FastReport Example: Display data in TfrxReport from Business Object using TfrxUserDataSet

Unit1.dfm

object Form1: TForm1
  Left = 0
  Top = 0
  Caption = 'Form1'
  ClientHeight = 242
  ClientWidth = 472
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'Tahoma'
  Font.Style = []
  OldCreateOrder = False
  OnCreate = FormCreate
  OnShow = FormShow
  PixelsPerInch = 96
  TextHeight = 13
  object frxReport1: TfrxReport
    Version = '5.6.1'
    DotMatrixReport = False
    IniFile = '\Software\Fast Reports'
    PreviewOptions.Buttons = [pbPrint, pbLoad, pbSave, pbExport, pbZoom, pbFind, pbOutline, pbPageSetup, pbTools, pbEdit, pbNavigator, pbExportQuick]
    PreviewOptions.Zoom = 1.000000000000000000
    PrintOptions.Printer = 'Padr'#227'o'
    PrintOptions.PrintOnSheet = 0
    ReportOptions.CreateDate = 43354.359786655090000000
    ReportOptions.LastChange = 43354.359786655090000000
    ScriptLanguage = 'PascalScript'
    ScriptText.Strings = (
      'begin'
      ''
      'end.')
    Left = 216
    Top = 24
    Datasets = <
      item
        DataSet = DSCars
        DataSetName = 'DSCars'
      end
      item
        DataSet = DSPerson
        DataSetName = 'DSPerson'
      end
      item
        DataSet = DSPets
        DataSetName = 'DSPets'
      end>
    Variables = <>
    Style = <>
    object Data: TfrxDataPage
      Height = 1000.000000000000000000
      Width = 1000.000000000000000000
    end
    object Page1: TfrxReportPage
      PaperWidth = 210.000000000000000000
      PaperHeight = 297.000000000000000000
      PaperSize = 9
      LeftMargin = 10.000000000000000000
      RightMargin = 10.000000000000000000
      TopMargin = 10.000000000000000000
      BottomMargin = 10.000000000000000000
      object MasterData1: TfrxMasterData
        FillType = ftBrush
        Height = 22.677180000000000000
        Top = 18.897650000000000000
        Width = 718.110700000000000000
        DataSet = DSPerson
        DataSetName = 'DSPerson'
        RowCount = 1
        object DSPessoaId: TfrxMemoView
          Left = 3.779530000000000000
          Width = 128.504020000000000000
          Height = 18.897650000000000000
          DataField = 'Id'
          DataSet = DSPerson
          DataSetName = 'DSPerson'
          Font.Charset = DEFAULT_CHARSET
          Font.Color = clWindowText
          Font.Height = -13
          Font.Name = 'Arial'
          Font.Style = []
          Memo.UTF8W = (
            '[DSPerson."Id"]')
          ParentFont = False
        end
        object DSPessoaNome: TfrxMemoView
          Left = 136.063080000000000000
          Width = 294.803340000000000000
          Height = 18.897650000000000000
          DataSet = DSPerson
          DataSetName = 'DSPerson'
          Font.Charset = DEFAULT_CHARSET
          Font.Color = clWindowText
          Font.Height = -13
          Font.Name = 'Arial'
          Font.Style = []
          Memo.UTF8W = (
            '[DSPerson."Name"]')
          ParentFont = False
        end
      end
      object DetailData1: TfrxDetailData
        FillType = ftBrush
        Height = 22.677180000000000000
        Top = 64.252010000000000000
        Width = 718.110700000000000000
        DataSet = DSCars
        DataSetName = 'DSCars'
        RowCount = 0
        object DSCarsId: TfrxMemoView
          Left = 45.354360000000000000
          Width = 79.370130000000000000
          Height = 18.897650000000000000
          DataField = 'Id'
          DataSet = DSCars
          DataSetName = 'DSCars'
          Font.Charset = DEFAULT_CHARSET
          Font.Color = clWindowText
          Font.Height = -13
          Font.Name = 'Arial'
          Font.Style = []
          Memo.UTF8W = (
            '[DSCars."Id"]')
          ParentFont = False
        end
        object DSCarsModelo: TfrxMemoView
          Left = 132.283550000000000000
          Width = 294.803340000000000000
          Height = 18.897650000000000000
          DataSet = DSCars
          DataSetName = 'DSCars'
          Font.Charset = DEFAULT_CHARSET
          Font.Color = clWindowText
          Font.Height = -13
          Font.Name = 'Arial'
          Font.Style = []
          Memo.UTF8W = (
            '[DSCars."Model"]')
          ParentFont = False
        end
      end
      object DetailData2: TfrxDetailData
        FillType = ftBrush
        Height = 22.677180000000000000
        Top = 109.606370000000000000
        Width = 718.110700000000000000
        DataSet = DSPets
        DataSetName = 'DSPets'
        RowCount = 0
        object DSPetsId: TfrxMemoView
          Left = 45.354360000000000000
          Width = 79.370130000000000000
          Height = 18.897650000000000000
          DataField = 'Id'
          DataSet = DSPets
          DataSetName = 'DSPets'
          Font.Charset = DEFAULT_CHARSET
          Font.Color = clWindowText
          Font.Height = -13
          Font.Name = 'Arial'
          Font.Style = []
          Memo.UTF8W = (
            '[DSPets."Id"]')
          ParentFont = False
        end
        object Memo1: TfrxMemoView
          Left = 132.283550000000000000
          Width = 294.803340000000000000
          Height = 18.897650000000000000
          DataSet = DSPets
          DataSetName = 'DSPets'
          Font.Charset = DEFAULT_CHARSET
          Font.Color = clWindowText
          Font.Height = -13
          Font.Name = 'Arial'
          Font.Style = []
          Memo.UTF8W = (
            '[DSPets."Breed"]')
          ParentFont = False
        end
      end
    end
  end
  object DSPerson: TfrxUserDataSet
    UserName = 'DSPerson'
    Fields.Strings = (
      'Id'
      'Name')
    OnGetValue = DSPersonGetValue
    Left = 216
    Top = 80
  end
  object DSCars: TfrxUserDataSet
    UserName = 'DSCars'
    Fields.Strings = (
      'Id'
      'Model')
    OnGetValue = DSCarsGetValue
    Left = 168
    Top = 136
  end
  object DSPets: TfrxUserDataSet
    UserName = 'DSPets'
    Fields.Strings = (
      'Id'
      'Breed')
    OnGetValue = DSPetsGetValue
    Left = 248
    Top = 136
  end
end

