Hi all,

I'm having some problems with QNetworkAccessManager (qt 4.5.2, windows 7). i try to develop a simple widget that is supposed to connect to google calendar. Basically all functionality is a set of post() and request() function calls to the appropriate google calendar urls. While this basically works, i get random http errors at random points of execution, and i cant seem to find out whats wrong.

my current code is supposed to do a 'login', consisting of 3 requests:
1) post() username & password to login url
* receive authorization token, use this for all following requests
2) get() to calendar list url, to receive a list of calendars
* receive calender list
3) get() to event list url
* receive event list

sometimes, all steps are executed, and sometimes i get http400/Bad Request, http 399/Data corrupted or even http status code 0 along with an empty reply at random points. now, i think it might have something to do with the fact that i fire requests in QNetworkAccessManager's finished() slot, but i dont know how to do it right.

now for some code:

Qt Code: 
  1. MainClass::MainClass()
  2. {
  3.    lastRequest = 0;
  4.    manager = new QNetworkAccessManager(this);
  5.    connect(manager, SIGNAL(authenticationRequired(QNetworkReply*,QAuthenticator*)), this, SLOT(onAuthenticationRequired(QNetworkReply*,QAuthenticator*)));
  6.    connect(manager, SIGNAL(finished(QNetworkReply*)), this, SLOT(onFinished(QNetworkReply*)));
  7.    connect(manager, SIGNAL(proxyAuthenticationRequired(QNetworkProxy,QAuthenticator*)), this, SLOT(onProxyAuthenticationRequired(QNetworkProxy,QAuthenticator*)));
  8.    connect(manager, SIGNAL(sslErrors(QNetworkReply*,QList<QSslError>)), this, SLOT(onSslErrors(QNetworkReply*,QList<QSslError>)));
  9.  
  10. ...
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prepare Requests:
Qt Code: 
  1. int MainClass::prepare(const QString& url)
  2. {
  3.    delete lastRequest;
  4.    lastRequest = new QNetworkRequest(QUrl(url));
  5.  
  6.    if (!authToken.isEmpty())
  7.    {
  8.       lastRequest->setRawHeader("Authorization", authToken);
  9.       lastRequest->setRawHeader("GData-Version", "2");
  10.    }
  11.  
  12.    return success;
  13. }
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do login:

Qt Code: 
  1. int MainClass::login(const QString& aEmail, const QString& aPassword)
  2. {
  3.    DataPacket data;             // request body
  4.  
  5.    prepare(urls[urlLogin]);     // s.o.
  6.  
  7.    /* prepare body */
  8.  
  9.    manager->post(*lastRequest, data.getData() /* == QByteArray */);
  10.  
  11.    return success;
  12. }
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the other requests are simple GETs on the apropriate feed-urls:

Qt Code: 
  1. int MainClass::getCalendarList()
  2. {
  3.    ...
  4.    /* some error checks */
  5.  
  6.    prepare(urls[urlCalendarListFull]);
  7.  
  8.    manager->get(*lastRequest);
  9.  
  10.    return success;
  11. }
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finished-slot:

Qt Code: 
  1. void MainClass::onFinished(QNetworkReply* reply)
  2. {
  3.    int statusCode = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();
  4.  
  5.    qDebug() << "FINISHED" << statusCode;
  6.  
  7.    switch (statusCode)
  8.    {
  9.       case 200:                               // OK
  10.       {
  11.          // process reply
  12.  
  13.          if (!isLoggedIn())
  14.             storeAuthorization(reply);
  15.  
  16.          switch (state)
  17.          {
  18.             case stGetCalendars:
  19.             {
  20.                parseCalendarList(reply);
  21.                break;
  22.             }
  23.             case stGetEvents:
  24.             {
  25.                parseEventList(reply);
  26.                break;
  27.             }
  28.          }
  29.  
  30.          break;
  31.       }
  32.  
  33.       case 302:                               // redirect (Location: [URL])
  34.       {
  35.          qDebug() << "redirected to" << locationOf(reply);
  36.          prepare(locationOf(reply));
  37.          manager->get(*lastRequest);
  38.  
  39.          break;
  40.       }
  41.  
  42.       case 400:                               // bad request
  43.       {
  44.          QMessageBox::warning(this, "Error", "Network error (HTTP400/Bad Request)");
  45.          break;
  46.       }
  47.  
  48.       case 403:                               // permission denied
  49.       {
  50.          QMessageBox::warning(this, "Permission denied", "Username or password invalid");
  51.          break;
  52.       }
  53.  
  54.       default:
  55.       {
  56.          QByteArray replyData = reply->readAll();
  57.          qDebug() << "Unknown response" << replyData;
  58.          break;
  59.       }
  60.    }
  61.  
  62.    reply->deleteLater();
  63.  
  64.    // do anything afterwards?
  65.  
  66.    after();            // <-- next request via manager->get()
  67.  
  68.    qDebug() << "request done";
  69. }
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does someone know what might be wrong?