HTTP request

[Trok]

I have tried to make http request with GET method, but I couldn't obtain the result of it.
My code:

QHttp http;
    http.setHost("appmsg.gadu-gadu.pl");
    QHttpRequestHeader dataRequest("GET", QUrl::toPercentEncoding("/appsvc/appmsg4.asp?fmnumber=1247818&version=7,0,0,20&lastmsg=1"));
    dataRequest.setValue("Accept-Language", "pl");
    dataRequest.setValue("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows 98)");
    dataRequest.setValue("Pragma", "no-cache");
    dataRequest.setValue("Host", "appmsg.gadu-gadu.pl");
    http.request(dataRequest);
    QString dataResult = http.readAll();
    qDebug() << dataResult;

QHttp http;
    http.setHost("appmsg.gadu-gadu.pl");
    QHttpRequestHeader dataRequest("GET", QUrl::toPercentEncoding("/appsvc/appmsg4.asp?fmnumber=1247818&version=7,0,0,20&lastmsg=1"));
    dataRequest.setValue("Accept-Language", "pl");
    dataRequest.setValue("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows 98)");
    dataRequest.setValue("Pragma", "no-cache");
    dataRequest.setValue("Host", "appmsg.gadu-gadu.pl");
    http.request(dataRequest);
    QString dataResult = http.readAll();
    qDebug() << dataResult;

To copy to clipboard, switch view to plain text mode 

What's wrong in this code? Why can't I get the result of request?

[wysota]

QHttp works in an asynchronous manner. You have to wait until the request result is ready.

[squidge]

Yes, if http.request worked in the way you have used it, you main program would hang until the result was received or an error occured, which is definitely not what you want.

Use signals and slots.

[Trok]

This is my improve code:

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent), ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    http = new QHttp("appmsg.gadu-gadu.pl");
    QHttpRequestHeader dataRequest("GET", QUrl::toPercentEncoding("/appsvc/appmsg4.asp?fmnumber=1247818&version=7,0,0,20&lastmsg=1"));
    dataRequest.setValue("Accept-Language", "pl");
    dataRequest.setValue("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows 98)");
    dataRequest.setValue("Pragma", "no-cache");
    dataRequest.setValue("Host", "appmsg.gadu-gadu.pl");
    http->request(dataRequest);
    QObject::connect(http, SIGNAL(requestFinished(int, bool)), this, SLOT(function(int, bool)));
}

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent), ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    http = new QHttp("appmsg.gadu-gadu.pl");
    QHttpRequestHeader dataRequest("GET", QUrl::toPercentEncoding("/appsvc/appmsg4.asp?fmnumber=1247818&version=7,0,0,20&lastmsg=1"));
    dataRequest.setValue("Accept-Language", "pl");
    dataRequest.setValue("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows 98)");
    dataRequest.setValue("Pragma", "no-cache");
    dataRequest.setValue("Host", "appmsg.gadu-gadu.pl");
    http->request(dataRequest);
    QObject::connect(http, SIGNAL(requestFinished(int, bool)), this, SLOT(function(int, bool)));
}

To copy to clipboard, switch view to plain text mode 

void MainWindow::function(int id, bool error){
    qDebug() << "Test";
 
    if(error){
        qDebug() << http->errorString();
        return;
    }
 
    QString dataResult = http->readAll();
    qDebug() << dataResult;
}

void MainWindow::function(int id, bool error){
    qDebug() << "Test";

    if(error){
        qDebug() << http->errorString();
        return;
    }

    QString dataResult = http->readAll();
    qDebug() << dataResult;
}

To copy to clipboard, switch view to plain text mode 

Output return:

Starting C:/Documents and Settings/Trok/Pulpit/Qt Progs/Test_gg/debug/Test_gg.exe...
NOD32 protected [MSAFD Tcpip [TCP/IP]]NOD32 protected [MSAFD Tcpip [UDP/IP]]NOD32 protected [MSAFD Tcpip [RAW/IP]]NOD32 protected [RSVP UDP Service Provider]NOD32 protected [RSVP TCP Service Provider]Test 
""

Starting C:/Documents and Settings/Trok/Pulpit/Qt Progs/Test_gg/debug/Test_gg.exe...
NOD32 protected [MSAFD Tcpip [TCP/IP]]NOD32 protected [MSAFD Tcpip [UDP/IP]]NOD32 protected [MSAFD Tcpip [RAW/IP]]NOD32 protected [RSVP UDP Service Provider]NOD32 protected [RSVP TCP Service Provider]Test 
""

To copy to clipboard, switch view to plain text mode 

What's wrong else?

[squidge]

Really, connect should go before the request, but it seems like your firewall (NOD32?) might be interfering with your application

[wysota]

Connect can go after the request. Qt assures the signal will not be delivered until the application re-enters the event loop. Anyway it seems the firewall is blocking the connection as suggested.

[squidge]

Is that a general rule, wysota? I was thinking if maybe a signal was emitted in the request method (not the complete, but maybe an error signal) that Qt wouldn't actually emit or queue the signal as there was no listeners at the time it was emitted.

[Trok]

I closed NOD32 and all the firewalls but I have still the same communique:

Starting C:/Documents and Settings/Trok/Pulpit/Qt Progs/Test_gg/debug/Test_gg.exe...
NOD32 protected [MSAFD Tcpip [TCP/IP]]NOD32 protected [MSAFD Tcpip [UDP/IP]]NOD32 protected [MSAFD Tcpip [RAW/IP]]NOD32 protected [RSVP UDP Service Provider]NOD32 protected [RSVP TCP Service Provider]Test
""

I suppose that the firewall don't block this operation, because I can send POST request by SOCKET correctly.

[wysota]

Is that a general rule, wysota?

With networking classes - yes.

I was thinking if maybe a signal was emitted in the request method (not the complete, but maybe an error signal) that Qt wouldn't actually emit or queue the signal as there was no listeners at the time it was emitted.

All "request" type of methods don't do anything. They just schedule execution.

[mgoetz]

Small side note: Use QNetworkAccessManager. QHttp is deprecated.