QT DOMXml - Change the name of a node

Question

I am working on a QT Project and part of that is a reconstruction of an XML file. I was able to make most of the needed changes with QDom but I can't find how to rename a node.
So the old XML file looks like ..

<root>
<window name="" ..>
<element x="" y=""/>
<element1 a="" b=""/>
...
</window>
..
..
<window name="">
<element x="" y=""/>
<element1 a="" b=""/>
...
</window>
</root>

How can i change the XML so that the new one will have < group > instead of < window >?

So at the end it needs to look like..

<root>
    <group name="" ..>
    <element x="" y=""/>
    <element1 a="" b=""/>
    ...
    </group>
    ..
    ..
    <group name="">
    <element x="" y=""/>
    <element1 a="" b=""/>
    ...
    </group>
    </root>

Adding some more info...
Here is the code I use to read the <window> nodes, delete some based on the visibility (comes from a list) and I need to change <window> to <group> for the remaining nodes.

QFile oldXml("file.xml");
    oldXml.open(QIODevice::ReadOnly);
    QDomDocument doc;
    doc.setContent(&oldXml);
    QDomNodeList nodes = doc.elementsByTagName("window");
    // Remove Window nodes based  on visibility
    insize = nodes.length();
    for ( int i = 0; i < insize; i++ ) {

       QDomNode node = nodes.at(i-dels);
       if ( (list2[i] == "0") | (list2[i]=="") )  {
           node.parentNode().removeChild(node);
            dels=dels+1;
       } else {
           // Here is where i need to change the node name from <window> to e.g. <group>
       }
     }

@EdChum, he is asking for editing the "name" not the "Value". — Pavan Chandaka, Oct 23 '16 at 23:40

score 0 · Answer 1 · answered Oct 23 '16 at 22:06

I did not see any straight API function to rename the element. API is allowing to change value but not name.

There is another round about way.

Create an element, for example:

QDomElement group = doc.createElement("group");

use "QDomNode's replacechild" function.

QDomNode QDomNode::replaceChild(const QDomNode &newChild, const QDomNode &oldChild)

ex:

QDomNode dNode = node.replaceChild(group,oldNode);

Tarod · Accepted Answer · 2016-10-23T22:27:06.820

You could use setTagName and maybe setAttribute if you want to set a value for the name attribute.

With the following example, myxml.xml is converted to xmlout.xml

Note#1: this is just an example: we're replacing only the first node.
Note#2: in this example, we're using two different files. Depending on your design, you could use the same or not.

myxml.xml

<root>
<window name="">
<element x="" y=""/>
<element1 a="" b=""/>
</window>
<window name="">
<element x="" y=""/>
<element1 a="" b=""/>
</window>
</root>

xmlout.xml

<root>
    <group name="value">
        <element y="" x=""/>
        <element1 a="" b=""/>
    </group>
    <window name="">
        <element y="" x=""/>
        <element1 a="" b=""/>
    </window>
</root>

main.cpp

#include <iostream>
#include <QtXml>
#include <QFile>

int main(int argc, char *argv[])
{
    QDomDocument doc;
    // Load xml file as raw data
    QFile inFile(":myxml.xml");
    if (!inFile.open(QIODevice::ReadOnly ))
    {
        std::cerr << "Error - inFile: " << inFile.errorString().toStdString();
        return 1;
    }
    // Set data into the QDomDocument before processing
    doc.setContent(&inFile);

    // Get element in question
    QDomElement root = doc.documentElement();
    QDomElement nodeTag = root.firstChildElement("window");

    nodeTag.setTagName("group");
    nodeTag.setAttribute("name","value");

    inFile.close();

    // Save the modified data
    QFile outFile("xmlout.xml");
    if (!outFile.open(QIODevice::WriteOnly ))
    {
        // Error while loading file
        std::cerr << "Error - outFile: " << outFile.errorString().toStdString();
        return 1;
    }

    QTextStream stream;
    stream.setDevice(&outFile);
    stream.setCodec("UTF-8");
    doc.save(stream,4);
    outFile.close();

    return 0;
}

That did the job. Maybe i need to polish my XML knowledge a bit. The answer was right in front of me. Thanks for the heads up. — BobR, Oct 24 '16 at 05:48

QT DOMXml - Change the name of a node

2 Answers2