Unit1.pas

unit Unit1;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, system.generics.collections, frxClass;

type
  TCar = class
  public
    FId: Integer;
    FModel: String;
  end;

  TPet = class
  public
    FId: Integer;
    FBreed: String;
  end;

  TPerson = class
  public
    FId: Integer;
    FNome: String;
    FCars: TList<TCar>;
    FPets: TList<TPet>;
    constructor Create;
  end;

  TForm1 = class(TForm)
    frxReport1: TfrxReport;
    DSPerson: TfrxUserDataSet;
    DSCars: TfrxUserDataSet;
    DSPets: TfrxUserDataSet;
    procedure FormCreate(Sender: TObject);
    procedure DSPersonGetValue(const VarName: string; var Value: Variant);
    procedure FormShow(Sender: TObject);
    procedure DSCarsGetValue(const VarName: string; var Value: Variant);
    procedure DSPetsGetValue(const VarName: string; var Value: Variant);
  private
    FPerson: TPerson;
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

{ TPessoa }

constructor TPerson.Create;
begin
  FCars := TList<TCar>.Create;
  FPets := TList<TPet>.Create;
end;

procedure TForm1.DSCarsGetValue(const VarName: string; var Value: Variant);
begin
  if (VarName = 'Id') then
    Value := FPerson.FCars[DSCars.RecNo].FId;
  if (VarName = 'Model') then
    Value := FPerson.FCars[DSCars.RecNo].FModel;
end;

procedure TForm1.DSPersonGetValue(const VarName: string; var Value: Variant);
begin
  if (VarName = 'Id') then
    Value := FPerson.FId;
  if (VarName = 'Name') then
    Value := FPerson.FNome;
end;

procedure TForm1.DSPetsGetValue(const VarName: string; var Value: Variant);
begin
  if (VarName = 'Id') then
    Value := FPerson.FPets[DSPets.RecNo].FId;
  if (VarName = 'Breed') then
    Value := FPerson.FPets[DSPets.RecNo].FBreed;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  FPerson := TPerson.Create;

  FPerson.FId := 1;
  FPerson.FNome := 'Person Name';

  FPerson.FCars.Add(TCar.Create);
  FPerson.FCars.Add(TCar.Create);
  FPerson.FCars[0].FId := 1;
  FPerson.FCars[0].FModel := 'Honda Civic';
  FPerson.FCars[1].FId := 2;
  FPerson.FCars[1].FModel := 'BMW E320';

  FPerson.FPets.Add(TPet.Create);
  FPerson.FPets.Add(TPet.Create);
  FPerson.FPets[0].FId := 1;
  FPerson.FPets[0].FBreed := 'Samoieda';
  FPerson.FPets[1].FId := 2;
  FPerson.FPets[1].FBreed := 'Pastor Alemão';

  DSPerson.RangeEnd := reCurrent;

  DSCars.RangeEnd := reCount;
  DSPets.RangeEnd := reCount;

  DSCars.RangeEndCount := FPerson.FCars.Count;
  DSPets.RangeEndCount := FPerson.FPets.Count;
end;

procedure TForm1.FormShow(Sender: TObject);
begin
  frxReport1.ShowReport;
end;

end.