Skipping Detail Records

rbuser

I've tried to implement skipping of detail records based on a certain
condition, as done in demo #116. However, the problem is when the last
record should be skipped, there are problems.

For example, see demo #116. Edit the BIOLIFE demo database, and add a new
record, where the "Common_Name" field begins with an 'S'. Then, run demo
#116. The report generates an infinite amount of pages, until you click
"Cancel". Is there a bug with the approach in demo #116? Everything seems
to work OK with this way of doing things, unless the last record in the
dataset should be skipped.

digitalmetaphors

The demo was checking Category in the SkipForward and Common_Name in
SkipBackward, which obviously is a mistake on our part. They should both be
checking Category to get the 18 records as the form states. The last
record's category value is Smelt, which starts with an S. In the while
loops, there are checks for EOF or BOF so that an infinite loop is not
incurred. It will work correctly if they are both set to Category. Sorry
and thanks for pointing this out.


Cheers,

Jim Bennett
Digital Metaphors

rbuser

The problem I'm still having is when no records should be returned in the
report, it still prints out the last record in the dataset. I've followed
along with the demo at:

http://www.digital-metaphors.com/tips/NoDetailOnSkipRecords.zip

under the "Skipping Records Advice" thread, but my report is set up with
groups. So, when there are no records to print, my group header and group
footer are still printed. What I'm after is to get the "No Records to
Print" message on my report in this case.

How can this be accomplished?

Thanks.

digitalmetaphors

When no records exist in your dataset, you need to set the
Report.NoDataBehaviors property to [ndBlankPage].


Cheers,

Jim Bennett
Digital Metaphors

rbuser

That is the correct advide when the DataSet's RecordCount = 0, but there ARE
records in my dataset, I'm just skipping through them, with the
"NoDetailOnSkipRecords.zip" demo. My group header and footer are still
printed in the case where there are records in my dataset, but according to
my filter criteria, no records should be returned in the report.

digitalmetaphors

Here is the code to do what you want. Basically, check for no data around
the skipping logic, then disable all of the bands. To show the no data
message: add a draw command to the page when all the records have been
skipped as shown below:


unit dm0116;

interface

uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls, dmUtil, ppClass, ppBands, ppCache, ppCtrls, ppComm, ppReport,
ppPrnabl, ppDB, ppDBBDE, Db, DBTables, ppStrtch, ppMemo, ppProd, ExtCtrls,
ppDBPipe, ppVar, ppRelatv, Grids, DBGrids;

type
Tfrm0116 = class(TdmCustomForm)
ppReport1: TppReport;
ppReport1Header: TppHeaderBand;
ppReport1Shape1: TppShape;
ppReport1Label1: TppLabel;
ppReport1Label2: TppLabel;
ppReport1Label3: TppLabel;
ppReport1Label4: TppLabel;
ppReport1Label5: TppLabel;
ppReport1Label6: TppLabel;
ppReport1Detail: TppDetailBand;
ppReport1Shape4: TppShape;
ppReport1Shape5: TppShape;
ppReport1Shape6: TppShape;
ppReport1Shape3: TppShape;
ppReport1Shape2: TppShape;
ppReport1DBMemo1: TppDBMemo;
ppReport1DBText1: TppDBText;
ppReport1DBImage1: TppDBImage;
ppReport1DBText2: TppDBText;
ppReport1DBText3: TppDBText;
ppReport1Footer: TppFooterBand;
ppReport1Group1: TppGroup;
ppReport1GroupHeader1: TppGroupHeaderBand;
ppReport1GroupFooter1: TppGroupFooterBand;
ppReport1Shape7: TppShape;
ppReport1Label7: TppLabel;
ppReport1DBCalc1: TppDBCalc;
ppReport1Line1: TppLine;
Table1: TTable;
DataSource1: TDataSource;
ppBDEPipeline1: TppBDEPipeline;
Label1: TLabel;
Label2: TLabel;
Label3: TLabel;
RadioGroup1: TRadioGroup;
Button1: TButton;
ppReport1Calc1: TppSystemVariable;
ppReport1Calc2: TppSystemVariable;
Database1: TDatabase;
DBGrid1: TDBGrid;
procedure ppBDEPipeline1First(Sender: TObject);
procedure ppBDEPipeline1Last(Sender: TObject);
procedure ppBDEPipeline1Next(Sender: TObject);
procedure ppBDEPipeline1Prior(Sender: TObject);
procedure Button1Click(Sender: TObject);
procedure ppReport1BeforePrint(Sender: TObject);
procedure ppReport1HeaderBeforePrint(Sender: TObject);
procedure ppReport1DetailBeforePrint(Sender: TObject);
procedure ppReport1FooterBeforePrint(Sender: TObject);
procedure ppReport1GroupFooter1BeforePrint(Sender: TObject);
procedure ppReport1GroupHeader1BeforePrint(Sender: TObject);
procedure ppReport1EndPage(Sender: TObject);
private
FNoData: Boolean;
FSkipping: Boolean;

