Login to website using Qt - c++

Question

I need to login to a website to retrieve the source code of a page. How would I do this using Qt?
I'm not familiar with how QUrl and QNetworkAcessManager work, but I was able to write code that would allow me to download the source code for any page not behind a login form.
This is what I have so far. I end up just downloading the source for the redirect page:
test = new QNetworkAccessManager(this);
QUrl URL = QUrl("http://website.com/page");
URL.setUserName("user");
URL.setPassword("password");
test->get(QNetworkRequest(URL));
Edit:
QByteArray loginData("username=user&password=password");
QNetworkRequest request(QUrl("http://website.com/login/index.php"));
manager->post(request,loginData);
QUrl URL = QUrl("http://website.com/mod/resource/view.php?id=114198");
manager->get(QNetworkRequest(URL));
I am still retrieving a 303 reply.
The page is on Moodle, which uses a HTTP POST login form.
I've also tried with a different site. POST works but I get the source code of the login page with the login form filled out. Not sure how to get the page after logging in.

Answer 1

This was my solution, for logging into a particular website and retrieving a file. I was getting redirected multiple times before reaching the destination. I test HTTP status codes until I get the final reply. I also test to see if the final URL is the one I requested and not some home page behind the login page. This is because I am downloading a file.
QByteArray loginData;
loginData.append("username="+(ui->lineEdit_2->text())+"&password="+(ui->lineEdit_3->text())+"&action=login");
cookiesHandler* test = new cookiesHandler(this);
QUrl request("http://website.com");
test->sendPostRequest(request, loginData);
Cookies Handler Class
class cookiesHandler: public QObject{
Q_OBJECT
public:
cookiesHandler(QObject *parent = 0) : QObject(parent){
mManager = new QNetworkAccessManager(this);
mManager->setCookieJar(new QNetworkCookieJar(this));
connect(mManager, SIGNAL(finished(QNetworkReply*)), SLOT(replyFinished(QNetworkReply*)));
}
void sendPostRequest(const QUrl &url, const QByteArray &data){
mUrl = url;
login = data;
QNetworkRequest r(mUrl);
mManager->post(r, data);
}
void sendGetRequest(const QUrl &url)
{
mUrl = url;
test = mUrl;
QNetworkRequest r(mUrl);
mManager->get(r);
}
virtual ~cookiesHandler(){}
private slots:
void replyFinished(QNetworkReply *reply){
if (reply->error() != QNetworkReply::NoError){
qWarning() << "ERROR:" << reply->errorString();
return;
}
//Cookies//
QList<QNetworkCookie> cookies = mManager->cookieJar()->cookiesForUrl(mUrl);
qDebug() << "COOKIES for" << mUrl.host() << cookies;
QString str;
QDebug dStream(&str);
dStream << mUrl.host() << cookies;
//End Cookies//
int v = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();
if (v >= 200 && v < 300) // Success
{
getFile(reply);
// Here we got the final reply
return;
}
else if (v >= 300 && v < 400) // Redirection
{
/* Use Cookies for Login */
qDebug() << "REDIRECTING";
rUrl = reply->attribute(QNetworkRequest::RedirectionTargetAttribute).toUrl();
if(rUrl != mUrl)
{
mManager->post(QNetworkRequest(rUrl),login);
return;}
out << QString("redirected: " + rUrl.toEncoded()) << endl;
QNetworkRequest r(mUrl);
QVariant var;
var.setValue(cookies);
r.setHeader(QNetworkRequest::CookieHeader, var);
mManager->get(r);
return;
}
}