Load TppReport from an DLL / preview in mz own TppViewer

rbuser

Hello

I?ll load an report from an dll. That means I call an exportet function from
the application and
get the called report (from type TppReport). Now I?ll, that the report will
be shown in my own
preview (an TppViewer - Component) which is on my own form on application -
site. But an error will be raised...:

This function calls the exported function from the DLL:

function TModReports.genReport2D(pParameters : String) : Boolean;
var tMSG : String;
begin
try
....
if not Assigned (FActivePreview) then
begin
FActivePreview := ReportFrame.rbViewer;
end;

If Not Assigned(FactiveReport) then
FactiveReport := TppReport.Create(nil);

createXMLFileExpressions();
generateXMLExpressionList();

FActiveReport.DeviceType := 'Screen';
FActiveReport.PrinterSetup.PrinterName := 'Screen';
FActiveReport.ModalPreview := False;

with getFwApp.PM.Project do
FActiveReport := getReport2D_KPSA(getFwApp.RootDir,
FTempExpressions,
get2DGlobals.PlanningArea,

Plannings[CurrentPlanning].ScaleFactor,
getFwApp.Printer.PrinterName,
getFwApp.Printer.PaperName);
/// If I omit the line above there no error raised but the report is
/// shown in the standard report builder-preview
FActiveReport.PrintToDevices;
/// here the report should be shown in my own TppViewer
/// but an error is raised:
/// EConvertError with Message Cannot assign a TppPage to a TppPage
...
end;
except
end;
...

The exported function from the DLL:

function getReport2D_KPSA(pAppPath : String;pDBExpressionsPath: String;
pPlanArea: FVector2;
pScale: Double;pPrinterName : String;
pPaperSize : String): TppReport;stdcall;
begin
Result := nil;
FPlanArea := pPlanArea;
Scale := pScale;
Fexpr_db := pDBExpressionsPath;

if Assigned(frm_controlcenter) then
FreeAndNil(frm_controlcenter);
frm_controlcenter := Tfrm_controlcenter.Create(nil);

if not Assigned(frm_controlcenter.rbReport) then
frm_controlcenter.rbReport := TppReport.Create(nil);

if FileExists(pDBExpressionsPath) then
begin
frm_controlcenter.cdsExpressions.FileName := pDBExpressionsPath;
end;

with frm_controlcenter.rbReport do
begin
CachePages := False;
DeviceType := 'Screen';
DataPipeline := frm_controlcenter.ppDBPipeExpressions;
ModalPreview := False;
PassSetting := psOnePass;
PrinterSetup.PrinterName := pPrinterName;
PrinterSetup.PaperName := pPaperSize;
SavePrinterSetup := True;
Template.FileName := pAppPath + '\etc\reports\2d\default_2d.rtm';
Template.Load;
end;

Result := frm_controlcenter.rbReport;
end;
~~~~~~~~~~~~~~~~~~~~~~~~~~~

You know what I mean? I?ll get the report loaded from an DLL shown in my own
TppViewer. In the examples of reportbuilder an function is called from an
dll but
it is previewed it in the preview on the form assigned in the dll...

What I?ll is to preview an report - transfered from an dll to the
application - in my own preview...

Regards,

Hoffmann, Jan

digitalmetaphors

One possible problem could be that you are calling Load to load the template
into the report which uses the template's SaveTo property. This does default
to stFile but it is possible that it could be set to something else. Use
LoadFromFile isntead to make that explicit. One thing to make sure is to
preview the report within the called method rather than the calling method
to make sure that the report is being loaded and set up properly. I've
included a sample project which has a simple method that returns a reference
to a report via a function called in the DLL. There is another method which
frees the reference.

< The sample project is available from
www.digital-metaphors.com/tips/DLLReport.zip >

--
Cheers,

Alexander Kramnik
Digital Metaphors