As an adjunct to my previous post. When moving data from a json object into a struct, and where members are missing or null, then the pbRequireAllMembers might also set the elements to null. Maybe this would require a separate property to handle something like this? Of course this would only be useful if we can then test that a struct element is not null.

BTW I note the improvement in the pbRequireAllMembers property in DataFlex 19.1 as highlighted by the sample code below. In DataFlex 19.0 this would trigger error 4529, Invalid Json Object. Expected …... and require the json object to be pre-processed i.e. remove the null members before calling JsonToDataType.

Code:
Procedure Json2Struct
    tStudent Student
    Boolean bSuccess
    Handle hoJson
    
    Get Create (RefClass(cJsonObject)) To hoJson
    Get ParseString Of hoJson '{ "name": "George", "details": { "birthday": null, "age": null, "male": true, "scholar": null }, "ratings": [ null ] }' To bSuccess
    If (bSuccess) Begin
        Set pbRequireAllMembers Of hoJson To False
        Get JsonToDataType Of hoJson To student
    End
    Else Begin
        Send ReportParseError Of hoJson
    End
    
    Send Destroy Of hoJson
End_Procedure