
    console.log(res.locals); // { locale: en, /* ... */ }
    next();
});

var server = http.createServer(app);
server.listen(3000);

This is slightly different behavior than my application (not sure where my undefineds are coming from) but it looks like that same hbs template helper problem would be occurring here as well