Can't stop EventLoop by signal in class

Subuday

I emit signal but EventLoop still continue work.

class Client : public QObject
{
    Q_OBJECT
public:
    explicit Client(QObject *parent = nullptr);

    int result;

    void getFinish();
    int getResult();

signals:
    void finishStatus();
};

int Client::getResult()
{
    QEventLoop loop;
    connect(this, SIGNAL(finishStatus()), &loop, SLOT(quit()));
    getFinish();
    loop.exec();
    return result;
}

void Client::getFinish() {
     result = 2 + 3;
    emit finishStatus();
}

Also I try call getFinish() above EventLoop:

int Client::getResult()
{
    getFinish();
    QEventLoop loop;
    connect(this, SIGNAL(finishStatus()), &loop, SLOT(quit()));
    loop.exec();
    return result;
}

mrjj

Hi
the emit is like a direct function call so it has happened when code
reaches loop.exec();
Use
connect(this, SIGNAL(finishStatus()), &loop, SLOT(quit()), Qt::QueuedConnection);
and it should work.

J.Hilk

@Subuday
@mrjj is right of course,

But I have the feelings, from what you showed so far, that you'll end up in trouble later down the road.

Can you tell us, what exactly you want to archive ?

Subuday

@J.Hilk I need wait for data from Http Request but the solution doesn't help.
My code:

void Client::getProjTypesRequest(const int &id)
{
    QString uri = "projectTypeList?option=%1";
    QNetworkRequest request(url + uri.arg(id));
    QNetworkReply *reply = manager->get(request);
    connect( reply, SIGNAL(finished()),this, SLOT(authenticationReply()));
}

void Client::getProjTypesReply()
{
    QNetworkReply *reply = qobject_cast<QNetworkReply *>(sender());
    qDebug() << "getProjTypesReply";

    if (reply->error() == QNetworkReply::NoError)
    {
      qDebug() << "getProjTypesReply: OK!";
      QByteArray httpReply = reply->readAll();
      qDebug() << httpReply;

      QJsonDocument jsonResponse = QJsonDocument::fromJson(httpReply);
      QJsonArray jsonArray = jsonResponse.array();
      foreach(const QJsonValue & value, jsonArray)
      {
          QJsonObject obj = value.toObject();
          QMap<QString, QString> projectType;
          projectType.insert("id", obj["id"].toString());
          projectType.insert("name", obj["name"].toString());
          projectTypeList.append(projectType);
      }

      emit getProjectTypesStatus();
      manager->clearAccessCache();
    }
    else
    {
        qDebug() << reply->errorString();
        emit getProjectTypesStatus();
        manager->clearAccessCache();
    }
    reply->deleteLater();
}

QList<QMap<QString, QString> > Client::getProjectTypeList(const int &projectField)
{
    QEventLoop loop;
    getProjTypesRequest(projectField);
    connect(this, SIGNAL(getProjectTypesStatus()), &loop, SLOT(quit()), Qt::QueuedConnection);
    loop.exec();
    qDebug() << "projectTypeList Length:";
    qDebug() << projectTypeList.length();
    return projectTypeList;
}
``

mrjj

Hi
Try flip the lines (connect first)
getProjTypesRequest(projectField);
connect(this, SIGNAL(getProjectTypesStatus()), &loop, SLOT(quit()), Qt::QueuedConnection);

Anyway, why do you need to wait?
If you just use the normal async API, you are called when data is read and
when ready, you can process data and emit a signal to tell other objects that task is done.

Subuday

@mrjj I get data from my server for the list Model.

EDIT
flips line doesn't help!
I gets qDebug() << "projectTypeList Length:" ; only when I close programm.

void TypeProjectListModel::load(const int &projectField)
{
    listData = client->getProjectTypeList(projectField);
}

mrjj

@Subuday
Well your small sample works so that must mean you are doing something slightly different.