Qt network reply is empty - qnetworkrequest

Question

I know that this question has been asked many times however in my case the suggested codes and solutions aren't cutting it. The network reply is still my case empty and the error code is 0.
Here's my function:
QString NWork::send(QVector<QString> &data) const{
//QNetworkAccessManager qnam = new QNetworkAccessManager();
QNetworkAccessManager qnam;
try{
QString json = NWork::to_JSON(data);
QByteArray json_data(json.toUtf8());
QNetworkRequest request;
request.setUrl(QUrl(NWork::connection));
request.setRawHeader("Content-Type", "application/json");
request.setRawHeader("Content-Length", json_data);
reply = qnam.post(request, json_data);
//reply = qnam.get(request);
int status = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();
QString s(reply -> readAll());
qDebug()<<"code "<<status<<"Content "<<s;
//return QString::fromUtf8(response.data(),response.size());
}catch(std::exception x){
std::cout<<x.what()<<std::endl;
}
return "";
}
Making connections of the form suggested by many like
connect(qnam,SIGNAL(destroyed(QNetworkReply*)),this,SLOT(read(QNetworkReply*)));
have no effect on all. The request is reaching the PHP script and I know this by writing the request data in a file. It does so for every request. Echoing anything back even with a text/html header is not working.
Yes, I have tried my PHP script with a HTML AJAX request program and it works. It writes to file, and returns a response to the browser. Same code in both cases.
Here's my PHP code:
header("Access-Control-Allow-Origin: *");
$k = file_get_contents("php://input");
$file = "/file/path/log.k";
//echo $file;
$handle = fopen($file, "a+");
if($handle){
echo $k;
fwrite($handle, $k."\n");
fclose($handle);
}
header("Content-Type: text/html");
echo "line 22 ".$que;
exit(0);
I've checked my apache2 error logs and none are invoked. Why is it not working in my case?

Answer 1

I know this is almost a year old question but I just started teaching myself Qt and I recently ran into this issue as well and was bought to this page. So for those who are also stuck on this, here is how I solved it.
First change the connect from:
connect(qnam,SIGNAL(destroyed(QNetworkReply*)),this,SLOT(read(QNetworkReply*)));
to:
connect(reply, SIGNAL(finished()), this, SLOT(onReply()));
Then add it to your code after the post call like so:
reply = qnam.post(request, json_data);
connect(reply, SIGNAL(finished()), this, SLOT(onReply()));
The finished method is part of the QNetworkReply signals and is fired when the reply is finished. The method inside of SLOT is a Q_SLOT that you have to define in your hpp. Then move your code to your onReply method it would look similar to this:
QNetworkReply* reply = qobject_cast<QNetworkReply*>(sender());
QString response = reply->readAll();
if (reply)
{
if (reply->error() == QNetworkReply::NoError)
{
const int available = reply->bytesAvailable();
if (available > 0)
{
const QByteArray buffer = reply->readAll();
response = QString::fromUtf8(buffer);
// success = true;
}
}
else
{
response = tr("Error: %1 status: %2").arg(reply->errorString(), reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toString());
}
qDebug()<<"code: "<<reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toString()<<" response: "<<response;
reply->deleteLater();
}
sources: QNetworkReply, BlackBerry Sample App Maven source code