How to make it easier to access json nested object in Qt?

Question

Qt

There is this json

{
   "firstName": "Иван",
   "lastName": "Иванов",
   "address": {
       "streetAddress": "Московское ш., 101, кв.101",
       "city": "Ленинград",
       "postalCode": 101101
   },
   "phoneNumbers": [
       "812 123-1234",
       "916 123-4567"
   ]
}

to change the value of the city key , you have to do the following construction:

QFile j_file( "file.json" );

   if( !j_file.open( QIODevice::ReadOnly | QIODevice::Text ) )
     qDebug() << "Err open file";

   QJsonDocument j_doc = QJsonDocument::fromJson( j_file.readAll() );

   QJsonObject j_obj = j_doc.object();
   QJsonValue j_val = "Piter";
   QJsonObject jo(j_obj["address"].toObject());
   jo["city"] = j_val;
   j_obj["address"] = jo;

In my opinion, it looks somehow clumsy, but if the investment is even deeper ... Tell me how to competently get access to the necessary keys.

Answer 1

I found a function that allows you to easily go to any depth and modify the values.

void parseJson::modifyJsonValue(QJsonObject &obj, const QString &path, const QJsonValue &newValue)
{
  const int indexOfDot = path.indexOf( '.' );
  qDebug() << indexOfDot;
  const QString propertyName = path.left( indexOfDot );
  qDebug() << propertyName;
  const QString subPath = indexOfDot > 0 ? path.mid(indexOfDot + 1) : QString();

  QJsonValue subValue = obj[ propertyName ];

  if(subPath.isEmpty()) {
  subValue = newValue;
  }
  else {
  QJsonObject obj = subValue.toObject();
  modifyJsonValue(obj,subPath,newValue);
  subValue = obj;
  }

  obj[propertyName] = subValue;
  }
  void modifyJsonValue(QJsonDocument& doc, const QString& path, const QJsonValue& newValue) {
  QJsonObject obj = doc.object();
  modifyJsonValue(obj,path,newValue);
  doc = QJsonDocument(obj);
}

Answer 2

XPath.