อยากจะวนลูปให้ List select Menu ให้แสดงออกมาเหมือนดังตัวอย่างยังไงครับ มึนมากครับ

<div class="control-group">
           
             <label for="exampleSelect1">Parent</label>
            <div class="controls">
              <select id="sub_category" class="form-control" name="sub_category">
                <option></option> 
                <option value="0">Top Level Category</option>  
                <?php foreach ($categories as $cat): ?>
                <option value="<?php echo $cat['id']; ?>"><?php echo $cat['name']; ?></option>
                <?php endforeach; ?>
              </select>
            </div>
          </div>

$data['categories'] = $this->Category_admin->category_get_all();

public function category_create($post)
 {
	    $this->db->insert('categories', array('parent_id' => $post['sub_category'], 'name' => $post['name'],'detail' => $post['textarea'], 'date_added' => date("Y-m-d H:i:s"), 'date_edit' => date("Y-m-d H:i:s")));
		//$this->db->insert('category', array('parent_id' => $post['sub_category'], 'name' => $post['name'], 'description' => $post['textarea'], 'date_added' => date("Y-m-d H:i:s"), 'date_edit' => date("Y-m-d H:i:s") ));
	   
}

public function category_get_all($cat_id = 0)
    {   
        $this->data = array();
        $this->db->order_by('id', 'asc');
        $query = $this->db->get_where(categories, array('parent_id' => $cat_id));
        $counter = 0;
        foreach ($query->result() as $row) {
            $this->data[$counter]['id'] = $row->id;
            $this->data[$counter]['parent_id'] = $row->parent_id;
            $this->data[$counter]['name'] = $row->name;
            $this->data[$counter]['textarea'] = $row->detail;
            $this->data[$counter]['real_name'] = $row->name;
            $children = $this->category_get_children($row->id, ' - ', $counter);
			$counter = $counter + $children;
			$counter++;
        }        
        return $this->data;
    }
    
    public function category_get_children($id, $separator, $counter)
	{
        $this->db->order_by('id', 'asc');
		$query = $this->db->get_where(categories, array('parent_id' => $id));
		if ($query->num_rows() == 0)
		{
			return FALSE;
		}
		else
		{
			foreach($query->result() as $row)
			{
				$counter++;
				$this->data[$counter]['id'] = $row->id;
				$this->data[$counter]['parent_id'] = $row->parent_id;
                $this->data[$counter]['name'] = $separator.$row->name;
                $this->data[$counter]['textarea'] = $row->detail;
                $this->data[$counter]['real_name'] = $row->name;
				$children = $this->category_get_children($row->id, $separator.' - ', $counter);

				if ($children != FALSE)
				{
					$counter = $counter + $children;
				}
			}
			return $counter;
		}
	}