function getJsSign()
{
if ($this->request->is('post')) {
$url = $this->request->data('url');
$timestamp = $this->request->data('timestamp');
$nonceStr = $this->request->data('nonceStr');
$appId = 'yourappid';
$wxObj = new Wechat(array('token' => 'yourtoken', 'appid' => $appId, 'appsecret' => 'yourpants'));
//调用对应的函数
$sign = $wxObj->getJsSign($url, $timestamp, $nonceStr);
//如果token失效，清除token重试一次
if ($wxObj->errCode == 40001 || $wxObj->errCode == 42001) {
$wxObj->resetAuth();
$sign = $wxObj->getJsSign();
}
//如果返回false，获取errcode和errmsg
if (!$sign) {
return $this->sentJson(array('errCode' => $wxObj->errCode, 'errMsg' => WechatErrCode::getErrText($wxObj->errCode)));
}
$package = array('signature' => $sign, 'nonceStr' => $nonceStr, 'appId' => $appId, 'timestamp' => $timestamp);
return $this->sentJson(array('errCode' => 0, 'errMsg' => '', 'result' => $package));
}
}