BarsPeriod.ToXml() not serializing all fields in BarsPeriod

[tcdouglas]

I have implemented IIntervalProvider on my custom NTTabPage and overridden Save(XElement element) and Restore(XElement element) as follows:

private BarsPeriod _barsPeriod;
public BarsPeriod BarsPeriod
{
    get => _barsPeriod;
    set
    {
        if (!EqualityComparer<BarsPeriod>.Default.Equals(_barsPeriod, value))
        {
            TheIntervalSelector.Interval = _barsPeriod = value;

            RefreshHeader();
            PropagateIntervalChange(value);
        }
    }
}

private void TheIntervalSelector_OnIntervalChanged(object sender, BarsPeriodEventArgs e)
{
    BarsPeriod = e.BarsPeriod;
}

protected override void Save(XElement element)
{
    if (element == null)
        return;

    // save the currently selected interval
    if (BarsPeriod != null)
    {
        var intervalElement = new XElement("Interval");
        BarsPeriod.ToXml(intervalElement); // does not serialize BarsPeriod.BarsPeriodType because the property is adorned with XmlIgnore!!!
        element.Add(intervalElement);
    }
}

protected override void Restore(XElement element)
{
    if (element == null)
        return;

    // restore the previously selected interval
    XElement intervalElement = element.Element("Interval");
    if (intervalElement != null && !string.IsNullOrEmpty(intervalElement.Value))
        BarsPeriod = BarsPeriod.FromXml(intervalElement); // does not deserialize BarsPeriod.BarsPeriodType because the property is adorned with XmlIgnore!!!
}​

Notice the above code is using BarsPeriod.ToXml(intervalElement) to serialize the BarsPeriod provided by the IntervalSelector.

However, because BarsPeriod.BarsPeriodType is adorned with the XmlIgnore attribute it is not serialised. This results in incorrect IntervalSelector state when the workspace is restored:

IntervalSelector with 10 Seconds selected:



BarsPeriod properties at the point of serialization:




BarsPeriod serialized XML:



Because of the above, after the workspace is restored the IntervalSelector now shows 10 Minutes selected, not 10 Seconds:



So how are you supposed to save and restore the BarsPeriod provided by the IntervalSelector?

[NinjaTrader_Jesse]

Hello tcdouglas,

I see that happening with the addon sample as well, I will need to report that to see if that is intended to if some other process of saving is required. Once I have more details on that I will reply back here.

[NinjaTrader_Jesse]

Hello tcdouglas,

It looks like that is to be expected, most controls do not automatically save their values such as the interval selector. You would have to make your own xml node and save the data/restore the data. You can find a sample of saving custom values here. https://forum.ninjatrader.com/forum/...830#post759830

[tcdouglas]

hmm, ok, so the BarsPeriod has it's own ToXml() and FromXml() for saving/restoring it's own state, but they don't save/restore it's own state completely so they are of no use!

As you suggest, I'll implement my own BarsPeriod persistence, but it's not as straight forward as it could be because XmlIgnore attribute is adorned on some BarsPeriod properties!

Just an FYI: Because NTTabPage Save() and Restore() are used when duplicating a tab, the IntervalSelector's selection changes from Seconds to Minutes when duplicating a tab (as well as saving/restoring workspaces)