QNetworkReply Just download the head of the Url file

An other french

Hello,
See below a part of the code which i want to make advanced

void Form::testNum (QString num)
{
    qDebug() << num;

    manager = new QNetworkAccessManager(this);

    QNetworkRequest request;
    request.setUrl(QUrl("http://www.xxxxxx.com/"+num));

    response = manager->get(request);

    connect(response, &QNetworkReply::finished,this,&Form::getResult );
}

void Form::getResult() {
    qDebug() << "Finished";
    qDebug() << response->readAll();
    response->deleteLater();
    response = Q_NULLPTR;
}

I saw the way to store it in a QByteArray to make an analysis.
But do you think is possible to get a part of the html code like the <head> without downloading all the file?

Thanks for reading.
Bye.

An other french

void Form::getResult() {
    qDebug() << "Finished";
    //qDebug() << response->readAll();
    QByteArray output = response->readAll();
    QString tmp = output;
    QStringList list;
    list = tmp.split(QRegExp("<head>"));
    tmp=list[1];
    list=tmp.split("</head>");
    tmp=list[0];
    qDebug() << "Head is : " + tmp;

    response->deleteLater();
    response = Q_NULLPTR;
}

Easy to write but it's not my point of view.

raven-worx

@An-other-french said in QNetworkReply Just download the head of the Url file:

But do you think is possible to get a part of the html code like the <head> without downloading all the file?

your example still downloads the whole file.

Just downloading selectively a part of a HTML content isn't possible.
Instead of connecting to the QNetworkReply::finished signal you can connect to the readyRead signal and save the response's data in a buffer until you find </head>.

void Form::getResult() {
    m_Buffer += response->readAll();
    
   int found = m_Buffer.indexOf("</head>");
    if( found >= 0 )
   {
         response->deleteLater(); // implicitly aborts the request if not yet finished
         response = Q_NULLPTR;
   }
}

But also note, that not each HTML page is required to have a <head> tag.

An other french

Thanks.
Changing the signal is smart.

In another way, i look for a protocol like "robot" which just catching the summary of the internet page.
It'll be construct with the metadatas built with the <head> of the page ( get_meta_tags in php ).

Perhaps this.

raven-worx

@An-other-french said in QNetworkReply Just download the head of the Url file:

Perhaps this.

but those are HTTP headers and have nothing todo with HTML headers.
If you are just interested in the HTTP-Headers then use QNetworkAccessManager::head() (instead of get()) and the content-body is not transferred.

HTML-headers are contained in the data-body und thus need to be requested via get() - and be read with the approach i've posted.