locale.py

import flask
import werkzeug
from teknologkoren_se_v2.translations import translations


def get_string(name):
    return translations[name][get_locale()]


def get_locale():
    lang_code = (flask.g.get('lang_code') or flask.session.get('lang_code'))

    if not lang_code:
        lang_code = flask.request.accept_languages.best_match(['sv', 'en'])

    return lang_code


def fix_missing_lang_code():
    if flask.g.get('lang_code') or flask.request.endpoint == 'static':
        # Lang code is not missing.
        return

    # If g.lang_code is not set, the lang code in path is probably
    # missing or misspelled/invalid.

    # Get a MapAdapter, the object used for matching urls.
    urls = flask.current_app.url_map.bind(
        flask.current_app.config['SERVER_NAME']
    )

    # Get whatever lang get_locale() decides (cookie or, if no cookie,
    # default), and prepend it to the requested path.
    proposed_lang = get_locale()
    new_path = proposed_lang + flask.request.path

    try:
        # Does this new path match any view?
        urls.match(new_path)
    except werkzeug.routing.RequestRedirect as e:
        # The new path results in a redirect.
        return flask.redirect(e.new_url)
    except (werkzeug.routing.MethodNotAllowed, werkzeug.routing.NotFound):
        # The new path does not match anything, we allow the request
        # to continue with the non-lang path. Probably 404. In case
        # this request results in something that does want a lang
        # code (error pages need it as main.html builds urls for the
        # nav), we set it to whatever was proposed by get_locale().
        # If we don't set it AND the client does not have lang saved
        # in a cookie, we'd get a 500.
        flask.g.lang_code = proposed_lang
        return None

    # The new path matches a view! We redirect there.
    return flask.redirect(new_path)


def url_for_other_lang(endpoint, view_args, fallback='index.index', **args):
    if get_locale() == 'sv':
        lang_code = 'en'
    else:
        lang_code = 'sv'

    if (endpoint and (flask
                      .current_app
                      .url_map
                      .is_endpoint_expecting(endpoint, 'lang_code'))):

        return flask.url_for(endpoint,
                             lang_code=lang_code,
                             **view_args or {},
                             **args)

    return flask.url_for(fallback,
                         lang_code=lang_code,
                         **view_args or {},
                         **args)