How do I correct PX1011 warning from Acuminator? (it suggests sealing class, but that causes errors in error list)

I needed to add a new field to SOOrder and update attributes of another field. Both classes inherit PXCacheExtension, and both give a PX1011 warning that Because multiple levels of inheritance are not supported for PXCacheExtension, the derived type can be marked as sealed. I had extended it originally from within Acumatica 2018R1 but have moved the code from within the customization project into my Visual Studio Extension Library.

I started with:

public class SOOrderExt : PXCacheExtension<PX.Objects.SO.SOOrder>

If I change the declaration of the class to be:

public sealed class SOOrderExt : PXCacheExtension<PX.Objects.SO.SOOrder>

I get CS0549 SOOrderExt.UsrMyField is a new virtual member in a sealed class 'SOOrderExt'.

Thinking that maybe I missed something and don't need to declare my virtual int?, I commented out:

public virtual int? UsrMyField { get; set; }

and got CS1061 'SOOrderExt' does not contain a definitionfor 'UsrMyField' and no accessible extension method 'UsrMyField; accepting a first argument of type 'SOOrderExt' could be found.

Is the original PX1011 warning something I should ignore, or is there something special needed to follow the guidance to make it sealed or to know that sealing the class is not appropriate?

In short, how do I make these Acuminator warnings go away without simply suppressing and still define my fields?

I'm on 2018R2 Build 18.212.0033 with Visual Studio 2019 Community Edition and Acuminator 1.6.1.

Solution

You need to declare the property but the virtual keyword doesn't seem necessary. Otherwise the warning is an oversight if sealed = no virtual and no virtual = no custom fields.

Without virtual keyword this cache extension seems to be working fine:

public sealed class SOLineExt : PXCacheExtension<PX.Objects.SO.SOLine>
{
    #region UsrField
    [PXDBString(12)]
    [PXUIField(DisplayName="Field")]

    // Ommit declaring the type as virtual
    public /*virtual*/ string UsrField { get; set; }
    public abstract class usrField : PX.Data.BQL.BqlString.Field<usrField> { }
    #endregion
}