def get_dir_from_zipfile(zip_file, fallback=None):
    """Return the name of the root folder in a zip file.

    :param zip_file: a :class:`zipfile.ZipFile` instance.
    :param fallback: if `None`, the name of the zip file is used. This is
        returned if the zip file contains more than one top-level directory,
        or none at all.
    """
    fallback = fallback or zip_file.filename
    directories = [name for name in zip_file.namelist() if name.endswith("/")
                   and len(PurePath(name).parts) == 1]
    return fallback if len(directories) > 1 else directories[0]
def settings(slug=None):
    slug = slug if slug else "general"

    # get the currently active group
    active_group = SettingsGroup.query.filter_by(key=slug).first_or_404()
    # get all groups - used to build the navigation
    all_groups = SettingsGroup.query.all()

    SettingsForm = Setting.get_form(active_group)

    old_settings = Setting.get_settings(active_group)
    new_settings = {}

    form = SettingsForm()

    if form.validate_on_submit():
        for key, values in iteritems(old_settings):
            try:
                # check if the value has changed
                if values['value'] == form[key].data:
                    continue
                else:
                    new_settings[key] = form[key].data
            except KeyError:
                pass
        Setting.update(settings=new_settings, app=current_app)
        flash(_("Settings saved."), "success")
    else:
        for key, values in iteritems(old_settings):
            try:
                form[key].data = values['value']
            except (KeyError, ValueError):
                pass

    return render_template("management/settings.html", form=form,
                           all_groups=all_groups, active_group=active_group)