Access a variable from another class - c++

Question

I have two classes, MyClass and Widget. Below is the MyClass class and from my Widget class i want to get the str variable. How is that done?
class MyClass : public QObject
{
Q_OBJECT
public:
MyClass();
void fetch();
public slots:
void replyFinished(QNetworkReply*);
private:
QNetworkAccessManager* m_manager;
};
MyClass::MyClass()
{
m_manager = new QNetworkAccessManager(this);
connect( m_manager, SIGNAL(finished(QNetworkReply*)),
this, SLOT(replyFinished(QNetworkReply*)));
}
void MyClass::fetch()
{
m_manager->get(QNetworkRequest(QUrl("http://stackoverflow.com")));
}
void MyClass::replyFinished(QNetworkReply* pReply)
{
QByteArray data=pReply->readAll();
QString str(data);
//this str should be available in my widget class
}
EDIT: Here is a the important part of the widget
namespace Ui {
class Widget;
}
class Widget : public QWidget
{
Q_OBJECT
public:
explicit Widget(QWidget *parent = 0);
~Widget();
private slots:
void on_pushButton_clicked();
private:
Ui::Widget *ui;
};
Widget::Widget(QWidget *parent) :
QWidget(parent),
ui(new Ui::Widget)
{
ui->setupUi(this);
}
Widget::~Widget()
{
delete ui;
}
void Widget::on_pushButton_clicked()
{
//here str should be accessed
}

Answer 1

If you want the str variable from your function available to classes or other functions, here are two choices:
Return it from the function.
Declare a variable in MyClass to hold the string and set the
variable to the value.
Case 1: Returning from a function
QString MyClass::replyFinished(...)
{
QString str(data);
return data;
}
Case 2: Declare a class member variable
class MyClass
{
public:
QString m_replyStr;
};
//...
void MyClass::replyFinished(...)
{
QByteArray data = pReply->readAll();
m_replyStr = data;
}
Modifying your question with an example of what you want to do would be very helpful.

Answer 2

You can emit a signal with str as argument and connect it to a slot in your widget. Then you can do what you want with it.
This way you will preserve the event oriented design and you have not need to control if str exists. Simply when it's ready the slot will handle it.
class MyClass : public QObject
{
Q_OBJECT
public:
MyClass();
void fetch();
public slots:
void replyFinished(QNetworkReply*);
signals:
void strReplyReady(QString str);
private:
QNetworkAccessManager* m_manager;
};
...
void MyClass::replyFinished(QNetworkReply* pReply)
{
QByteArray data=pReply->readAll();
QString str(data);
emit strReplyRead(str);
}
your Widget
class MyWidget : public QWidget
{
//public members
...
public slots:
void readReply(QString str);
}
void MyWidget::readReply(QString str){
//do what you want with str
}
in the main.cpp you do the connect with the static member of QObject
QObject::connect(myClassPointer,SIGNAL(strReplyReay(QString)) ,
myWidgetPointer,SLOT(readReply(QString)));