qxmlstreamreader how to skip /end

zicx

I have a simple xml

<?xml version="1.0"?>
<config_file>

<config symbol="A">
	<val_1>3200</val_1>
	<val_2>2000</val_2>
	<val_3>1000</val_3>
</config>

</config_file>

and a reader

void XmlReader::Read() {

    QFile xml_file(this->filename_);
    xml_file.open( QIODevice::ReadOnly );
    this->xml_.setDevice( &xml_file );

    if ( xml_.readNextStartElement() && xml_.name() == "config_file") {

        while ( !xml_.atEnd() ) {

            std::string field = xml_.name().toString().toStdString();
            xml_.readNext();

            std::string value = xml_.text().toString().toStdString();

            std::cout << " Next " << field << " " << value << std::endl;


            xml_.readNextStartElement();

        }
    }
}

The loop prints

File Found
Next config_file

Next config

Next val_1 3200
Next val_1

Next val_2 2000
Next val_2

Next val_3 1000
Next val_3

Next config

Next config_file

So, it seem readNextStartElement() goes to the closing elements as well ( the </...> )

Is there a way to avoid that? Or is there something else I am doing wrong?

Paul Colby

Hi @zicx,

So, it seem readNextStartElement() goes to the closing elements as well ( the </...> )

Correct. As per the docs for QXmlStreamReader::readNextStartElement:

Reads until the next start element within the current element.

(emphasis mine). And also:

The current element is the element matching the most recently parsed start element of which a matching end element has not yet been reached.

Is there a way to avoid that?

Depending on what you want, either check the result of readNextStartElement (returns a boolean). Or, use QXmlStreamReader::skipCurrentElement end of each loop, before calling readNextStartElement.

Cheers.

VRonin

while (!xml_.atEnd() && !xml_.hasError()) {
            xml_.readNext();
if (xml_.isStartElement()) {
if (xml_.name() == QStringLiteral("val_1")) {
std::cout << "Val1 " << qPrintable(xml_.readElementText())
}
if (xml_.name() == QStringLiteral("val_2")) {
std::cout << "Val2 " << qPrintable(xml_.readElementText())
}
if (xml_.name() == QStringLiteral("val_3")) {
std::cout << "Val3 " << qPrintable(xml_.readElementText())
}
}

zicx

@Paul

"Reads until the next start element within the current element"

Oh, I misunderstood. I expected it to jump to the next startelement... so it first reads, then I move next, then it reads again and the output was blank because there was no next in that element anymore?

@VRonin
The readElementext is quite neat, I like that thanks

One more question out of curiosity. How do I read out

 <config symbol="A">

the symbol code. I trued with readElementText, but that does not work

VRonin

if (xml_.name() == QStringLiteral("config ")) {
std::cout << "Val1 " << qPrintable(xml_.attributes().value(QStringLiteral("symbol")))
}

zicx

@VRonin

thanks