treegrid控件应用（拖拽）

一、数据

看到这样的前端控件，我最先关心的是数据是如何存储的。这里以json为例，贴一个来自官网的样例json文件：

第一类：

[{"id":1,"name":"C","size":"","date":"02/19/2010","type":"folder","children":[{"id":2,"name":"Program Files","size":"120 MB","date":"03/20/2010","type":"folder","children":[{"id":21,"name":"Java","size":"","date":"01/13/2010","state":"closed","type":"folder","children":[{"id":211,"name":"java.exe","size":"142 KB","date":"01/13/2010","type":"pack"},{"id":212,"name":"jawt.dll","size":"5 KB","date":"01/13/2010","type":"pack"}]},{"id":22,"name":"MySQL","size":"","date":"01/13/2010","state":"closed","type":"folder","children":[{"id":221,"name":"my.ini","size":"10 KB","date":"02/26/2009","type":"pack"},{"id":222,"name":"my-huge.ini","size":"5 KB","date":"02/26/2009","type":"pack"},{"id":223,"name":"my-large.ini","size":"5 KB","date":"02/26/2009","type":"pack"}]}]},{"id":3,"name":"eclipse","size":"","date":"01/20/2010","type":"folder","children":[{"id":31,"name":"eclipse.exe","size":"56 KB","date":"05/19/2009","type":"pack"},{"id":32,"name":"eclipse.ini","size":"1 KB","date":"04/20/2010","type":"pack"},{"id":33,"name":"notice.html","size":"7 KB","date":"03/17/2005","type":"pack"}]}]}]

2..{"total":7,"rows":[    {"id":1,"name":"All Tasks","begin":"3/4/2010","end":"3/20/2010","progress":60,"iconCls":"icon-ok"},    {"id":2,"name":"Designing","begin":"3/4/2010","end":"3/10/2010","progress":100,"_parentId":1,"state":"closed"},    {"id":21,"name":"Database","persons":2,"begin":"3/4/2010","end":"3/6/2010","progress":100,"_parentId":2},    {"id":22,"name":"UML","persons":1,"begin":"3/7/2010","end":"3/8/2010","progress":100,"_parentId":2},    {"id":23,"name":"Export Document","persons":1,"begin":"3/9/2010","end":"3/10/2010","progress":100,"_parentId":2},    {"id":3,"name":"Coding","persons":2,"begin":"3/11/2010","end":"3/18/2010","progress":80},    {"id":4,"name":"Testing","persons":1,"begin":"3/19/2010","end":"3/20/2010","progress":20}],"footer":[    {"name":"Total Persons:","persons":7,"iconCls":"icon-sum"}]}

可以根据_parentId来确定它的父节点。

二、使用

调用treegrid有两种方式，第一种直接使用HTML配置，第二种用JS配置。

官网上贴的

<table id="tt" class="easyui-treegrid" style="width:600px;height:400px"        data-options="url:'get_data.php',idField:'id',treeField:'name'">    <thead>        <tr>            <th data-options="field:'name',width:180">Task Name</th>            <th data-options="field:'persons',width:60,align:'right'">Persons</th>            <th data-options="field:'begin',width:80">Begin Date</th>            <th data-options="field:'end',width:80">End Date</th>        </tr>    </thead></table>

第二种：

HTML中：

<table id="tt" style="width:600px;height:400px"></table>

JS中：

$('#tt').treegrid({    url:'get_data.php',    idField:'id',    treeField:'name',    columns:[[        {title:'Task Name',field:'name',width:180},        {field:'persons',title:'Persons',width:60,align:'right'},        {field:'begin',title:'Begin Date',width:80},        {field:'end',title:'End Date',width:80}    ]]});

注意：我在使用的时候发现了一些问题，情况可能比较特殊。最好使用最新的easyui文件，我用旧版本的文件，结果不认table标签中的data-option属性。对于使用第一种配置方法的童鞋，如果没有加载进入数据的话，可尝试手动加载：

$.post('treegrid.json',function(data){                $('#test2').treegrid('loadData',data);                },'json');

treegrid.json是你的json数据文件，相对地址。

三、拓展

treegrid支持很多功能可以自己定义，官网上有官网DEMO
下边记录一下我在使用拖拽功能时候遇到的问题：

treegrid支持拖拽的官方DEMO

让treegrid支持拖拽还需要treegrid-dnd.js  。这个文件中定义了拖拽相关的接口函数，文件不大，读起来应该问题不大。

1. 禁止drop

在我的需求中，叶子节点是不可以拖到叶子节点上的，demo中，如果把叶子节点放在叶子节点上的话，目标节点就会自动变为被拖动节点的父节点，与我的需求不符合。修改treegrid-dnd.js中的onDrop函数，在onDrop的时候判断是否叶子节点，是的话就返回：

var dest = this;var action, point;var tr = opts.finder.getTr(target, $(this).attr('node-id'));var dRow = getRow(this);var sRow = getRow(source);//alert("destination:"+dRow.type+",source:"+sRow.type)if(dRow.type=="pack"){tr.removeClass('treegrid-row-append treegrid-row-top treegrid-row-bottom');return;}

上边代码中，dRow.type是自定义的，type是我的json数据中的一个属性，来标识是否是叶子节点。

2. 节点处于编辑状态下禁止拖拽

需求中有要求可以修改节点的名字，编辑列中editor="text"，进入编辑状态后变为textbox，如果想使用鼠标选中内容的话就会触发拖动事件，因此在编辑的时候要禁止拖拽。

但是treegrid-dnd.js 中没有禁止拖拽的接口，只有enableDnd。查了好多没有查到禁止的用法，而且官网上提供的方法也只有enableDnd。那么就参考enableDnd的写法，自已写一个disableDnd好了：

$.extend($.fn.treegrid.methods, {disableDnd:function(jq,id){return jq.each(function() {var target = this;var state = $.data(this, 'treegrid');state.disabledNodes = [];var t = $(this);var opts = state.options;if (id) {var nodes = opts.finder.getTr(target, id);var rows = t.treegrid('getChildren', id);for (var i = 0; i < rows.length; i++) {nodes = nodes.add(opts.finder.getTr(target, rows[i][opts.idField]));}} else {var nodes = t.treegrid('getPanel').find('tr[node-id]');}nodes.draggable({disabled: true,revert: true,cursor: 'pointer'});});}});

我在调用拖拽的时候是配置的table的data-option，这里也要修改：

<table id="dndtree" title="Folder Browser" class="easyui-treegrid" style="width:700px;height:250px"data-options="url:'treegrid.json',rownumbers: false,idField: 'id',treeField: 'name',onContextMenu:onContextMenu,onLoadSuccess: function(row){$(this).treegrid('enableDnd', row?row.id:null);},                onBeforeEdit: function(row){                    $(this).treegrid('disableDnd');                },                onAfterEdit: function(row){                    $(this).treegrid('enableDnd');                },                onCancelEdit: function(row){                    $(this).treegrid('enableDnd');                }"><thead><tr><th data-options="field:'name',formatter:formatName" width="220" editor="text">Name</th><th data-options="field:'size'" width="150" align="right">Size</th><th data-options="field:'date'" width="200">Modified Date</th></tr></thead></table>

onBeforeEdit时禁止拖拽，结束编辑或者取消编辑的时候再启用拖拽。