procedure SkipBackward;
procedure SkipForward;

protected
function GetReport: TppProducer; override;
procedure Init; override;
public
{ Public declarations }
end;

var
frm0116: Tfrm0116;

implementation

{$R *.DFM}

uses
ppDevice, ppDrwCmd, ppTypes;

procedure Tfrm0116.Init;
begin
AssignViewer := True;
DisplayForm := True;
end;

function Tfrm0116.GetReport: TppProducer;
begin
Result := ppReport1;
end;

procedure Tfrm0116.Button1Click(Sender: TObject);
begin
{notify report that state of data has changed}
ppReport1.Reset;

{print the report}
ppReport1.PrintToDevices;
end;

procedure Tfrm0116.SkipForward;
var
lbCheckForNoRecords: Boolean;
begin

if RadioGroup1.ItemIndex = 0 then Exit;

if FSkipping then Exit;

if Table1.EOF then Exit;

FSkipping := True;

if (ppdaFirstRecord in ppBDEPipeline1.State) then
lbCheckForNoRecords := True
else
lbCheckForNoRecords := False;

if RadioGroup1.ItemIndex = 1 then
begin
while not(Table1.EOF) and
(Copy(Table1.FieldByName('Category').AsString, 1, 1) = 'S') do
ppBDEPipeline1.Skip;
end

else if RadioGroup1.ItemIndex = 2 then
begin
while not(Table1.EOF) do
ppBDEPipeline1.Skip;
end;

if lbCheckForNoRecords and (ppdaLastRecord in ppBDEPipeline1.State) then
FNoData := True;

FSkipping := False;
end;

procedure Tfrm0116.SkipBackward;
begin
if RadioGroup1.ItemIndex = 0 then Exit;

if FSkipping then Exit;

if Table1.BOF then Exit;

FSkipping := True;

while not(Table1.BOF) and (Copy(Table1.FieldByName('Category').AsString,
1, 1) = 'S') do
ppBDEPipeline1.SkipBack;

FSkipping := False;

end;

procedure Tfrm0116.ppBDEPipeline1First(Sender: TObject);
begin
SkipForward;
end;

procedure Tfrm0116.ppBDEPipeline1Last(Sender: TObject);
begin
SkipBackward;
end;

procedure Tfrm0116.ppBDEPipeline1Next(Sender: TObject);
begin
SkipForward;
end;

procedure Tfrm0116.ppBDEPipeline1Prior(Sender: TObject);
begin
SkipBackward;
end;

procedure Tfrm0116.ppReport1BeforePrint(Sender: TObject);
begin
FNoData := False;
end;

procedure Tfrm0116.ppReport1HeaderBeforePrint(Sender: TObject);
begin
ppReport1Header.Visible := not(FNoData);
end;

procedure Tfrm0116.ppReport1DetailBeforePrint(Sender: TObject);
begin
ppReport1Detail.Visible := not(FNoData);
end;

procedure Tfrm0116.ppReport1FooterBeforePrint(Sender: TObject);
begin
ppReport1Footer.Visible := not(FNoData);
end;

procedure Tfrm0116.ppReport1GroupFooter1BeforePrint(Sender: TObject);
begin
ppReport1GroupFooter1.Visible := not(FNoData);
end;

procedure Tfrm0116.ppReport1GroupHeader1BeforePrint(Sender: TObject);
begin
ppReport1GroupHeader1.Visible := not(FNoData);
end;

procedure Tfrm0116.ppReport1EndPage(Sender: TObject);
var
lPage: TppPage;
lDrawText: TppDrawText;
begin

if FNoData then
begin
lPage := ppReport1.Engine.Page;

lDrawText := TppDrawText.Create(lPage);
lDrawText.Top := ppReport1.PrinterSetup.PageDef.mmPrintableHeight div
2;
lDrawText.Left := ppReport1.PrinterSetup.PageDef.mmPrintableWidth div
2;
lDrawText.Text := 'NO DATA';
lDrawText.Width := 50800;
lDrawText.Height := 12700;
lDrawText.Font.Color := clBlack;
lDrawText.Font.Size := 18;
lDrawText.Font.Name := 'Arial';
lDrawText.Page := lPage;
end;

end;

end.


Cheers,

Jim Bennett
Digital Metaphors