PHPを使って公開アカウントのキーワード返信機能を開発する方法

function getAccessToken($appid, $appsecret){
    $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=".$appid."&secret=".$appsecret;
    $result = httpGet($url);
    $accessToken = json_decode($result, true)['access_token'];
    return $accessToken;
}

function httpGet($url){
    $curl = curl_init();
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($curl, CURLOPT_TIMEOUT, 500);
    curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
    curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, false);
    curl_setopt($curl, CURLOPT_URL, $url);
    $result = curl_exec($curl);
    curl_close($curl);
    return $result;
}

$appid = "Your App ID";
$appsecret = "Your App Secret";
$accessToken = getAccessToken($appid, $appsecret);

$data = file_get_contents("php://input");
$message = simplexml_load_string($data, 'SimpleXMLElement', LIBXML_NOCDATA);
$msgType = $message->MsgType;
$keyword = trim($message->Content);
$reply = "";

if ($msgType == "text") {
    if ($keyword == "你好") {
        $reply = "你好，欢迎关注我们的公众号！";
    } elseif ($keyword == "最新消息") {
        $reply = "这里是最新消息！";
    } else {
        $reply = "感谢您的留言，我们会尽快回复您！";
    }
}

$response = "<xml>
<ToUserName><![CDATA[" . $message->FromUserName . "]]></ToUserName>
<FromUserName><![CDATA[" . $message->ToUserName . "]]></FromUserName>
<CreateTime>" . time() . "</CreateTime>
<MsgType><![CDATA[text]]></MsgType>
<Content><![CDATA[" . $reply . "]]></Content>
</xml>";

echo $response;