Title: ObjectFromVariant
Post by: vkorshun on October 17, 2011, 01:55:31 PM
Hi Danijel,
I had some problems with (class function TRtcValueObject.ObjectFromVariant).
My client dataset has TBCDfield. When it was changing I had an error -'Unsupported Variant type.'
I resolved my problem by adding next code
if (TVarData(V).VType = varSQLTimeStamp) or
( TVarData(V).VType = varSQLTimeStampOffset) or
( TVarData(V).VType = varFMTBcd ) then
begin
Result:=TRtcTextValue.Create;
TRtcTextValue(Result).SetText(v);
end
else
raise EConvertError.Create('Unsupported Variant type.');
end;
What is your opinion about this?
Best regards,
Victor Korshun
Title: Re: ObjectFromVariant
Post by: D.Tkalcec (RTC) on October 17, 2011, 05:30:05 PM
The exception message you are getting is correct, because there is no TRtcValueObject descendant which can hold these data types natively and I wouldn't convert all these types to Text silently either, because these conversions need to be known on both sides (sender and receiver). But ... since you have mentioned a dataset and the BCDField, I think your problem is in the "rtcDB.pas" unit and can be solved by extending the "RtcDataSetRowsToDelphi", "DelphiDataSetToRtc" and "DelphiRowToRtc" procedures to handle unsupported types. Please locate the "RtcDataSetRowsToDelphi" procedure in the "rtcDB.pas" unit and replace it, as well as the following 3 procedures, with the code below: procedure RtcDataSetRowsToDelphi(rtcDS:TRtcDataSet; DelphiDS:TDataSet);
var
flds:integer;
fldname:string;
field:TField;
fstream:TStream;
begin
DelphiDS.Active:=True;
rtcDS.First;
while not rtcDS.EOF do
begin
DelphiDS.Append;
for flds:=0 to rtcDS.FieldCount-1 do
begin
fldname:=rtcDS.FieldName[flds];
field:=DelphiDS.FindField(fldname);
if assigned(field) then
if not rtcDS.isNull[fldname] then
if field.isBlob then
begin
fstream:=DelphiDS.CreateBlobStream(field,bmWrite);
try
fstream.CopyFrom(rtcDS.asByteStream[fldname], rtcDS.asByteStream[fldname].Size);
finally
fstream.Free;
end;
end
else
case RTC_FIELD2VALUE_TYPES[rtcDS.FieldType[fldname]] of
rtc_Currency: field.AsCurrency:=rtcDS.asCurrency[fldname];
rtc_DateTime: field.AsDateTime:=rtcDS.asDateTime[fldname];
rtc_String: field.AsString:=rtcDS.asString[fldname];
else field.Value:=rtcDS.Value[fldname];
end;
end;
DelphiDS.Post;
rtcDS.Next;
end;
end;
procedure DelphiDataSetToRtc(DelphiDS:TDataSet; rtcDS:TRtcDataSet; ClearFieldDefs:boolean=True);
var
fdef:TFieldDef;
flds:integer;
fldname:string;
field:TField;
fstream:TStream;
begin
if ClearFieldDefs then
begin
rtcDS.Clear;
for flds:=0 to DelphiDS.FieldDefs.Count-1 do
begin
fdef:=DelphiDS.FieldDefs.Items[flds];
fldname:=fdef.Name;
field:=DelphiDS.FindField(fldname);
if assigned(field) then
if field.FieldKind=fkData then
rtcDS.SetField(fldname,
RTC_DB2FIELD_TYPE(fdef.DataType),
fdef.Size,
fdef.Required);
end;
end;
DelphiDS.First;
while not DelphiDS.EOF do
begin
rtcDS.Append;
for flds:=0 to rtcDS.FieldCount-1 do
begin
fldname:=rtcDS.FieldName[flds];
field:=DelphiDS.FindField(fldname);
if assigned(field) then
if (field.FieldKind=fkData) and not field.IsNull then
if field.isBlob then
begin
fstream:=DelphiDS.CreateBlobStream(field,bmRead);
try
if {$IFNDEF FPC} TBlobField(field).GraphicHeader and {$ENDIF}
( (field.DataType = ftGraphic) or
(field.DataType = ftTypedBinary) ) then
RtcSkipGraphicFieldHeader(fstream);
rtcDS.NewByteStream(fldname).CopyFrom(fstream,fstream.Size-fstream.Position);
finally
fstream.Free;
end;
end
else
case RTC_FIELD2VALUE_TYPES[rtcDS.FieldType[fldname]] of
rtc_Currency: rtcDS.asCurrency[fldname]:=field.AsCurrency;
rtc_DateTime: rtcDS.asDateTime[fldname]:=field.AsDateTime;
rtc_String: rtcDS.asString[fldname]:=field.AsString;
else rtcDS.Value[fldname]:=field.Value;
end;
end;
DelphiDS.Next;
end;
end;
procedure DelphiFieldsToRtc(const DelphiDS:TDataSet; const rtcDS:TRtcDataSet);
var
fdef:TFieldDef;
flds:integer;
fldname:string;
field:TField;
begin
for flds:=0 to DelphiDS.FieldDefs.Count-1 do
begin
fdef:=DelphiDS.FieldDefs.Items[flds];
fldname:=fdef.Name;
field:=DelphiDS.FindField(fldname);
if assigned(field) then
if field.FieldKind=fkData then
rtcDS.SetField(fldname,
RTC_DB2FIELD_TYPE(fdef.DataType),
fdef.Size,
fdef.Required);
end;
end;
procedure DelphiRowToRtc(const DelphiDS:TDataSet; const rtcDS:TRtcDataSet);
var
flds:integer;
fldname:string;
field:TField;
fstream:TStream;
begin
rtcDS.Append;
for flds:=0 to rtcDS.FieldCount-1 do
begin
fldname:=rtcDS.FieldName[flds];
field:=DelphiDS.FindField(fldname);
if assigned(field) then
if (field.FieldKind=fkData) and not field.IsNull then
if field.isBlob then
begin
fstream:=DelphiDS.CreateBlobStream(field,bmRead);
try
if {$IFNDEF FPC} TBlobField(field).GraphicHeader and {$ENDIF}
( (field.DataType = ftGraphic) or
(field.DataType = ftTypedBinary) ) then
RtcSkipGraphicFieldHeader(fstream);
rtcDS.NewByteStream(fldname).CopyFrom(fstream,fstream.Size-fstream.Position);
finally
fstream.Free;
end;
end
else
case RTC_FIELD2VALUE_TYPES[rtcDS.FieldType[fldname]] of
rtc_Currency: rtcDS.asCurrency[fldname]:=field.AsCurrency;
rtc_DateTime: rtcDS.asDateTime[fldname]:=field.AsDateTime;
rtc_String: rtcDS.asString[fldname]:=field.AsString;
else rtcDS.Value[fldname]:=field.Value;
end;
end;
end;
That should solve your problem. Naturally, you should also remove your changes/additions from the "rtcInfo.pas" unit in order to test if the above changes work for you. If it works, then I will release the same changes in the next RTC SDK update (v4.50). Best Regards, Danijel Tkalcec
Title: Re: ObjectFromVariant
Post by: vkorshun on October 17, 2011, 07:23:01 PM
Many thanks.
It works.
Best regards,
Victor Korshun
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