QNetworkRequest (HTTP GET) doesn't fire, after refactoring into a standalone class

Question

I've recently began the tedious process of modularising a large, monolithic audio player application that I wrote roughly 2 months ago.

This process is going reasonably well, although it appears that one of the methods (ScrobbleMedia - which predictably enough makes HTTP requests to submit information about a playing track to last.fm) no longer seems to make network requests.

However, the QUrl object that would be passed through to the QNetworkAccessManager instance/QNetworkRequest is being built correctly.

For comparison, a functional Mercurial revision of the code is available on BitBucket .

The ScrobbleMedia method currently looks like this, after refactoring:

#include "scrobblemedia.h"

#include <QDebug>
#include <cstdio>

ScrobbleMedia::ScrobbleMedia(QString asUsername, QString asPassword,
                         QString asArtist, QString asTrack, QString asAlbum)
{

    QString KEndPointURL = "http://lastfmstats.livefrombmore.com/universalscrobbler/scrobble.php";
    QUrl iScrobbleEndPoint(KEndPointURL);

      QNetworkAccessManager *iScrobbleDispatcher = new QNetworkAccessManager(this);


iScrobbleEndPoint.addQueryItem("submissionType","track");
iScrobbleEndPoint.addQueryItem("username", asUsername);
iScrobbleEndPoint.addQueryItem("password", asPassword);
iScrobbleEndPoint.addQueryItem("artist", asArtist);
iScrobbleEndPoint.addQueryItem("track", asTrack);
iScrobbleEndPoint.addQueryItem("album", asAlbum);
iScrobbleEndPoint.addQueryItem("number","1");
iScrobbleEndPoint.addQueryItem("duration","200");

iScrobbleDispatcher->get(QNetworkRequest(iScrobbleEndPoint));
connect(iScrobbleDispatcher, SIGNAL(finished(QNetworkReply*)),
 SLOT(replyFinished(QNetworkReply*)));

// QString Outside = iScrobbleEndPoint.toEncoded();

qDebug()  << "Received: " + 
  asUsername + " " + 
   asPassword + " " + 
    asArtist + " " +
     asTrack + " " + 
      asAlbum;

qDebug() << iScrobbleEndPoint.toString();

}

ScrobbleMedia::~ScrobbleMedia() {

}

The associated header file looks like:

#ifndef SCROBBLEMEDIA_H
#define SCROBBLEMEDIA_H

#include <QString>
#include <QtNetwork>
#include <QUrl>
#include <QNetworkAccessManager>



class ScrobbleMedia : public QObject
{
     Q_OBJECT;


private:

public:

    ScrobbleMedia(QString asUsername, QString asPassword, QString asArtist, QString asTrack, QString asAlbum);
    ~ScrobbleMedia();

};

#endif // SCROBBLEMEDIA_H

I'm currently building the application itself against a MinGW build of version 4.7.0 of the Qt libraries (included as part of Qt SDK 2010.05) under Windows 7 x86-64.

Any assistance would be appreciated.

Thanks in advance.

Answer 1

After reading a number of different sources of information (most of which were contradictory), I've found that the following results in a working solution - albeit with a cosmetic issue in the debugging output that doesn't seem to affect operation ( Object::connect: No such signal QNetworkReplyImpl::finished(QNetworkReply*) in ../AudioPlayer/scrobblemedia.cpp:29 ):

In scrobblemedia.cpp :

#include "scrobblemedia.h"

#include <QDebug>
#include <cstdio>

ScrobbleMedia::ScrobbleMedia(QString asUsername, QString asPassword,
                             QString asArtist, QString asTrack, QString asAlbum)
{

    QByteArray iDataSink;
    QEventLoop iLoop;

    QString KEndPointURL = "http://lastfmstats.livefrombmore.com/universalscrobbler/scrobble.php";
    QUrl iScrobbleEndPoint(KEndPointURL);

    iScrobbleEndPoint.addQueryItem("submissionType","track");
    iScrobbleEndPoint.addQueryItem("username", asUsername);
    iScrobbleEndPoint.addQueryItem("password", asPassword);
    iScrobbleEndPoint.addQueryItem("artist", asArtist);
    iScrobbleEndPoint.addQueryItem("track", asTrack);
    iScrobbleEndPoint.addQueryItem("album", asAlbum);
    iScrobbleEndPoint.addQueryItem("number","1");
    iScrobbleEndPoint.addQueryItem("duration","200");

    QNetworkAccessManager iScrobbleDispatcher;
    QNetworkRequest iScrobbleRequest(iScrobbleEndPoint);
    QNetworkReply *iScrobbleReply = iScrobbleDispatcher.get(iScrobbleRequest);

    QObject::connect(iScrobbleReply, SIGNAL(finished(QNetworkReply*)), &iLoop,
     SLOT(quit()));

    iDataSink = iScrobbleReply->readAll();

    qDebug()  << "Received: " + asUsername + " " + asPassword + " " + asArtist + " " + asTrack + " " + asAlbum;

    qDebug() << iScrobbleEndPoint.toString();

    iLoop.exec();
}

ScrobbleMedia::~ScrobbleMedia() {

}

void ScrobbleMedia::replyFinished(QNetworkReply*) {

}

void ScrobbleMedia::reallyDone() {

    qDebug() << "We've probably successfully Scrobbled...";
}

In scrobblemedia.h :

#ifndef SCROBBLEMEDIA_H
#define SCROBBLEMEDIA_H

#include <QString>
#include <QtNetwork>
#include <QUrl>
#include <QNetworkAccessManager>



class ScrobbleMedia : public QObject
{
     Q_OBJECT


private:


public:

    ScrobbleMedia(QString asUsername, QString asPassword, QString asArtist, QString asTrack, QString asAlbum);
    ~ScrobbleMedia();

private slots:
    void replyFinished(QNetworkReply*);
    void reallyDone();

};

#endif // SCROBBLEMEDIA_H

Thanks to everyone for their help.

Hopefully this code will serve as a useful template for others, in the future.