Yii AJAX CTreeView 實現動態加載無限級樹 代碼

--   
-- 表的結構 `coverage`   
--   
CREATE TABLE IF NOT EXISTS `coverage` (   
 `id` int(10) unsigned NOT NULL AUTO_INCREMENT,   
 `pid` int(10) unsigned DEFAULT NULL,   
 `coverageName` varchar(100) DEFAULT NULL,   
 `coverageDesc` varchar(200) DEFAULT NULL,   
 PRIMARY KEY (`id`),   
 KEY `pid` (`pid`)   
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=20 ;   
--   
-- 轉存表中的數據 `coverage`   
--   
INSERT INTO `coverage` (`id`, `pid`, `coverageName`, `coverageDesc`) VALUES   
(16, NULL, '類別', ''),   
(17, 16, '類別一', ''),   
(18, NULL, '分類', ''),   
(19, 17, '類別二', '');   
--   
-- 限制表 `coverage`   
--   
ALTER TABLE `coverage`   
 ADD CONSTRAINT `coverage_ibfk_1` FOREIGN KEY (`pid`) REFERENCES `coverage` (`id`) ON DELETE CASCADE;

然後才Controller中添加下面的代碼：
 

public function actionAjaxFillTree()   
{   
    if (!Yii::app()->request->isAjaxRequest) {   
    exit();   
    }   
    $parentId = 'null';   
    if (isset($_GET['root']) and $_GET['root']!='source') {   
        $parentId = (int) $_GET['root'];   
    }   
    $req = Yii::app()->db->createCommand(   
        "SELECT m1.id, m1.coverageName AS text, m2.id IS NOT NULL AS hasChildren "
        . "FROM coverage AS m1 LEFT JOIN coverage AS m2 ON m1.id=m2.pid "
        . "WHERE m1.pid <=> $parentId "
        . "GROUP BY m1.id ORDER BY m1.coverageName ASC"
    );   
    $children = $req->queryAll();   
    echo str_replace(   
    '"hasChildren":"0"',   
    '"hasChildren":false',   
    CTreeView::saveDataAsJson($children),   
    );   
    exit();   
}

然後在views中添加如下代碼：

$this->widget('CTreeView',array(   
     'persist'=>'cookie',   
     'animated'=>'fast',   
     'url' => array('ajaxFillTree'),   
     'htmlOptions'=>array(   
     'id'=>'coverageTree',   
     'class'=>'coverageTree'
     )   
 ));

done!