Why RB don't introduce an oleobject component?

rbuser

Hi,

I have a look the FastReport component in these days. Compare with RB, I
find the most interesting component RB don't have is the OleObject
component. FastReport can insert any Ole Object from OleContainer into the
report. That means end-user can import any graph of Excel, Word ... into
the report. It's quite cool. Is it possible DM add this feauture into RB?
Or how I can create my own OleObject RCL component?

Cheers,

Tao

rbuser

I try to write my own RCL OleObject component. And I can't find a way to
save the OleContainer's Stream into Report Template file when I call
ppReport1.Template.Save.

My code is like this:

TtlOleObject = class(TppCustomImage)
...
published
property OleStream: TMemoryStream read GetOleStream write SetOleStream;
end;

procedure TpptlObject.OleEditMenuClick(Sender: TObject);
begin
if (Band = nil) or (Band.Report = nil) then Exit;
begin
FDialog.ShowModal;
PictureChanged(Self);
PropertyChange;
if FDialog.OleContainer1.OleObjectInterface <> nil then
FDialog.OleContainer1.SaveToStream(FOleStream); // Here put the
OleContainer object into a memory stream
end;
end;

And I have read the "Tech Tip: Storing Custom Information with Templates".
It looks like RB just can save the fixed size stream into the Template
header. But how about the unknown size stream?

Cheers,

Tao

rbuser

Hi Tao,

to save any non-published data into the component's storage you have to
override 'DefineProperties'.
Using the templates custom storage isn't the right place for storing
component properties.

HTH,
Chris Ueberall;

rbuser

Hi, Chris

Thanks for your help. Now I copy the Delphi 'DefineProperties' help code,
and change like follow:

type
TppOleObject = class(TppCustomImage)
....

constructor TppOleObject.Create(AOwner: TComponent);
begin
inherited;
FBitmap := TBitmap.Create;
Picture.Bitmap := FBitmap;

FDialog := TFrmOleObjectDlg.Create(Self);

FOleContainer := TOleContainer.Create(Self);
with FOleContainer do
begin
Parent := FDialog;
Visible := False;
Name := 'XXX';
AllowInPlace := False;
AutoVerbMenu := False;
BorderStyle := bsNone;
SizeMode := smClip;
end;
end;

procedure TppOleObject.LoadCompProperty(Reader: TReader);
begin
if Reader.ReadBoolean then
// OleContainer := Reader.ReadComponent(nil);
OleContainer := TOleContainer(Reader.ReadComponent(nil));
end;

procedure TppOleObject.StoreCompProperty(Writer: TWriter);

begin
Writer.WriteBoolean(OleContainer <> nil);
if OleContainer <> nil then
Writer.WriteComponent(OleContainer);
end;

procedure TppOleObject.DefineProperties(Filer: TFiler);

function DoWrite: Boolean;
begin
if Filer.Ancestor <> nil then { check Ancestor for an inherited value }
begin
if TppOleObject(Filer.Ancestor).OleContainer = nil then
Result := OleContainer <> nil
else if (OleContainer = nil) or
(TppOleObject(Filer.Ancestor).OleContainer.Name <>
OleContainer.Name) then
Result := True

else Result := False;
end
else { no inherited value -- check for default (nil) value }
Result := OleContainer <> nil;
end;
begin
inherited; { allow base classes to define properties }

if (FDialog.OleContainer1.OleObjectInterface <> nil) then
begin
FDialog.OleContainer1.Copy;
FOleContainer.Paste;
end;


Filer.DefineProperty('OleContainer', LoadCompProperty, StoreCompProperty,
DoWrite);
end;

I can save the Report Template as Txt and the result like this:

object ppOleObject1: TppOleObject
UserName = 'OleObject1'
MaintainAspectRatio = False
Picture.Data = {07544269746D617000000000}
Dialog = ppOleObject1.FrmOleObjectDlg
mmHeight = 52388
mmLeft = 75936
mmTop = 12700
mmWidth = 56092
BandType = 4
OleContainer = True
TOleContainer = Null
Left = 0
Top = 0
Width = 121
Height = 121
Caption = 'XXX'
AllowInPlace = False
AutoVerbMenu = False
BorderStyle = bsNone
TabOrder = 2
Visible = False
end

I don't understand why the OleContain don't save as other objects like

object OleContainer: TOleContainer
...

Of course, I can read the report template back form the ppDesigner. It
return a 'Read Stream error' exception.

Could you tell me what's wrong with my code, please?

Many thanks!

Tao

rbuser

Hi tao,

I think you should use the same technique as when storing an OLE-object in a
database. Use the streaminig methods of the component, see your own
'TMemoryStream' example. You have to change the 'StoreCompProperty' and
'LoadCompProperty' methods.

HTH,
Chris Ueberall;

rbuser

It looks like I can not store the Ole-object into template together, doesn't
it? At first, I have thinked about store the Oleobject in a blod field.
But just try to make it easy for our support people can just copy a report
template file to the customer and export oleobject from table and import the
oleobject into the database again.

Many thanks!!

Tao