Language selector does not keep the current page but goes to the root of the website

[aleene]

What

A product page can often been seen in multiple languages. A drop-down menu allows to change the language of the page.

Steps to reproduce the behaviour

1. Go to https://hr.openfoodfacts.org/product/4020400898638/di-erbe-caramelle-vivil
2. Click on hrvatski to change to english
3. A main page is shown and not the product page in english

Expected behavior

A page in english

[hangy]

It works as implemented. 😅 Currently it's implemented to always go to the main page.

Because of the internationalized path parts, it's not easy to do. If we know that we're on a product page, then we could just assume that the English product will work, but if we're ie. on a 3rd level facet like https://jp.openfoodfacts.org/%E3%82%AB%E3%83%86%E3%82%B4%E3%83%AA%E3%83%BC/%E9%A3%B2%E6%96%99/%E3%83%A9%E3%83%99%E3%83%AB/eu%E3%82%AA%E3%83%BC%E3%82%AC%E3%83%8B%E3%83%83%E3%82%AF/%E3%83%A9%E3%83%99%E3%83%AB/en:pure-juice it gets more complicated as we need some canonical value available to build the URL in the "new" language. We already create a rel="canonical" URL, so adding that metadata somewhere should be possible.