JS实现树形复选框级联选中

源码：

function getTreeSiblings(id){
    var tr = $("#"+id);
    var pId = tr.attr("pId");
    var siblings = [];
    if(pId != undefined){
        $("tr").each(function(i, ele) {
            tr = $(ele);
            if(tr.attr("pId") == pId){
                siblings.push($(this));
            }
        });
    }
    return siblings;
}
function getTreeParent(id){
    var tr = $("#"+id);
    var parents = [];
    parents.push(tr);

    var pId = tr.attr("pId");
    if(pId != undefined){parents = parents.concat(getTreeParent(pId));}
    return parents;
}        
function getTreeChildren(id){
    var tr = null;
    var children = [];
    if(id != undefined){
        $("tr").each(function(i, ele) {
            tr = $(ele);
            if(tr.attr("pId") == id){
                children.push(tr);
                children = children.concat(getTreeChildren(tr.find("input:eq(0)").val()));
            }
        });
    }
    return children;
}
function chkNode(obj) {
    var id = obj.value, chkbox = null;
    $.each(getTreeChildren(id), function(i,v){
        v.find("input:eq(0)").attr("checked", function(){return obj.checked ? "checked":""});
    });
    $.each(getTreeParent(id), function(i,v){
        if(i > 0){
            chkbox = v.find("input:eq(0)");
            chkbox.attr("checked", function(){return getTreeChildrenChecked(chkbox.val()) ? "checked":""});
        }
    });
}
function getTreeChildrenChecked(id){
    var chked = false;
    $.each(getTreeChildren(id), function(i,v){
        chked = v.find("input:eq(0)").attr("checked") == true;
        if(chked) {return false;}
    });
    return chked;
}