/**
 * 組裝選單資料（遞迴子選單）
 * @param Varien_Data_Tree_Node $node
 * @return array
 */
function nodeToArray(Varien_Data_Tree_Node $node) {
    $result = array();
    $result['category_id'] = $node->getId();
    $result['parent_id'] = $node->getParentId();
    $result['name'] = $node->getName();
    $result['url'] = Mage::helper('catalog/category')->getCategoryUrl($node);
    $result['is_active'] = $node->getIsActive();
    $result['position'] = $node->getPosition();
    $result['level'] = $node->getLevel();
    $result['children'] = array();
    foreach ($node->getChildren() as $child) {
        $result['children'][] = nodeToArray($child);
    }
    return $result;
}

/**
 * 獲取所有選單
 * @return array
 */
function load_tree() {
    $store = 1;
    $parentId = 1;
    $tree = Mage::getResourceSingleton('catalog/category_tree')->load();
    $root = $tree->getNodeById($parentId);
    if ($root && $root->getId() == 1) {
        $root->setName(Mage::helper('catalog')->__('Root'));
    }
    $collection = Mage::getModel('catalog/category')->getCollection()
        ->setStoreId($store)
        ->addAttributeToSelect('name')
        ->addAttributeToSelect('id')
        ->addAttributeToSelect('url')
//        ->addAttributeToSelect('is_active')
        ->addAttributeToFilter('include_in_menu',1) //include_in_menu為1表示nclude in Navigation Menu為YES
        ->addAttributeToFilter('is_active',1); //新增過濾條件,is_active為1表示啟用

    $tree->addCollectionData($collection, true);
    return nodeToArray($root);
}

function print_tree($tree, $level) {
    $level++;
    foreach ($tree as $item) {
        echo str_repeat("-", $level) . $item['name'] . '-' . $item['category_id'] . "";
        print_tree($item['children'], $level);
    }
}

$tree = load_tree();

var_export($tree['children'][0]['children']);