Intelligent page breaks in reports (Delphi)

Note

This demo is available in your FlexCel installation at <FlexCel Install Folder>\Demo\Delphi\Modules\20.Reports\51.Intelligent Page Breaks In Reports and also at https:​//​github.​com/​tmssoftware/​TMS-​FlexCel.​VCL-​demos/​tree/​master/​Delphi/​Modules/​20.​Reports/​51.​Intelligent Page Breaks In Reports

Overview

Intelligent page breaks are a FlexCel feature that lets you keep together selected rows when printing.

In this demo we will see how to use them on a report.

Make sure to read the conceptual documentation about Intelligent Page Breaks to better understand what we are doing here.

Concepts

• How to create Multi-level "keep together" ranges. In most reports one level is normally enough, but in master detail cases or situations like this one, you might need more than one.

• Take a look at the "keeprows_x_" named ranges in the template. Those are the ranges you use to tell FlexCel which rows to keep together. To have an interesting data sample for our demo, we will write a chart of the customers only if they are from Germany or USA.

• In this example, we want to keep full customers in the same page. But if that isn't possible, we would like the chart not to split in the middle of a page break. That is why we defined a "keeprows_2_" inside "keeprows_1_" protecting the chart. You can see an example of how this works at pages 43-44 when doing a print preview. The chart is completely in a page 44, instead of half in 43 and half in the 44. If you remove the "keeprows_2_" range from the template you will see how that would be otherwise.

Files

UMainForm.pas

unit UMainForm;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics,
  FlexCel.VCLSupport, FlexCel.Core, FlexCel.XlsAdapter, FlexCel.Report, FlexCel.Render,
  {$if CompilerVersion >= 23.0} System.UITypes, {$IFEND}
  ShellApi,
  Controls, Forms, Dialogs, StdCtrls, ExtCtrls;

type
  TMainForm = class(TForm)
    btnCancel: TButton;
    btnGo: TButton;
    SaveDialog: TSaveDialog;
    Label1: TLabel;
    procedure btnCancelClick(Sender: TObject);
    procedure btnGoClick(Sender: TObject);
  private
    procedure RunReport;
    function GetDataPath: string;
    { Private declarations }
  public
    { Public declarations }
  end;

var
  MainForm: TMainForm;

implementation
uses IOUtils, DemoCustomers;

{$R *.dfm}

procedure TMainForm.btnCancelClick(Sender: TObject);
begin
  Close;
end;

procedure TMainForm.btnGoClick(Sender: TObject);
begin
  RunReport;

end;

function TMainForm.GetDataPath: string;
begin
  Result := TPath.Combine(TPath.GetDirectoryName(ParamStr(0)), '..\..');
end;


procedure TMainForm.RunReport;
var
  Report: TFlexCelReport;
begin
  if not SaveDialog.Execute then exit;

  Report := TFlexCelReport.Create(true);
  try
    Report.AddTable(DemoTables);
    Report.SetValue('Date', Now);
    Report.Run(
      TPath.Combine(GetDataPath, 'Intelligent Page Breaks In Reports.template' + TPath.GetExtension(SaveDialog.FileName)),
      SaveDialog.FileName);
  finally
    Report.Free;
  end;

  if MessageDlg('Do you want to open the generated file?', mtConfirmation, [mbYes, mbNo], 0) = mrYes then
  begin
    ShellExecute(0, 'open', PCHAR(SaveDialog.FileName), nil, nil, SW_SHOWNORMAL);
  end;


end;

end.