How to make slot work at time when calling function? - c++

Question

I have a function and connection between a slot and a signal.
Check the code below:
void NetworkAccessManager::sendPOST(QString url)
{
QNetworkCookieJar *cookieJar = new QNetworkCookieJar(manager_);
manager_->setCookieJar(cookieJar);
QNetworkRequest request(url);
QByteArray postData;
postData.append("j_username=admin&");
postData.append("j_password=admin");
manager_->post(request, postData);
connect(manager_, SIGNAL(finished(QNetworkReply *)), this, SLOT(replyFinishedSlot(QNetworkReply *)));
}
void NetworkAccessManager::replyFinishedSlot(QNetworkReply *reply)
{
...
cookie = "...";
}
Code above owned by class NetworkAccessManager. Variable cookie is public and I need to change its value in replyFinishedSlot.
I try to use the function sendPOST() in constructer of another class and it works, but slot doing nothing and cookie varaible is empty. What do I do wrong?
Here's the code inside another class:
NetworkAccessManager *manager = new NetworkAccessManager();
manager->sendPOST("http://example.com");
qDebug() << "cookies: " << manager->cookies;
I guess that slot may not work because I never emit signal finished(), but I am not sure where should I emit this because my code shouldn't work with the user interface.

Answer 1

I have found a couple of problem solutions.
First one
I am saving the cookie in a file. Here's the code:
void NetworkAccessManager::replyFinishedSlot(QNetworkReply *reply)
{
...
QFile cookieFile("cookie.txt");
if (cookieFile.open(QIODevice::WriteOnly))
{
cookieFile.write(cookies.toUtf8());
cookieFile.close();
}
...
}
Here's the constructer of class where I use the function
NetworkAccessManager *manager = new NetworkAccessManager();
manager->sendPOST("http://example.com");
QString cookies = "";
QFile cookieFile("cookie.txt");
if (cookieFile.exists() && cookieFile.open(QIODevice::ReadOnly))
{
cookies = cookieFile.readAll();
cookieFile.close();
}
QMap<QString, QString> elements;
elements.insert("cookies", cookies);
Second one
I use a signal to send the info to QML (I transferred my NetworkAccessManager class to WebViewModel).
.h
class WebViewModel : public QObject
{
Q_OBJECT
public:
explicit WebViewModel(QObject *parent = nullptr);
~WebViewModel();
void sendPOST(QString url);
private slots:
void replyFinishedSlot(QNetworkReply *);
private:
QNetworkAccessManager *manager_;
signals:
void finished(QNetworkReply *);
void cookieReady(QString thisCookie);
};
.cpp
WebViewModel::WebViewModel(QObject* parent)
: QObject(parent)
{
manager_ = new QNetworkAccessManager(this);
sendPOST("http://example.com");
}
WebViewModel::~WebViewModel()
{
delete manager_;
}
void WebViewModel::sendPOST(QString url)
{
...
connect(manager_, SIGNAL(finished(QNetworkReply *)), this, SLOT(replyFinishedSlot(QNetworkReply *)));
...
}
void WebViewModel::replyFinishedSlot(QNetworkReply *reply)
{
if(reply->error())
{
...
}
else
{
...
QString cookieString = cookie[0].name() + "=" + cookie[0].value() + "; domain=" + cookie[0].domain() + "; path=" + cookie[0].path();
emit cookieReady(cookieString);//the signal sends my variable to .qml
...
}
}
.qml
Connections {
target: WebViewModel
onCookieReady: {
testCookies = thisCookie
//thisCookie variable wasn't declared in the .qml file, thisCookie variable
//is accessible by signal void cookieReady(QString thisCookie) from .h C++
//and MUST have exactly the same name in .qml file as in .h file
}
}