QDomDocument and reading XML

[prashant]

Hi,

First time using QT and XML. Here is my simple XML file.

<?xml version="1.0"?>
 
<Node   nodetype="atomic"
            header="atomic.h">
 
<Input name="inNumber" type="color" value="0.2,0.3,0.5"/>
<Output name="outNumber" type="float" value="0.5"/>  
 
</Node>

<?xml version="1.0"?>

<Node   nodetype="atomic"
            header="atomic.h">
                      
<Input name="inNumber" type="color" value="0.2,0.3,0.5"/>
<Output name="outNumber" type="float" value="0.5"/>  

</Node>

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and here is the QT code:

QFile file("atomic.xml");
    if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
        return 0;
 
    QDomDocument doc;
    if (!doc.setContent(&file)) {
        file.close();
        return 0;
    }
    file.close();
 
    QDomNode n = doc.firstChild();
 
    while(!n.isNull()) {
 
            if(n.isElement()) {
 
                QDomElement e = n.toElement();
                QString name = e.tagName();
 
                qDebug() << name;
 
                if(name == "Node") {
 
                    QString nodeType = e.attribute("nodetype","");
                    QString header = e.attribute("header","");
                    qDebug() << nodeType << header;
 
                } else if(name == "Input") {
 
                    QString name1 = e.attribute("name","");
                    QString type1 = e.attribute("type","");
                    QString value1 = e.attribute("value","");
 
                    qDebug() << name1 << type1 << value1;
                }
            }
            n = n.nextSibling();
        }

QFile file("atomic.xml");
    if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
        return 0;

    QDomDocument doc;
    if (!doc.setContent(&file)) {
        file.close();
        return 0;
    }
    file.close();

    QDomNode n = doc.firstChild();
    
    while(!n.isNull()) {

            if(n.isElement()) {

                QDomElement e = n.toElement();
                QString name = e.tagName();

                qDebug() << name;

                if(name == "Node") {

                    QString nodeType = e.attribute("nodetype","");
                    QString header = e.attribute("header","");
                    qDebug() << nodeType << header;

                } else if(name == "Input") {

                    QString name1 = e.attribute("name","");
                    QString type1 = e.attribute("type","");
                    QString value1 = e.attribute("value","");

                    qDebug() << name1 << type1 << value1;
                }
            }
            n = n.nextSibling();
        }

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Problem 1
The code is not entering in condition:

else if(name == "Input") {

else if(name == "Input") {

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Cheers

Prashant

[estanisgeyer]

Hi,

The tag "Input" is child the node "Node". Is its problem.

Marcelo E. Geyer

[prashant]

Not able to get the child nodes of "Node" this way:

for(signed i(0); i<n.childNodes().count();i++){
 
        QDomNode childNode = n.childNodes().item(i);
        QDomElement e = childNode.toElement();
        QString name = e.tagName();
        if(name == "Input") {
 
            QString name1 = e.attribute("name","");
            QString type1 = e.attribute("type","");
            QString value1 = e.attribute("value","");
 
            qDebug() << name1 << type1 << value1;
        }

for(signed i(0); i<n.childNodes().count();i++){
           
        QDomNode childNode = n.childNodes().item(i);
        QDomElement e = childNode.toElement();
        QString name = e.tagName();
        if(name == "Input") {

            QString name1 = e.attribute("name","");
            QString type1 = e.attribute("type","");
            QString value1 = e.attribute("value","");

            qDebug() << name1 << type1 << value1;
        }

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It's because:

n.hasChildNodes(); // = 0

n.hasChildNodes(); // = 0

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[prashant]

I didn't find any solution so far. May be some one point out the solution.

Cheers

Prashant

[faldzip]

chage this:

QDomNode n = doc.firstChild();

QDomNode n = doc.firstChild();

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to this:

QDomElement e = doc.documentElement(); // now e contains "Node" - it's a document element - means root element

QDomElement e = doc.documentElement(); // now e contains "Node" - it's a document element - means root element

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and use QDomElements if you want to get only elements. You can iterate through "Node" childs like this:

QDomElement child = e.firstChildElement();
while (!child.isNull()) {
    // do sth with child
    // it should be "Input" in first iteration and "Output" in second one
    child = child.nextSiblingElement();  // move 'child' to be the next sibling element
}

QDomElement child = e.firstChildElement();
while (!child.isNull()) {
    // do sth with child
    // it should be "Input" in first iteration and "Output" in second one
    child = child.nextSiblingElement();  // move 'child' to be the next sibling element
}

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