Game Programming Using Qt

Time for action – implementing a JSON parser

Let's extend the PlayerInfoJSON class and equip it with a reverse conversion:

PlayerInfo PlayerInfoJSON::readPlayerInfo(const QByteArray &ba) const {
  QJsonDocument doc = QJsonDocument::fromJson(ba);
  if(doc.isEmpty() || !doc.isArray()) return PlayerInfo();
  return readPlayerInfo(doc.array());
}

First, we read the document and check whether it is valid and holds the expected array. Upon failure, an empty structure is returned; otherwise, readPlayerInfo is called and is given QJsonArray to work with:

PlayerInfo PlayerInfoJSON::readPlayerInfo(const QJsonArray &array) const {
  PlayerInfo pinfo;
  foreach(QJsonValue value, array)
    pinfo.players << readPlayer(value.toObject());
  return pinfo;
}

Since the array is iterable, ...