嵌套排序不能在codeigniter中工作

Question

我跟随系列在tutlus上的codeigniter中构建了一个cms。

当我点击保存按钮时，我收到错误：$（...）。nestedSortable不是函数

控制器：

public function order() {
    $this->data['sortable'] = true;
    $this->data['subview'] = 'admin/page/order';
    $this->load->view('admin/_layout_main', $this->data);

}

public function order_ajax() {
    // Fetch all pages
    $this->data['pages'] = $this->page_m->get_nested();

    // Load view
    $this->load->view('admin/page/order_ajax', $this->data);    
}

型号：

public function get_nested () {
    $pages = $this->db->get('pages')->result_array();

    $array = array();
    foreach ($pages as $page) {
        if(!$page['parent_id']) {
            $array[$page['id']] = $page;
        } else {
            $array[$page['parent_id']]['children'][] = $page;
        }
    }
    return $array;
}

查看：order.php

<section>
<h2>Order pages</h2>
<p class="alert alert-info">Drag to order pages and then click 'Save'</p>
<div id="orderResult"></div>
<input type="button" id="save" value="Save" class="btn btn-primary" />
</section>

<script>
$(function() {
$.post('<?php echo site_url('admin/page/order_ajax'); ?>', {}, function(data) {
    $('#orderResult').html(data);
});

$('#save').click(function() {
    oSortable = $('.sortable').nestedSortable('toArray');
    $.post('<?php echo site_url('admin/page/order_ajax'); ?>', { sortable: oSortable },         function(data) {
        $('#orderResult').html(data);
    });
});
});
</script>

order_ajax.php：

<?php
echo get_ol($pages);

function get_ol ($array, $child = FALSE ) {

 $str = '';

 if(count($array)) {
    $str .= $child == FALSE ? '<ol class="sortable">' : '<ol>';   

    foreach ($array as $item) {
         $str .= '<li id="list_' . $item['id'] .'">';
        $str .= '<div>' . $item['title'] . '</div>';
    //Do we have any Children?
        if(isset($item['children']) && count($item['children'])) {
        $str .= get_ol($item['children'], TRUE);
        }

        $str .= '</li>' . PHP_EOL;
    }

$str .= '</ol>' . PHP_EOL;
}

return $str;
}
?>

<script type="text/javascript">

$(document).ready(function(){

    $('.sortable').nestedSortable({
        handle: 'div',
        items: 'li',
        toleranceElement: '> div', 
        maxLevels: 2
    });

});   

</script>

我在头页中包含了jquery，jquery-ui，jquery.nested文件。