CODEWITHSUNDEEP
jsonqtqstring
sark9012
sark9012

Reputation: 5747

Turn QString to JSON

I have the following:

QString notebookid = ui->notebookid->toPlainText();
QString tagid = ui->tagid->toPlainText();
QString userid = ui->userid->toPlainText();
QString subject = ui->subject->toPlainText();
QString comment = ui->comment->toPlainText();

I need to turn them into JSON, where the key is the notebookid, tagid, etc and the value is in the ui->notebookid, etc.

What's the best way to go about doing this?

Thanks.

Upvotes: 0

Views: 4876

Answers (2)

Kuba hasn't forgotten Monica
Kuba hasn't forgotten Monica

Reputation: 98505

In Qt 5, you can use QJsonObject. One way is to explicitly select the controls to serialize:

QJsonObject MyDialog::serialize() const {
  QJsonObject json;
  json.insert("notebookid", ui->notebookid->toPlainText());
  ...
  return json;
}

Another way is to have a generic serializer that uses the Qt's metadata. Each named control's user property is then serialized:

QJsonObject serializeDialog(const QWidget * dialog) {
    QJsonObject json;
    foreach (QWidget * widget, dialog->findChildren<QWidget*>()) {
        if (widget->objectName().isEmpty()) continue;
        QMetaProperty prop = widget->metaObject()->userProperty();
        if (! prop.isValid()) continue;
        QJsonValue val(QJsonValue::fromVariant(prop.read(widget)));
        if (val.isUndefined()) continue;
        json.insert(widget->objectName(), val);
    }
    return json;
}

You can convert QJsonDocument to text as follows:

QJsonDocument doc(serializeDialog(myDialog));
QString jsonText = QString::fromUtf8(doc.toJson());

Unfortunately, Qt 5's json code requires a bunch of changes to compile under Qt 4.

Upvotes: 0

Roger Attrill
Roger Attrill

Reputation: 396

I'll answer this based on the fact that you were using Qt 4.8 and would not have the QJsonObject available from Qt5.

I use QJSON for exactly this. It's an easy-to-use library using QVariants to parse and serialize the data.

This would be how you'd turn your data into json using QJSON:

QVariantMap jsonMap;
jsonMap.insert("notebookid", notebookid);
jsonMap.insert("tagid", tagid);
jsonMap.insert("userid", userid );
jsonMap.insert("subject", subject );
jsonMap.insert("comment", comment);

QJson::Serializer serializer;
bool ok;
QByteArray json = serializer.serialize(jsonMap, &ok);
assert (ok);

Upvotes: 1

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