我需要添加此功能：
< ? php do_action('wpml_add_language_selector'); ?>
在XXXX所在的行：
<div class="selettore-lingua">XXXX</div>
但是我从PHP中得到一个错误，并且功能不起作用。有什么想法要解决吗？谢谢
case 'hmenu-center':
$this->html = '<div class="menu-wrapper'.$menu_sticky.$menu_no_arrow.$menu_sub_animation.' style-'.$stylemain.'-original">'.
($no_secondary !== 'on' ? $secondary_menu_html : '').
'<div class="navbar menu-secondary'.$stylemaincombo.$main_absolute.'">
<div class="menu-container-mobile '.$effects.$stylemainbackfull.'">
<div class="row-menu style-'.$stylemain.'-bg">
<div class="row-menu-inner">
<div id="logo-container-mobile" class="col-lg-0 logo-container">
<div id="main-logo" class="navbar-header style-'.$stylemain.'">'.$logoDiv.
'</div>
</div>
</div>
<div class="mmb-container">YO'.$woo_icon_mobile.
'<div class="mobile-menu-button '.$buttonstyle_primary.' lines-button x2"><span class="lines"></span>
</div>
</div>
</div>
</div>
</div>
<header id="masthead" class="navbar'.$stylemaincombo.'">
<div class="menu-container'.$effects.$stylemainbackfull.'">
<div class="row-menu'.$main_width.'">
<div class="row-menu-inner'.$stylemainback.'">
<div class="col-lg-12 main-menu-container middle">
<div class="menu-horizontal' . $sub_shadows . '">
<div class="menu-horizontal-inner">
'.
wp_nav_menu( array("menu" => $primary_menu,
"theme_location" => "primary",
"container" => "div",
"container_class" => "nav navbar-nav navbar-main " .
(($search !== '' || $cta_menu) ? 'navbar-nav-first' : 'navbar-nav-last') ,
"menu_class" => "menu-primary-inner menu-smart".(is_rtl() ? ' sm-rtl' : '')." sm",
"fallback_cb" => false,
"walker" => new wp_bootstrap_navwalker(),
"echo" => 0)
);
if ( $cta_menu ) {
$this->html .= wp_nav_menu( array(
"menu" => $cta_menu,
"theme_location" => "cta",
"container" => "div",
"container_class" => "nav navbar-nav navbar-cta" . ( ( $search === '' ) ? ' navbar-nav-last' : '' ),
"menu_class" => "menu-cta-inner menu-smart".(is_rtl() ? ' sm-rtl' : '')." sm",
"fallback_cb" => "wp_bootstrap_navwalker::fallback",
"walker" => new wp_bootstrap_navwalker(),
"echo" => 0)
);
}
$this->html .= ($search !== '' ? '<div class="nav navbar-nav navbar-nav-last">'.$search.'</div>' : '');
if ($no_secondary !== 'on') {
$this->html .= '<div class="desktop-hidden">
'.wp_nav_menu( array(
"menu" => $secondary_menu,
"theme_location" => "secondary",
"container" => "div",
"container_class" => "menu-accordion",
"menu_class" => "menu-smart".(is_rtl() ? ' sm-rtl' : '')." sm sm-vertical mobile-secondary-menu",
'fallback_cb' => false,
"walker" => new wp_bootstrap_navwalker(),
"echo" => 0)
).
'</div>';
}
$this->html .= '</div>
</div>
</div>
</div>
</div>
</div>
</header>
</div>';
break;
case 'hmenu-center-split':
global $logo_html;
$logo_html = '<div class="logo-container megamenu-diff middle">
<div id="main-logo" class="navbar-header style-'.$stylemain.'">
'.$logoDiv.'
</div>
<div class="mmb-container"><div class="mobile-menu-button '.$buttonstyle_primary.' lines-button x2"><span class="lines"></span></div></div>
</div>';
add_filter('wp_nav_menu_objects', 'uncode_center_nav_menu_items', 10, 2);
$this->html = '<div class="menu-wrapper'.$menu_shrink.$menu_sticky.$menu_no_arrow.$menu_sub_animation.'">
'.($no_secondary !== 'on' ? $secondary_menu_html : '').'
<header id="masthead" class="navbar'.$stylemaincombo.$main_absolute.' menu-with-logo">
<div class="menu-container'.$effects.$stylemainbackfull.'">
<div class="row-menu'.$main_width.'">
<div class="row-menu-inner'.$stylemainback.'">
<div id="logo-container-mobile" class="col-lg-0 logo-container megamenu-diff desktop-hidden">
<div class="navbar-header style-'.$stylemain.'">
'.$logoDiv.'
