How to update child-data in XML file?

nishiokas

Hi.

I'd like to change "commonPrimaryUri" value in this XML file.
As follow.

<?xml version="1.0" encoding="UTF-8"?>
<tResource version="1.3.0">
    <common>
        <commonPrimaryUri>http://192.168.39.91:8000/common-shop/</commonPrimaryUri>
    </common>
</thincaResource>

I wrote this code.
It can works, but this result is different from what I expected.

QDomDocument xmlBOM;
QFile f("/home/root/d/resource/resource.xml");
if (f.open(QIODevice::ReadOnly))
{
    xmlBOM.setContent(&f);
    f.close();

    QDomNodeList domList = xmlBOM.elementsByTagName("common");
    QDomElement element = domList.at(0).toElement();
    element.setAttribute("commonPrimaryUri", url);
    if (f.open(QIODevice::Truncate | QIODevice::WriteOnly))
    {
        QByteArray xml = xmlBOM.toByteArray();
        f.write(xml);
        f.close();
    }
}

this is result.

<?xml version='1.0' encoding='UTF-8'?>
<thincaResource version="1.3.0">
    <common commonPrimaryUri="http://1.2.3.4:8000/common-shop/">
        <commonPrimaryUri>http://192.168.39.91:8000/common-shop/</commonPrimaryUri>
        ...

I don't want to change <common> data.
I'd like to change <commonPrimaryUri> data.
like this

<common>
    <commonPrimaryUri>http://1.2.3.4:8000/common-shop/</commonPrimaryUri>
</common>

Which part should I change?
Thanks.

JonB

@nishiokas said in How to update child-data in XML file?:

element.setAttribute("commonPrimaryUri", url);

This sets an attribute on (the first) xmlBOM.elementsByTagName("common");, resulting in <common commonPrimaryUri="http://1.2.3.4:8000/common-shop/">.

You say you don't want that. You want to operate on the <commonPrimaryUri> child element of <common>. So do that. (Visit <common> children, or element.elementsByTagName("commonPrimaryUri").)

nishiokas

@JonB Thank you for your reply!

(Visit <common> children, or element.elementsByTagName("commonPrimaryUri").)

I used "element.elementsByTagName("commonPrimaryUri")" instead of "xmlBOM.elementsByTagName("common")".
But I couldn't get positive result.

QDomNodeList domList = xmlBOM.elementsByTagName("commonPrimaryUri");
QDomElement element = domList.at(0).toElement();
element.setAttribute("", "http://1.2.3.4:8000/common-shop/");    
// result  XML
// <commonPrimaryUri ="http://1.2.3.4:8000/common-shop/">http://192.168.39.91:8000/common-shop/</commonPrimaryUri>
element.setNodeValue("http://1.2.3.4:8000/common-shop/");
//retult XML
//nothing change
element.setTagName("http://1.2.3.4:8000/common-shop/");
//retult XML
//  <http://1.2.3.4:8000/pos-api/close>http://192.168.39.91:8000/pos-api/close</http://1.2.3.4:8000/pos-api/close>

I'm afraid I don't understand how to visit "<common> children".
Should I use "appendChld" in QDomNodeList?

How should I call this potision? "<tag>here!</tag>"
I think it's "Value" but setNodeValue couldn't change anything.

thanks.

JonB

@nishiokas
Please don't introduce setAttribute() or setTagName(), they are not what you want and just unnecessarily complicate the code.

element.setNodeValue("http://1.2.3.4:8000/common-shop/");

If I am not mistaken, <commonPrimaryUri> does not directly have the value. Rather, it has a child node, of type QDomText, which has the text you want to alter. Try enumerating <commonPrimaryUri>'s children to see if I am right.