Hi,
I will try to answer to the best of my knowledge, but at the same time you may consider direct request to Support via the https://support.smartbear.com/message/?prod=TestComplete form (with the reference to this thread).
TanyaYatskovska : Tanya, could you please draw attention of someone from Support to assist us here?
Also, I assume that you read the https://support.smartbear.com/testcomplete/docs/app-testing/open-apps/index.html help section.
> do I need to have a data grill mapped in NameMapping?
No, not necessarily.
> Will this Debug information work if I search for an object with .find()
Yes, it should. As long as the object is accessible to TestComplete (i.e. is visible in the ObjectBrowser/Object Spy) you should be able to either NameMap it, or to search it via .FindXXX() method, or address it directly.
> Is that enough? (Screenshot_02)
Yes, it is enough to my knowledge. Though Support might provide more details.
> When you try to call this property from the "Object Spy" on the data grid, an error flashes (marked with an arrow in the screenshot).
I think this is because your control is inherited one and Development did not implement all requirements to full extent. Either talk to them or, hope, Support will point to the missed part more precisely.
> I need to add this property to the list (I can't see it right now).
I see the situation like this (my vision may be incorrect and I hope that Support will correct or extend it where needed):
-- TestComplete picked-up the information that you added to the Object Mapping panel and correctly identified your control as a descendant of the DevExpress Quantum Grid;
-- TestComplete 'knows' that DevExpress Quantum Grid must have the wViewCount property and tried to access it in your control;
-- TestComplete failed to access the wViewCount property in your control due to the lack of the provided (debug) support from Development. This is the reason of the error shown in the Object Spy and why the property is absent in the properties list in NameMapping.