"Invalid Class Typecast" Error with Active Record and Enumerated Type #583
Description
1- When you use Active Record and need to insert an enumerated field type then the error below occurs:
Debugger Exception Notification
Project Server.exe raised exception class EInvalidCast with message 'Invalid class typecast'.
The solution for this problem you need to change Ord(aValue.AsInteger) to aValue.AsOrdinal.
Unit: MVCFramework.ActiveRecord
Method: MapTValueToParam
Class: TMVCActiveRecord
Line: 2013
tkEnumeration:
begin
if aValue.TypeInfo = TypeInfo(System.Boolean) then
begin
aParam.AsBoolean := aValue.AsBoolean;
end
else
begin
aParam.AsInteger := aValue.AsOrdinal;
end;
end;
2- Another error occurs when you use Active Record and you need to get an enumerated type field from the database.
Debugger Exception Notification
Project Server.exe raised exception class EInvalidCast with message 'Invalid class typecast'.
type
TThemes = (Light, Dark);
[MVCNameCase(ncLowerCase)]
[MVCTable('sample')]
TSample = class(TMVCActiveRecord)
strict protected
[MVCTableField('theme')]
FTheme: TThemes;
public
[MVCEnumSerialization(estEnumName)]
[MVCSwagJsonSchemaField(stEnumeration, 'theme', 'Theme', True, False, 0, 1)]
property Theme: TThemes read FTheme write FTheme;
end;
TSamples = class(TObjectList<TSample>)
public
class function ReturnItem: TSample;
end;
implementation
class function TSamples.ReturnItem: TSample;
begin
Result := TModel.GetFirstByWhere<TSample>('', [], [], False);
end;
The solution for this problem you need include a new setting when field type is a Enumeration.
Unit: MVCFramework.Serializer.Commons
Line: 1115
Method: MapDataSetFieldToRTTIField
New Lines:
else if (aRTTIField.FieldType.TypeKind = tkEnumeration) then
begin
TValue(AField.AsInteger).ExtractRawData(PByte(Pointer(AObject)) + aRTTIField.Offset);
end
procedure MapDataSetFieldToRTTIField(const AField: TField; const aRTTIField: TRttiField;
const AObject: TObject);
...
begin
...
case AField.DataType of
...
ftInteger, ftSmallint, ftShortint, ftByte:
begin
...
else if (aRTTIField.FieldType.TypeKind = tkEnumeration) then
begin
TValue(AField.AsInteger).ExtractRawData(PByte(Pointer(AObject)) + aRTTIField.Offset);
end
end
...
end;
end;