Create missing data on RowSelected - acumatica

Question

We have a graph extension that manages the tab we added to a screen. The tab displays data from our own DAC. We do not use a DAC extension, not going to go into the reasons right now.
When a user opens the main screen I want to create a record of our data if it does not exist, with some defaulting business logic.
I added a RowSelected event handler on the main DAC and it fires as I expect it to. When I add the code to create our missing record in the event handler Acuminator gives me error "PX1044 Changes to PXCache cannot be performed in event handlers."
I understand the error that Acuminator is raising, but I'm not sure where else to create our record. I cannot remember a section of the university specifically addressing this scenario.
Can anyone tell me how I would handle this scenario? And if possible, point me at the learning material that covers this scenario for broader information.

Answer 1

Unfortunatly there are only a few OK ways to do this and make Acuminator happy. You will risk data inconsistency.
https://github.com/Acumatica/Acuminator/blob/master/docs/diagnostics/PX1044.md
I would reccomend putting your data insertion code in Row Updated and hope the user updates something

Answer 2

I got a reply from Acumatica support, you can do this in a view select delegate.
Here's some example code, I haven't tested it though:
public class InventoryItemMaintExtension : PXGraphExtension<InventoryItemMaint>
{
public SelectFrom<MyCustomTable>.
Where<MyCustomTable.inventoryID.IsEqual<
InventoryItem.inventoryID.FromCurrent>>.
View AdditionalItemData;
public static bool IsActive() { return true; }
public IEnumerable additionalItemData()
{
var data = AdditionalItemData.SelectSingle();
if (data is null)
{
data = new MyCustomTable();
AdditionalItemData.Insert(data);
}
return AdditionalItemData.Select();
}
}
[PXCacheName("Additional Item Data")]
[Serializable]
public class MyCustomTable : IBqlTable
{
#region CashAccountID
[Inventory]
[PXDefault]
public virtual int? InventoryID { get; set; }
public abstract class inventoryID : PX.Data.BQL.BqlInt.Field<inventoryID> { }
#endregion
#region Required
[PXDBBool()]
[PXDefault(false)]
[PXUIField(DisplayName = "Required")]
public virtual bool? Required { get; set; }
public abstract class required : PX.Data.BQL.BqlBool.Field<required> { }
#endregion
}