</div>
<div class="mmb-container">'.$woo_icon_mobile.'<div class="mobile-menu-button '.$buttonstyle_primary.' lines-button x2"><span class="lines"></span></div></div>
</div>
<div class="col-lg-12 main-menu-container middle">
<div class="menu-horizontal' . $sub_shadows . '">
<div class="menu-horizontal-inner">';
if ($social_html_inner !== '') {
$this->html .= '<div class="nav navbar-nav navbar-social navbar-nav-first">
<ul class="menu-smart'.(is_rtl() ? ' sm-rtl' : '').' sm menu-icons mobile-hidden tablet-hidden">
'.$social_html_inner.'
</ul>
</div>';
}
if ( $cta_menu ) {
$this->html .= wp_nav_menu( array(
"menu" => $cta_menu,
"theme_location" => "cta",
"container" => "div",
"container_class" => "nav navbar-nav navbar-cta hmenu-center-split-child" . ( ( $social_html_inner === '' ) ? ' navbar-nav-first' : '' ),
"menu_class" => "menu-primary-inner menu-smart".(is_rtl() ? ' sm-rtl' : '')." sm",
"fallback_cb" => "wp_bootstrap_navwalker::fallback",
"walker" => new wp_bootstrap_navwalker(),
"echo" => 0)
);
}
$this->html .= wp_nav_menu( array(
"menu" => $primary_menu,
"theme_location" => "primary",
"container" => "div",
"container_class" => "nav navbar-nav navbar-main",
"menu_class" => "menu-primary-inner menu-smart".(is_rtl() ? ' sm-rtl' : '')." sm",
"fallback_cb" => false,
"walker" => new wp_bootstrap_navwalker(),
"echo" => 0)
);
if ($search !== '') {
$this->html .= '<div class="nav navbar-nav navbar-nav-last">'.$search.'</div>';
}
if ($no_secondary !== 'on') {
$this->html .= '<div class="desktop-hidden">
'.wp_nav_menu( array(
"menu" => $secondary_menu,
"theme_location" => "secondary",
"container" => "div",
"container_class" => "menu-accordion",
"menu_class" => "menu-smart".(is_rtl() ? ' sm-rtl' : '')." sm sm-vertical mobile-secondary-menu",
'fallback_cb' => false,
"walker" => new wp_bootstrap_navwalker(),
"echo" => 0)
).
'</div>';
}
$this->html .= '</div>
</div>
</div>
</div>
</div>
</div>
</header>
</div>';
break;
case 'offcanvas_head':
$this->html = '<div class="menu-wrapper'.$menu_shrink.$menu_sticky.'">
<div id="masthead" class="navbar'.$stylemaincombo.$main_absolute.' menu-with-logo">
<div class="menu-container'.$effects.$stylemainbackfull.'">
<div class="row-menu row-offcanvas'.$main_width.'">
<div class="row-menu-inner row-brand menu-horizontal-inner'.$stylemainback.'">';
if ($param == 'menu-overlay-center' && $search !== '') {
$this->html .= '<div class="nav navbar-nav navbar-nav-first">
'.$search.'
</div>';
}
$this->html .= '<div id="logo-container-mobile" class="col-lg-0 logo-container middle"><div class="selettore-lingua">XXXX</div>
<div id="main-logo" class="navbar-header style-'.$stylemain.'">
'.$logoDiv.'
</div>
</div>
<div class="mmb-container">'.$woo_icon_mobile.'<div class="'.(($param == 'menu-overlay' || $param == 'menu-overlay-center') ? 'mobile-menu-button menu-button-overlay no-toggle' : 'mobile-menu-button menu-button-offcanvas').' '.$buttonstyle_primary.' lines-button x2 trigger-overlay" '.(($param == 'menu-overlay' || $param == 'menu-overlay-center') ? 'data-area="menu" data-container="main-container"' : '').'><span class="lines"></span></div></div>';
if ( $cta_menu ) {
$this->html .= '<div class="col-lg-12 main-menu-container cta-container middle' . $menu_sub_animation . $menu_no_arrow . '">
<div class="menu-horizontal' . $sub_shadows . '">
<div class="menu-horizontal-inner">
'.wp_nav_menu( array(
"menu" => $cta_menu,
"theme_location" => "cta",
"container" => "div",
"container_class" => "nav navbar-nav navbar-cta",
"menu_class" => "menu-cta-inner menu-smart".(is_rtl() ? ' sm-rtl' : '')." sm",
"fallback_cb" => "wp_bootstrap_navwalker::fallback",
"walker" => new wp_bootstrap_navwalker(),
"echo" => 0)
).
'</div>
</div>
</div><!-- .main-menu-container -->';
}
$this->html .= '</div>
</div>
</div>
</div>
</div>';
break;