QJson changing 1 key inside json file

Kris Revi

void DeviceData::write(int row, QString entryName, QString Value)
{
    QFile file(mJsonFile);

    file.open(QIODevice::ReadOnly | QIODevice::Text);
    QJsonParseError JsonParseError;
    QJsonDocument JsonDocument = QJsonDocument::fromJson(file.readAll(), &JsonParseError);
    file.close();

    QJsonObject RootObject = JsonDocument.object();
    QJsonArray Array = RootObject.find("Device")->toArray();
    RootObject = Array[row].toObject();
    RootObject[entryName] = Value;
    Array[row] = RootObject;
    RootObject["Device"] = Array;

    JsonDocument.setObject(RootObject);
    file.open(QFile::WriteOnly | QFile::Text | QFile::Truncate);
    file.write(JsonDocument.toJson());
    file.close();
}

This changes the line inside the entry it's in OK but for some reason it also adds a totaly new entry at the bottom outside the Device : []

{
    "Device": [
        {
            "IPA": "studiolights",
            "Icon": "fa_address_book",
            "Name": "Nameless",
            "Status": "online",
            "Type": "Strip",
            "UVLights": false
        },
        {
            "IPA": "vitrineskap",
            "Icon": "fa_asterisk",
            "Name": "Vitrineskap",
            "Status": "online",
            "Type": "Strip",
            "UVLights": false
        }
    ],
    "IPA": "studiolights",
    "Icon": "fa_address_book",
    "Name": "Nameless",
    "Status": "online",
    "Type": "Strip",
    "UVLights": false
}

what am i doing wrong?

Christian Ehrlicher

@Kris-Revi said in QJson changing 1 key inside json file:

RootObject

You use this object for two different aspects of your code.

Kris Revi

@Christian-Ehrlicher

void DeviceData::write(int row, QString entryName, QString Value)
{
    QFile file(mJsonFile);

    file.open(QIODevice::ReadOnly | QIODevice::Text);
    QJsonParseError JsonParseError;
    QJsonDocument JsonDocument = QJsonDocument::fromJson(file.readAll(), &JsonParseError);
    file.close();

    QJsonObject RootObject = JsonDocument.object();
    QJsonObject RootObject2 = JsonDocument.object();
    QJsonArray Array = RootObject.find("Device")->toArray();

    RootObject = Array[row].toObject();

    RootObject[entryName] = Value;
    Array[row] = RootObject;

    RootObject2["Device"] = Array;

    JsonDocument.setObject(RootObject2);
    file.open(QFile::WriteOnly | QFile::Text | QFile::Truncate);
    file.write(JsonDocument.toJson());
    file.close();
}

i did this! it works but could i've done it better?

Christian Ehrlicher

I still don't get what you want. When you look at your code you see that you still add 'Value' to the RootObject for now reason which is the cause for your 'wrong' json

Unsolved QJson changing 1 key inside json file