Language negotiation in Volto

Volto does not rely on the configuration set in Plone's Language Control Panel to handle the redirection from the root of the site to the Language Root Folder.

Volto has a setting in its own configuration stating whether a site is multilingual or not: isMultilingual.

First of all, you need to set that setting to true.

Then you need to add the list of supported languages to the supportedLanguages setting, and match them with the languages configured in Plone's Language Control Panel.

As a last thing, you need to set your site's defaultLanguage to one of the supportedLanguages.

When all these settings are configured, Volto's MultilingualRedirector will handle the language negotiation and the redirect.

In its configuration, the component tries to match the I18N_LANGUAGE cookie set in the user's browser with the list of supported languages, and if the match does not succeed, it selects the default language configured in Volto.

After that it does the redirection to the matched Language Root Folder.

If the site is not configured to be multilingual, Volto doesn't do any redirect.

Overriding the default behavior

To do so, you need to provide your own MultilingualRedirector component customizing it.