How to modify value in existing XML element?

AaronKelsey

I have iterated over my XML document and I have been able to check whether the element exists. Unfortunately I am struggling to find the correct functions in the Qt documentation to then change the value of the element.

This is the XML document I am loading and reading. I would like to change the string value of ItemB.

<root>
    <item argtype="single" name="ItemA">
        <value type="uint32">123</value>
    </item>
		
     <item argtype="single" name="ItemB">
        <value type="string">ChangeThisValueHere</value>
    </item>
</root>

I have accessed the node iterating over the XML document using this method.

QDomElement qRoot = mqConfig.documentElement();

  if (!qRoot.isNull())
  {
    QDomNodeList qDomNodeList = qRoot.elementsByTagName("item");

    bool bItemB= false;

    for (int i = 0; i < qDomNodeList.size(); i++)
    {
      QDomElement domElement = qDomNodeList.at(i).toElement();

      if (domElement.attribute("name") == "ItemB")
      {
        // Modify Value "ChangeThisValueHere" 

        bCertExists = true;
      }
      else
      {
        bCertExists = false;
      }
    }

    if (!bCertExists)
    {
      createItem(qRoot, "SSL Certificate", "string", sCertFileName);
    }
  }

Any help would be greatly appreciated

mrjj

Hi
You can just use
https://doc.qt.io/qt-5/qdomelement.html#setAttribute
to change a attributes value.
Please notice that you need to save it back to file for the changes to be permanent.

Update: Just noticed the "ChangeThisValueHere" which is not an attribute but node text / text node.

AaronKelsey

@mrjj so I'd simply write domElement.setAttribute("ItemB", ""newValueHere"); ?

JonB

@AaronKelsey
No. And anyway I'm not sure that's right for what you are asking....

I would like to change the string value of ItemB.

     <item argtype="single" name="ItemB">
        <value type="string">ChangeThisValueHere</value>
    </item>

So you want to alter ChangeThisValueHere? That is not an attribute. That is the (text) value of the <value> element.

I can see @mrjj has taken your goal as to change the <value type="string"> to <value type="somethingelse">, which would be changing an attribute named type.

AaronKelsey

@JonB Yes you're right, I want to change the text value of the ItemB element.

Would you be able to help me with this?

mrjj

@AaronKelsey
Hi
Sorry first noticed the ChangeThisValueHere :( (thx @JonB)
so setAttribute is not useful in this case.
You want to change a text node/the node text
Please see here
https://stackoverflow.com/questions/6753782/edit-value-of-a-qdomelement