Qtwebkit persistence Cookie is not working - qt

Question

I am trying to implement a persistence in a Qtwebkit based browser for section keeping. I have extended QNetworkCookieJar. I didn't override any file but only added a save and load function. The functions is called explisitly.
I am getting the following error. The code is taken from brower code in Qt5.1 example.
QVariant::save: unable to save type 'QList<QNetworkCookie>' (type id: 1038).
Am I doing any thing wrong.. Please Help...Attaching my implementation of QNetworkCookie is bellow
static const unsigned int JAR_VERSION = 23;
#if 1
QT_BEGIN_NAMESPACE
QDataStream &operator<<(QDataStream &stream, const QList<QNetworkCookie> &list)
{
stream << JAR_VERSION;
stream << quint32(list.size());
for (int i = 0; i < list.size(); ++i)
stream << list.at(i).toRawForm();
return stream;
}
QDataStream &operator>>(QDataStream &stream, QList<QNetworkCookie> &list)
{
list.clear();
quint32 version;
stream >> version;
if (version != JAR_VERSION)
return stream;
quint32 count;
stream >> count;
for(quint32 i = 0; i < count; ++i)
{
QByteArray value;
stream >> value;
QList<QNetworkCookie> newCookies = QNetworkCookie::parseCookies(value);
if (newCookies.count() == 0 && value.length() != 0) {
qWarning() << "CookieJar: Unable to parse saved cookie:" << value;
}
for (int j = 0; j < newCookies.count(); ++j)
list.append(newCookies.at(j));
if (stream.atEnd())
break;
}
return stream;
}
QT_END_NAMESPACE
#endif
CookieJar::CookieJar(QObject *parent)
: QNetworkCookieJar(parent)
{
load();
}
CookieJar::~CookieJar()
{
save();
}
void CookieJar::load()
{
QSettings cookieSettings("./cookies_dir/Browser/cookies.ini", QSettings::IniFormat);
setAllCookies(qvariant_cast<QList<QNetworkCookie> >(cookieSettings.value(QLatin1String("cookies"))));
}
void CookieJar::save()
{
// purgeOldCookies();
QString directory = "./cookies_dir/Browser";
if (!QFile::exists(directory)) {
QDir dir;
dir.mkpath(directory);
}
QSettings cookieSettings(directory + QLatin1String("/cookies.ini"), QSettings::IniFormat);
QList<QNetworkCookie> cookies = allCookies();
qWarning("\n\n+=======================================================+\n\n");
for (int i = cookies.count() - 1; i >= 0; --i) {
qWarning()<< cookies.at(i).domain();
qWarning()<< cookies.at(i).name();
if (cookies.at(i).isSessionCookie())
cookies.removeAt(i);
}
qWarning("\n\n+=======================================================+\n\n");
cookieSettings.setValue(QLatin1String("cookies"), QVariant::fromValue<QList<QNetworkCookie> >(cookies));
}
void CookieJar::purgeOldCookies()
{
QList<QNetworkCookie> cookies = allCookies();
if (cookies.isEmpty())
return;
int oldCount = cookies.count();
QDateTime now = QDateTime::currentDateTime();
for (int i = cookies.count() - 1; i >= 0; --i) {
if (!cookies.at(i).isSessionCookie() && cookies.at(i).expirationDate() < now)
cookies.removeAt(i);
}
if (oldCount == cookies.count())
return;
setAllCookies(cookies);
}
bool CookieJar::setCookiesFromUrl(const QList<QNetworkCookie> &cookieList, const QUrl &url)
{
qWarning()<< url;
return QNetworkCookieJar::setCookiesFromUrl(cookieList, url);
}
I have registered the CookieJar using bellow code.
jar = new CookieJar(this);
webView->page()->networkAccessManager()->setCookieJar(jar);

Answer 1

You must call qRegisterMetaTypeStreamOperators<QList<QNetworkCookie>>("QList<QNetworkCookie>") before saving or loading to QSettings.

Answer 2

You need to use qRegisterMetaTypeStreamOperators and defines stream operators.
Here is an example save QList< QNetworkCookie> type cookies. In the header declares stream operators :
class cookieJar: public QNetworkCookieJar
{
bool save(const QUrl& url);
bool load(const QUrl& url);
}
QDataStream &operator<<(QDataStream &out, const QNetworkCookie &cookie);
QDataStream &operator>>(QDataStream &in, QNetworkCookie &cookie);
In cpp file you do something like:
CookieJar::CookieJar(QObject* parent) :
QNetworkCookieJar(parent)
{
qRegisterMetaTypeStreamOperators<QNetworkCookie>("QNetworkCookie");
}
bool CookieJar::save(const QUrl &url)
{
QList<QNetworkCookie> cookies = cookiesForUrl(url);
QSettings cookieSettings;
for(auto cookie : cookies)
{
cookieSettings.setValue(cookie.name(), QVariant::fromValue(cookie));
}
}
bool CookieJar::load(const QUrl &url)
{
QSettings cookieSettings;
// empty list created here
QList<QNetworkCookie> cookies;
// retrieve all keys from cookies.ini
QStringList keys = cookieSettings.allKeys();
for(auto key: keys)
{
QNetworkCookie cookie = qvariant_cast<QNetworkCookie>(cookieSettings.value(key, QVariant()));
cookies.append(cookie);
}
setCookiesFromUrl(cookies, url);
return true;
}
QDataStream &operator<<(QDataStream &out, const QNetworkCookie &cookie)
{
out << cookie.toRawForm();
}
QDataStream &operator>>(QDataStream &in, QNetworkCookie &cookie)
{
QByteArray raw_data;
in >> raw_data;
QList<QNetworkCookie> cookies = QNetworkCookie::parseCookies(raw_data);
cookie = cookies.at(0);
}