QT4 HTTP Example and Redirecting

[jiveaxe]

Hi,
I was trying the HTTP Example of qt4 documentation and noticed that it can't manage itself the status code 302, it can't perform a redirection.

An example is this link:
http://next.videogame.it/img/articoli/4500/4905/projectsnowblind_recensione.cover.T5.jpg

With the line below I get the new url:


QString newLocation = responseHeader.value("Location");

But I don't know how to use it.

Have anybody some tips for me?

Thanks

EDITED: HTTP Example (http://doc.trolltech.com/4.4/network-http.html)

[wysota]

When you receive the new location simply change the url of the request to the one you received in the location header and resubmit the request.

[profoX]

I had the same problem sometime ago.
I solved it like this:


self.connect(self.http, SIGNAL("responseHeaderReceived(const QHttpResponseHeader &)"), self.handleHeaderResponse)

[...]

def handleHeaderResponse(self, resp):
code = resp.statusCode()
if (code >= 300 and code < 400 and resp.hasKey("location")):
location = QUrl(resp.value("location"))
self.http.setHost(location.host())
self.http.get(location.toString())

As you can see it's copied from my PyQt4 application... In C++ it should be something like this (not tested!)


connect(http, SIGNAL(responseHeaderReceived(const QHttpResponseHeader &)), this, SLOT(handleHeaderResponse(const QHttpResponseHeader &)));

[...]

void MyClass::handleHeaderResponse(const QHttpResponseHeader &resp):
int code = resp.statusCode();
if (code >= 300 and code < 400 and resp.hasKey("location")) {
QUrl location = QUrl(resp.value("location"));
http.setHost(location.host());
http.get(location.toString());
}

Hope it helps you!

[jiveaxe]

I'm trying different ways but with no luck.

First of all the code:


class InternetJob: public QObject
{
Q_OBJECT

public:
InternetJob(const QString &u);
QByteArray getData(){return data;}
int getStatusCode(){return statusCode;}
QString getLocation(){return location;}
bool isRequestAborted(){return httpRequestAborted;}
bool isRedirecting(){return needRedirect;}
void download();

private slots:
void httpRequestFinished(int requestId, bool error);
void readResponseHeader(const QHttpResponseHeader &responseHeader);

signals:
void requestFinished();

private:
QHttp *http;
QUrl url;
bool httpRequestAborted;
int httpGetId;
QByteArray data;
int statusCode;
QString location;
};

InternetJob::InternetJob(const QString &u)
: url(u)
{
http = new QHttp;
connect(http, SIGNAL(responseHeaderReceived(const QHttpResponseHeader &)), this, SLOT(readResponseHeader(const QHttpResponseHeader &)));
connect(http, SIGNAL(requestFinished(int, bool)), this, SLOT(httpRequestFinished(int, bool)));

download();
}

void InternetJob::download()
{
QString query;
for(int i = 0; i < url.queryItems().size(); ) {
query += url.queryItems().at(i).first + "=" + url.queryItems().at(i).second;
if(++i < url.queryItems().size())
query += "&";
}

QHttpRequestHeader header;
if(url.queryItems().size() > 0)
header.setRequest("GET", url.path() + "?" + QUrl::toPercentEncoding(query,"&="));
else
header.setRequest("GET", url.path());
header.setValue("Host", url.host());

httpRequestAborted = false;
http->setHost(url.host());
httpGetId = http->request(header);
qDebug() << "job id = " << httpGetId;
}

void InternetJob::readResponseHeader(const QHttpResponseHeader &responseHeader)
{
statusCode = responseHeader.statusCode();
QRegExp rx("\?$");

switch(statusCode) {
case 200:
case 301:
case 303:
case 307:
break;

case 302:
location = responseHeader.value("Location");
// Remove trailing "?"
location.remove(rx.indexIn(location), 1);
httpRequestAborted = true;
http->abort();
break;

default:
qDebug() << QString(trUtf8("Download failed: %1.").arg(responseHeader.reasonPhrase()));
httpRequestAborted = true;
http->abort();
}
}

void InternetJob::httpRequestFinished(int requestId, bool error)
{
if (requestId != httpGetId)
return;
qDebug() << "job finished = " << requestId;
if (httpRequestAborted) {
qDebug() << "Request Aborted. Status Code: " << statusCode;
if(statusCode == 302) {
url.setUrl(location);
download();
return;
}
else {
emit requestFinished();
return;
}
}

if(error)
qDebug() << QString(trUtf8("Download failed: %1.").arg(http->errorString()));
else
data = http->readAll();
emit requestFinished();
}

The code above works well until the http status code is 200; if the status code is 302 it starts a new http->request(...) but after it neither responseHeaderReceived nor httpRequestFinished signals are emitted.

Where is my mistake?

Thanks