jQuery EasyUI 树形菜单 – 树形网格惰性加载节点

有时我们已经得到充分的分层树形网格（TreeGrid）的数据。
我们还想让树形网格（TreeGrid）按层次惰性加载节点。
首先，只加载顶层节点。
然后点击节点的展开图标来加载它的子节点。
本教程展示如何创建带有惰性加载特性的树形网格（TreeGrid）。

创建树形网格（TreeGrid）

    <table title=\"Folder Browser\" style=\"width:700px;height:300px\"
            data-options=\"
                url: \'data/treegrid_data.json\',
                method: \'get\',
                rownumbers: true,
                idField: \'id\',
                treeField: \'name\',
                loadFilter: myLoadFilter
            \">
        <thead>
            <tr>
                <th field=\"name\" width=\"220\">Name</th>
                <th field=\"size\" width=\"100\" align=\"right\">Size</th>
                <th field=\"date\" width=\"150\">Modified Date</th>
            </tr>
        </thead>
    </table>

为了放置加载子节点，我们需要为每个节点重命名 \’children\’ 属性。
正如下面的代码所示，\’children\’ 属性重命名为 \’children1\’。
当展开一个节点时，我们调用 \’append\’ 方法来加载它的子节点数据。

\’loadFilter\’ 代码

    function myLoadFilter(data,parentId){
        function setData(){
            var todo = [];
            for(var i=0; i<data.length; i++){
                todo.push(data[i]);
            }
            while(todo.length){
                var node = todo.shift();
                if (node.children){
                    node.state = \'closed\';
                    node.children1 = node.children;
                    node.children = undefined;
                    todo = todo.concat(node.children1);
                }
            }
        }
        
        setData(data);
        var tg = $(this);
        var opts = tg.treegrid(\'options\');
        opts.onBeforeExpand = function(row){
            if (row.children1){
                tg.treegrid(\'append\',{
                    parent: row[opts.idField],
                    data: row.children1
                });
                row.children1 = undefined;
                tg.treegrid(\'expand\', row[opts.idField]);
            }
            return row.children1 == undefined;
        };
        return data;
    }

下载 jQuery EasyUI 实例

jeasyui-tree-treegrid5.zip