how to load and save the combobox values in XML

[sankarapandiyan]

I have done the code by using QSettings apart from this i want to load and save the combobox by using XML i tried a lot but i dnt find any result

thanks in advance.

[koahnig]

@sankarapandiyan

Did you check out Qt's XML examples?

[sankarapandiyan]

yes @koahnig i am cleared in the example but cant implemnt in my code

[koahnig]

@sankarapandiyan

Well, my personal opinion is that you will have a lot of overhead there. However, that is the XML functionality provided by Qt.

You may want to explain why you got stuck. Possibly someone can help.

[VRonin]

You can use the "Model Serialisation" module of this library to save and load the QCombobox::model. After you have done that you'll just need to prepend an element containing the current index:

#include <QApplication>
#include <QPushButton>
#include <QLabel>
#include <QComboBox>
#include <QXmlStreamWriter>
#include <QXmlStreamReader>
#include <XmlModelSerialiser>
#include <QVBoxLayout>
#include <QDebug>
QString saveCombo(const QComboBox* combo){
    XmlModelSerialiser modelSerialiser(combo->model());
    modelSerialiser.setPrintStartDocument(false);
    QString result;
    QXmlStreamWriter writer(&result);
    writer.writeStartElement("combobox");
    writer.writeStartElement("currentIndex");
    writer.writeCharacters(QString::number(combo->currentIndex()));
    writer.writeEndElement(); //currentIndex
    writer.writeStartElement("comboModel");
    modelSerialiser.saveModel(writer);
    writer.writeEndElement(); //comboModel
    writer.writeEndElement(); //combobox
    return result;
}
void loadCombo(QComboBox* combo, const QString& data){
    QXmlStreamReader reader(data);
    int currIdx = -1;
    XmlModelSerialiser modelSerialiser(combo->model());
    QString modelData;
    while (!reader.atEnd() && !reader.error()) {
        switch(reader.readNext()){
        case QXmlStreamReader::StartElement:
            if(reader.name()=="currentIndex")
                currIdx = reader.readElementText().toInt();
            else if(reader.name()=="comboModel"){
                reader.readNextStartElement();
                modelSerialiser.loadModel(reader);
            }
            break;
        default:
            break;
        }
    }
    if(reader.error())
        qDebug() << reader.errorString();
    combo->setCurrentIndex(currIdx);
}

int main(int argc, char **argv) {
    QApplication app(argc, argv);
    QWidget mainWid;
    QVBoxLayout *mainlay = new QVBoxLayout(&mainWid);
    mainlay->addWidget(new QLabel("Save This",&mainWid));
    QComboBox* example = new QComboBox(&mainWid);
    example->addItem("a");
    example->addItem("b");
    example->addItem("c");
    mainlay->addWidget(example);
    mainlay->addWidget(new QLabel("Load This",&mainWid));
    QComboBox* loadedCombo = new QComboBox(&mainWid);
    mainlay->addWidget(loadedCombo);
    QPushButton* testButton = new QPushButton("Test",&mainWid);
    QObject::connect(testButton,&QPushButton::clicked,[example,loadedCombo](){
        const QString savedCombo = saveCombo(example);
        qDebug() << savedCombo;
        loadCombo(loadedCombo,savedCombo);
    });
    mainlay->addWidget(testButton);
    mainWid.show();
    return app.exec();
}

[sankarapandiyan]

thanks a lot @VRonin