PHP开发公众号时如何处理用户的交互与响应

//接收文本消息
$input = file_get_contents("php://input");
$xml = simplexml_load_string($input);
$fromUser = $xml->FromUserName; //发送消息的用户openid
$content = $xml->Content; //文本消息内容

//处理文本消息
switch ($content) {
    case '1':
        //回复文本消息
        $content = "您发送了数字1";
        echo generateReplyMessage($fromUser, $content);
        break;
    case '2':
        //回复图文消息
        echo generateNewsMessage($fromUser);
        break;
    default:
        //默认回复
        $content = "您发送了其他消息";
        echo generateReplyMessage($fromUser, $content);
        break;
}

//生成文本消息回复
function generateReplyMessage($toUser, $content) {
    $template = "<xml>
        <ToUserName><![CDATA[%s]]></ToUserName>
        <FromUserName><![CDATA[%s]]></FromUserName>
        <CreateTime>%s</CreateTime>
        <MsgType><![CDATA[text]]></MsgType>
        <Content><![CDATA[%s]]></Content>
    </xml>";
    $time = time();
    return sprintf($template, $toUser, $content, $time);
}

//生成图文消息回复
function generateNewsMessage($toUser) {
    $template = "<xml>
        <ToUserName><![CDATA[%s]]></ToUserName>
        <FromUserName><![CDATA[%s]]></FromUserName>
        <CreateTime>%s</CreateTime>
        <MsgType><![CDATA[news]]></MsgType>
        <ArticleCount>1</ArticleCount>
        <Articles>
            <item>
                <Title><![CDATA[PHP开发公众号]]></Title>
                <Description><![CDATA[利用PHP开发公众号]]></Description>
                <PicUrl><![CDATA[图片地址]]></PicUrl>
                <Url><![CDATA[跳转链接]]></Url>
            </item>
        </Articles>
    </xml>";
    $time = time();
    return sprintf($template, $toUser, $time);
}