wordpress简易手风琴折叠菜单

html部分
<ul class="side_menu">
    <?php wp_nav_menu( array( 'theme_location' => 'side', 'menu_class' => 'nav-menu','container' => false,'items_wrap' => '%3$s' ) ); ?>
</ul>
jquery部分
        function appendIcon(){
            var iconp = '<i class="fa fa-plus" aria-hidden="true"></i>';
            var iconm = '<i class="fa fa-minus" aria-hidden="true"></i>';
            $('.side_menu > li').append(iconp,iconm);            
        }
        appendIcon();
        $('.side_menu .menu-item-has-children .fa').click(function(){
            $(this).parent().find('.sub-menu').toggle();
        });
        $('.side_menu .current-menu-item').addClass('active_menu');
        $('.side_menu > li').click(function(){
            $(this).toggleClass('active_menu');
        });
css部分
.side_menu li{
    font-family: 'PTSansBold';
    margin-bottom: 0 !important;
    position: relative;    
}
.side_menu li a{
    padding: 10px 20px;
    display: inline-block;
    width: 100%;
    border-bottom: 1px solid #666;
    background-color: #efefef;
    color: #242424;
    font-family: 'PTSansBold';
    font-size: 12px;
    text-transform: capitalize;
}
.side_menu li a:hover{
    background-color: rgb(204, 204, 204);
}
.side_menu .current-menu-item > a{
    background-color: rgb(204, 204, 204);
}
.side_menu i.fa {
    position: absolute;
    top: 11px;
    right: 11px;
    font-size: 14px;
    background-color: rgb(68, 67, 73);
    color: #fff;
    padding: 4px 6px;  
    transition: all ease 0.3s;
}
.side_menu i.fa:hover{
    background-color: #00418a;
    cursor: pointer;
}
.side_menu .sub-menu{
    display: none;
}
.side_menu .current-menu-item .sub-menu{
    display: block;
}
.side_menu .fa-plus{
    display: block;
}
.side_menu .fa-minus{
    display: none;
}
.active_menu .fa-plus{
    display: none;
}
.active_menu .fa-minus{
    display: block;
}
.side_menu .sub-menu li a{
    padding-left: 40px;
}