VerifyContainer only works with externally stored containers. From the info in FileMaker Help, it would appear that a result of 0 would indicate an empty externally stored container field. But simply changing the file will also produce a 0 result so this doesn't look like a function that you can use to check for an empty container field. A ? result indicates an error due to referring to a field that is not a container field.
If ( Not IsEmpty ( RDS_Room_Diagram ) ; "X" )
Which will work with all storage options you might select for a container field.
Lovely that worked
Thank you very much
I had a strange situation today. A couple externally stored image container records were showing "<missing: filename.jpg>" instead of the thumbnail. The VerifyContainer function was showing boolean True for these and all other container records. For the missing ones, I expected VerifyContainer to be False.
I fixed the problem by exporting or dragging the image out of the container and then back in and all was well.
Viewing the actual RC content, I see the missing file (since deleted) and its replacement.
Odd. Perhaps "valid" in that the file existed, but the thumbnail was somehow lost?