canonicalpath not the best way to find lang?

in https://docs.bolt.cm/2.2/howto/building-multilingual-websites#making-templates-and-fetching-content
we can find this :
{% if app.canonicalpath %}
{% set languageslug = app.canonicalpath|split('/')[1] %}
{% else %}
{% set languageslug = app.paths.current|split('/')[1] %}
{% endif %}

but it doesn't work if we host the site in a subfolder, like www.site.com/eventsite_subfolder/nl/index.php, as it will always return languageslug="eventsite_subfolder"

I'd rather use :
{% set languageslug = app.request.uri|split(paths.root)[1]|split("/")|first %}

ugly but works better :)