Why can't I parse the Cryptsy JSON API with Qt5/C++?

Question

I'm trying to parse this JSON Web-API using Qt5 and C++ using QJsonDocument and QJsonObject as seen here. But I fail to access the JSON value of the QJsonObject.

This is what I've tried so far:

// Contains the whole API as QString...
QString data = QString(reply->readAll());
// Reads the JSON as QJsonDocument...
QJsonDocument jsonResponse = QJsonDocument::fromJson(data.toUtf8());
// Reads the JSON as QJsonObject...
QJsonObject jsonObject = jsonResponse.object();

Now I have my object well prepared, but trying to access the values of the JSON somehow fails:

// This returns an empty string ""!?!
qDebug() << jsonObject.value("success").toString();

Well, maybe I got the keys wrong:

// Let's check the keys...
QStringList stringList = jsonObject.keys();
for (QStringList::Iterator it = stringList.begin(); it != stringList.end(); ++it)
{
    // This returns "success" and "return" - huh!?!
    qDebug() << *it;
}

OK, the keys are veryfied, why is it not working?

// Let's check the values by using the keys directly...
for (QStringList::Iterator it = stringList.begin(); it != stringList.end(); ++it)
{
    // This returns empty strings "" and "" - now what?!?
    qDebug() << jsonObject.value(*it).toString();
}

This again, makes no sense at all. I can't see why I can not access the value of the JSON object by the keys. Any idea?

I tried exactly the same code on other JSON APIs (for example this one) without any issues. I am totally stuck here.

user3408714 · Accepted Answer · 2014-07-09 20:17:08Z

Here's my solution for Qt5 Json parsing the Cryptsy API.

QEventLoop loopEvent;
QNetworkAccessManager namMNGR;
QObject::connect(&namMNGR, SIGNAL(finished(QNetworkReply*)), &loopEvent, SLOT(quit()));
QNetworkRequest req(QUrl(QString("http://pubapi.cryptsy.com/api.php?method=singlemarketdata&marketid=%1").arg(marketID)));
QNetworkReply *reply = namMNGR.get(req);
loopEvent.exec();
//Json API parsing begins.
QString jsonSTR = reply->readAll();
if (!(reply->error() == QNetworkReply::NoError)) {
    delete reply; //API Connection Problem.
}
QJsonDocument jsonDocument = QJsonDocument::fromJson(jsonSTR.toUtf8());
QJsonObject obj1 = jsonDocument.object();
QJsonValue val1 = obj1.value(obj1.keys().first());
QJsonObject obj2 = val1.toObject();
QJsonValue val2 = obj2.value(obj2.keys().first());
QJsonObject obj3 = val2.toObject();
QJsonValue marketDataValue = obj3.value(obj3.keys().first());
QJsonObject marketDataObject = marketDataValue.toObject();
QJsonArray sellordersArray = marketDataObject["sellorders"].toArray();

Have you managed to get Authenticated POST API data from Qt5? I'm trying to figure out how to do it.

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