easyui中tree使用simpleData的形式加载数据

了解了zTree的使用, 发现它的simpleData是非常好用的, 由后台返回一个扁平数据, 直接在前台解析成树形菜单, 网上查了一下, easyui也可以简单实现, 不过....没看懂, 先记录一下

<script type="text/javascript">
$(document).ready(function() {
    $("#tt").tree({
        url:"JsonString_zTree",
        checkbox:true,
        lines:true,
        dnd:true,
        parentField:"parentid",//必须
        textFiled:"menuName",//必须
        idFiled:"id",//必须
        onCheck:function(node, checked) {
            alert(node.id+" - "+node.text);
        }
    });
});

//easyui实现自定义simpleData加载
$.fn.tree.defaults.loadFilter = function (data, parent) {
    var opt = $(this).data().tree.options;
    var idFiled,
    textFiled,
    parentField;
    if (opt.parentField) {
        idFiled = opt.idFiled || 'id';
        textFiled = opt.textFiled || 'text';
        parentField = opt.parentField;
        
        var i,
        l,
        treeData = [],
        tmpMap = [];
        
        for (i = 0, l = data.length; i < l; i++) {
            tmpMap[data[i][idFiled]] = data[i];
        }
        
        for (i = 0, l = data.length; i < l; i++) {
            if (tmpMap[data[i][parentField]] && data[i][idFiled] != data[i][parentField]) {
                if (!tmpMap[data[i][parentField]]['children'])
                    tmpMap[data[i][parentField]]['children'] = [];
                data[i]['text'] = data[i][textFiled];
                tmpMap[data[i][parentField]]['children'].push(data[i]);
            } else {
                data[i]['text'] = data[i][textFiled];
                treeData.push(data[i]);
            }
        }
        return treeData;
    }
    return data;
}; 
</script>

后台返回的数据: 

[
　　{"id":"1","menuName":"我的工作台","parentid":"0"},
　　{"id":"10","menuName":"拓展计划","parentid":"7"},
　　{"id":"11","menuName":"广告完成计划","parentid":"8"},
　　{"id":"12","menuName":"销量完成计划","parentid":"8"},
　　{"id":"13","menuName":"省领导任务","parentid":"9"},
　　{"id":"14","menuName":"市县领导任务","parentid":"9"},
　　{"id":"15","menuName":"今日完成","parentid":"3"},
　　{"id":"2","menuName":"我的文档","parentid":"1"},
　　{"id":"3","menuName":"我的计划","parentid":"1"},
　　{"id":"4","menuName":"我的会议","parentid":"1"},
　　{"id":"5","menuName":"客户文档","parentid":"2"},
　　{"id":"6","menuName":"公司文档","parentid":"2"},
　　{"id":"7","menuName":"我的上班计划","parentid":"0"},
　　{"id":"8","menuName":"工作计划","parentid":"7"},
　　{"id":"9","menuName":"任务计划","parentid":"7"}
]