Get current locale in Jinja2

Question

On my website use Flask + Jinja2, and Flask-Babel for translation. The site has two languages (depending on the URL), and I'd want to add a link to switch between them. To do this correctly I need to get the name of the current locale, but I didn't find such function in the docs. Does it exist at all?

Answer 1

Finally, I used this solution: add get_locale function, which should be defined anyway, to Jinja2 globals, and then call it in template like any other function.

Answer 2

Other answers say that you must implement the babel's get_locale() function and that you should add it to Jinja2 globals, but they don't say how. So, what I did is:

I implemented the get_locale() function as follows:

from flask import request, current_app

@babel.localeselector
def get_locale():
    try:
        return request.accept_languages.best_match(current_app.config['LANGUAGES'])
    except RuntimeError:  # Working outside of request context. E.g. a background task
        return current_app.config['BABEL_DEFAULT_LOCALE']

Then, I added the following line at my Flask app definition:

app.jinja_env.globals['get_locale'] = get_locale

Now you can call get_locale() from the templates.

Answer 3

You are responsible to store the user's locale in your session on database. Flask-babel will not do this for you, so you should implement get_locale method for flask-babel to be able to find your user's locale.

This is an example of get_locale from flask-babel documentation:

from flask import g, request

@babel.localeselector
def get_locale():
    # if a user is logged in, use the locale from the user settings
    user = getattr(g, 'user', None)
    if user is not None:
        return user.locale
    # otherwise try to guess the language from the user accept
    # header the browser transmits.  We support de/fr/en in this
    # example.  The best match wins.
    return request.accept_languages.best_match(['de', 'fr', 'en'])