catstodon/app/controllers/settings/preferences_controller.rb

# frozen_string_literal: true

class Settings::PreferencesController < Settings::BaseController
  def show; end

  def update
    if current_user.update(user_params)
      I18n.locale = current_user.locale
      redirect_to after_update_redirect_path, notice: I18n.t('generic.changes_saved_msg')
    else
      render :show
    end
  end

  private

  def after_update_redirect_path
    settings_preferences_path
  end

  def user_params
    params.require(:user).permit(:locale, chosen_languages: [], settings_attributes: UserSettings.keys)
  end
end