Loose of datasource

rbuser

I saved a report (with one subreport in it) to a template-file. Afterwards I
reloaded it (within code) and then the datasources of all fields aren't set
any more - maybe it's because I'm creating the report and its pipelines by
hand?

BTW where do I find the tips & tricks or other technical tips? In the
newsgroup I can only see 2 posts so I'd like to have a resource for more
information.

Any ideas?

TIA,
Helge.

rbuser

Hi Helge,

Change your news settings. There is an option to delete a message after x
days, increase that value and reset the group to receive the messages once
more.

regards,
Chris Ueberall;

rbuser

> Change your news settings. There is an option to delete a message after x

Ok, that worked - thanks!

Do you have also a solution to my problem?

Helge.

rbuser

I haven't found a solution yet so I post a bit of source code here - maybe
someone has an idea...

TSpooler = class(TThread)
constructor Create(CreateSuspended: Boolean);
destructor Destroy; override;

procedure UpdateStatus;
procedure GetNextItem;
procedure PrintItem;
procedure Execute; override;

private
ActEntry : TSpoolEntry;

public
RBuilderContainer : TComponent;
MasterTable : TDbf;
MasterSource : TDataSource;
MasterPipeline : TppDBPipeline;
DetailTable : TDbf;
DetailSource : TDataSource;
DetailPipeline : TppDBPipeline;
Report : TppReport;
ReportDesigner : TppDesigner;
end;

constructor TSpooler.Create(CreateSuspended: Boolean);
begin
inherited Create(true);

RBuilderContainer := TComponent.Create(nil);
MasterTable := TDbf.Create (RBuilderContainer);
MasterSource := TDataSource.Create (RBuilderContainer);
MasterPipeline := TppDBPipeline.Create (RBuilderContainer);
DetailTable := TDbf.Create (RBuilderContainer);
DetailSource := TDataSource.Create (RBuilderContainer);
DetailPipeline := TppDBPipeline.Create (RBuilderContainer);
Report := TppReport.Create (RBuilderContainer);

Report.DeviceType := dtScreen;

ReportDesigner := TppDesigner.Create (RBuilderContainer);
ReportDesigner.Caption := 'Beleg-Designer';
ReportDesigner.Report := Report;

MasterTable.ReadOnly := true;
MasterTable.OpenMode := omAutoCreate;
MasterTable.FilePath := DataPath;
DetailTable.ReadOnly := true;
DetailTable.OpenMode := omAutoCreate;
DetailTable.FilePath := DataPath;

MasterSource.DataSet := MasterTable;
DetailSource.DataSet := DetailTable;
MasterPipeline.DataSource := MasterSource;
MasterPipeline.UserName := 'Hauptdatenstrom';
DetailPipeline.DataSource := DetailSource;
DetailPipeline.UserName := 'Detaildatenstrom';

if not CreateSuspended then Resume;
end;

destructor TSpooler.Destroy;
begin
ReportDesigner.Free;
Report.Free;
DetailPipeline.Free;
MasterPipeline.Free;
DetailSource.Free;
DetailTable.Free;
MasterSource.Free;
MasterTable.Free;

inherited;
end;

procedure TSpooler.PrintItem;
begin
try
Synchronize(UpdateStatus);
except
on e:Exception do MessageDlg (e.ClassName+#13+e.Message, mtError,
[mbOk], 0);
end;
MasterTable.TableName := ActEntry.SpoolingNumber + '-master.dbf';
DetailTable.TableName := ActEntry.SpoolingNumber + '-detail.dbf';
if not FileExists (DataPath + '\' + DetailTable.TableName) then
DetailTable.TableName := '';

try
Report.Template.FileName := TemplatePath + ActEntry.BelegFormular +
'.rtm';
Report.Template.LoadFromFile;
except
on E:Exception do
MessageDlg ('Vorlage nicht gefunden!'+#13+e.ClassName+#13+e.Message,
mtError, [mbOk], 0);
end;
try
Report.PrinterSetup.PrinterName := 'Screen';
Report.DataPipeline := MasterPipeline;

if not ActEntry.DesignMode then
Synchronize (Report.Print)
else
Synchronize (ReportDesigner.ShowModal);

except
on E:Exception do
MessageDlg ('Druckvorgang fehlgeschlagen'+#13+e.ClassName+#13+e.Message,
mtError, [mbOk], 0);
end;
end;

My first thoughts were that the whole system might get in trouble when not
having a valid parent so I came to the solution with the TComponent...

My problem is that no matter if the Designer or the Preview is shown, all
fields on the report loose their datasource ... I create the rtm-files with
the Designer and save them - it is always the same table (or better: with
the same content) and as soon as I set "Hauptdatenstrom" in the Designer as
each field's datasource, all data is shown correctly. So it isn't the proble
with the datalink itself - it's only that the ReportBuilder doesn't connect
the datasources from the template properly.

I got the hint to look in the Developers Guide but I have two differences:
1. I'm using a template and don't create all by hand and 2. I'm in a thread
(if that matters so much).

Has anybody an idea? I need it quick, if possible!

BTW I use Delphi 5 with SP1, RB 6.02 Enterprise Demo on Windows XP final -
German versions.

TIA,
Helge.

digitalmetaphors

The datapipelines just need to be reassigned to the report and subreports.
Rb will search all of the forms and datmodules inthe application, looking
for data pipelines by name.

When you save a report, it saves a string property for the datapipeline
name. (This was done to fix some Delphi 6 support issues in the Delphi 6
IDE) In order to resolve the string into a datapipeline object reference,
RB performs this search of the application for visible datapipeline objects.
If none can be found, then the datapipeline refernce isn't going to get set,
and this is probably the behavior you are getting.

I think that RB is not able to find the datapipelines since they are owned
by a TComponent instance with a nil owner. You'll need to manually assign
the datapipeline's to the report, after you load a template. You can loop
through the report looking for subreport components, in order to hook their
datapipeline property up, also. There is a ReportObjectLoop article in the
TechTips newsgroup in the CodeBased thread. You'll need to check if a
report Object is TppSubreport in that example. The data aware controls
should be automatically reassigned to the datapipeline when the
report/subreport is reconnected.


Cheers,

Jim Bennett
Digital Metaphors

rbuser

> I think that RB is not able to find the datapipelines since they are owned

Do I understand you right? If I make them all a owner of Application, RB
will find them?

their
the

Ok, but I've sometimes more than one pipelines - I can't decide which one is
the right one for every control :-(

But thanks for the explanation, I'll try it out in a second...

Helge.

digitalmetaphors

I should say, that normally, a form or datamodule is the datapipeline's
owner.


Cheers,

Jim Bennett
Digital Metaphors

rbuser

> Do I understand you right? If I make them all a owner of Application, RB

It works! It works! I could kiss you ;-)

Many, many thanks for the hint! I though about that, too - the reason why
that container was there... but I thought the report iterate from bottom to
top but it it does it the other way around which is indeed more logical *g*
So it was somehow my fault (as I assumed before)...

Thanks again,
Helge.