How to replace a word between two elements in a XML file

Brikinhos

Hi, i'm working with the class QRegExp and i need to replace a word between two elements in a XML file, for example, i have this text

<Vars>
</Vars>
<Code>
    cvNamedWindow("ventana_con_AUTOSIZE",1);
	cvShowImage("ventana_con_AUTOSIZE", image);
 	cvWaitKey(0);
	cvReleaseImage(&image);
</Code>

I need to replace the ampersand, or all ampersands, to & amp; between <Code> and </Code>, never before <Code> or after </Code>. I tried this

QRegExp re_code"(?:<Code>)(?:.*)&(?!amp;)(?=.*</Code)"

but it doesn't work, it replaces from <Code> to &. The result is this:

<Vars>
</Vars>
&amp;image);
</Code>

I want to do the same with >, < and all illegal characters of XML that they have to be escaped.

Thanks in advance

koahnig

@Brikinhos
I am not sure of how you like to replace the character.
However, to me it looks that your match of QRegExp is not correct. It is:

<Code>
    cvNamedWindow("ventana_con_AUTOSIZE",1);
    cvShowImage("ventana_con_AUTOSIZE", image);
    cvWaitKey(0);
    cvReleaseImage(&

If you replace this, the result is logical. The result of your regular expression you can easily check if you are using the QRegExp example.

Brikinhos

@koahnig I replace it using this piece of code

    QFile f(dir);
    if(!f.open(QIODevice::ReadOnly)) {
        QMessageBox::information(0, "error", f.errorString());
    }
    QTextStream in(&f);
    QString text= in.readAll();
    QRegExp re_code("(?:<Code>)(?:.*)&(?!amp;)(?=.*</Code)");
    text = text.replace(re_codigo,"&amp;");

koahnig

@Brikinhos
The problem is the match as already described in my previous reply.

    QRegExp re_code("((?:<Code>)(?:.*))(&)(?!amp;)(?=.*</Code)");
    text = text.replace(re_code, re_code.cap(1) +"&amp;");

You may want to try the code above. I have changed the last two lines only of your code block.
The text replaced is still the same, but it adds the part which is missing.
Note: this brain to keyboard and not really tested. It is not elegant in my opinion, but it is the only solution I see at the moment. Maybe someone with more regex experience has a better solution.

Brikinhos

@koahnig Hi, i did something that it works, but is a botched job xD, maybe it is usefull for anyone who reads this post. Now i can lie to Sax parse

    QRegExp re_amp("&(?!.*<Code>)(?=.*</Code>)");
    text.replace(re_amp,"&amp;");

//    QRegExp re_lt("(?!.*<Code>)<(?=.*</Code>)"); This works but i don't know why 

    QRegExp re_lt("<(?!.*<Code>)(?=.*</Code>)");
    text.replace(re_lt,"&lt;");

    QRegExp re_lt_fix("&lt;(?=Code>)");
    text.replace(re_lt_fix,"<");

    QRegExp re_gt(">(?!.*<Code>)(?=.*</Code>)");
    text.replace(re_gt,"&gt;");

    QRegExp re_gt_fix("<Code&gt;");
    text.replace(re_gt_fix,"<Code>");

I tried to use QRegularExpression but it works different, I'll try again in a future. Thank you very much anyway.

Nominate our 2022 Qt Champions!

How to replace a word between two elements in a XML file