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