CodeIgniter典型的表单提交验证代码

<?php echo form_open('user/reg'); ?>
    <h5>用户名</h5>
    <input type="text" name="username" value="<?php echo $this->validation->username;?>" size="50" />
    <span id="error_msg"><?php echo $this->validation->username_error; ?></span>

    <h5>密码</h5>
    <input type="password" name="password"  size="50" />
    <span id="error_msg"><?php echo $this->validation->password_error; ?></span>

    <h5>确认密码</h5>
    <input type="password" name="passconf"  size="50" />
    <span id="error_msg"><?php echo $this->validation->passconf_error; ?></span>

    <h5>Email</h5>
    <input type="text" name="email" value="<?php echo $this->validation->email;?>" size="50" />
    <span id="error_msg"><?php echo $this->validation->email_error; ?></span>
    <div><input type="submit" value="Submit" /></div>

    </form>

$this->load->library('validation');
$this->load->helper('form');

$rules['username'] = "trim|required|min_length[5]|max_length[16]|xss_clean|callback_username_check";
$rules['password'] = "trim|required|matches[passconf]|md5";
$rules['passconf'] = "trim|required";
$rules['email'] = "trim|required|valid_email|callback_email_check";
$this->validation->set_rules($rules);

$fields['username'] = '用户名';
$fields['password'] = '密码';
$fields['passconf'] = '密码确认';
$fields['email'] = '邮箱地址';
$this->validation->set_fields($fields);

if ($this->validation->run() == FALSE)
{
    $this->load->view('user/reg_view');
}
else
{
    //调用这个函数保存数据到数据库
    $this->user_model->reg();
    $this->load->view('user/reg_suc_view');
}

$activation_key = md5(uniqid() + time());
$data = array
(
    'username' => $this->input->post('username'),
    'password' => $this->input->post('password'),
    'email' => $this->input->post('email'),
    'registered_date' => time(),
    'activation_key' => $activation_key,
    'status'=>0,
    'level'=>0,
    'reserve_times'=>0,
    'credit'=>0,
);

$this->db->insert($this->config->item('db_prefix').'user', $data);