Wordpress导航步行器计数子菜单

Question

在WordPress菜单中，我需要在父级<li>有3级时（当父级的子菜单也有子菜单时）将其添加到父级<ul> <li>Parent <ul class="sub-menu"> <li>Sublink1</li> <li>Sublink2</li> </ul> </li> <li>Parent</li> <li class="mega">Parent <!-- add class here b/c it has 3 levels --> <ul class="sub-menu"> <li>Sublink1</li> <li>Sublink2</li> <li>Sublink3 <ul class="sub-menu"> <li>Sublink1</li> <li>Sublink2</li> </ul> </li> </ul> </li> <li>Parent</li> <li>Parent</li> <li>Parent <ul class="sub-menu"> <li>Sublink1</li> <li>Sublink2</li> </ul> </li> </ul> 。换句话说：

//store the last visited row
var row = false;

// save the row if has changed
function save () {
    if (row.changed){
        console.log("save");
    }
}

// keep track of the row you are in
// it doesnt work when you leave the table
$("tr").on("focusin", function (e) {
    if (row != this){
        if (row){
            save();
        }
        row = this;
        e.stopPropagation();
    }
});

//keep track whenever the row changes
$("tr").on("change", function (e) {
    this.changed = true;
    console.log("changed");
})

//triggers when you leave the table, you can try to save changes then.
$(document).on("focusin", function (e) {
    var el = $(e.target); //input or element that triggers this event
    var elrow = el.parent().parent()[0]; // try to get the row from that input, ... if its an input
    if (row && row !=elrow) {
        save();
        e.stopPropagation();
    };
})

我确定我需要使用Walker来实现这一目标，但我无法找到一个像这样做的例子。谢谢！