Best way to store downloaded XmlModel in LocalStorage with qml

The step with the db is only neccessary bcause i was not sure how to add elements to an existing xml document. I think QDomDocument does this job, so i can directly update a xml file. What about images? Would you download them and put them in a folder, or is there an easier way with QAbstractNetworkCache, QNetworkDiskCache, QDeclarativeImageProvider? They all seem quite complicated or limited and i think simply downloading images and store them in a folder seems more easy.