Table component

Next component is TfrxIBXTable. It inherits from TfrxCustomDataSet standard class. All basic functionality (operating with list of fields, master-detail, basic properties) is already realized in basic class. We only need to define properties, which are specific to the given component.

  TfrxIBXTable = class(TfrxCustomTable)
  private
    FDatabase: TfrxIBXDatabase;
    FTable: TIBTable;
    procedure SetDatabase(const Value: TfrxIBXDatabase);
  protected
    procedure Notification(AComponent: TComponent; Operation: TOperation); override;
    procedure SetMaster(const Value: TDataSource); override;
    procedure SetMasterFields(const Value: String); override;
    procedure SetIndexFieldNames(const Value: String); override;
    procedure SetIndexName(const Value: String); override;
    procedure SetTableName(const Value: String); override;
    function GetIndexFieldNames: String; override;
    function GetIndexName: String; override;
    function GetTableName: String; override;
  public
    constructor Create(AOwner: TComponent); override;
    constructor DesignCreate(AOwner: TComponent; Flags: Word); override;
    class function GetDescription: String; override;
    procedure BeforeStartReport; override;
    property Table: TIBTable read FTable;
  published
    property Database: TfrxIBXDatabase read FDatabase write SetDatabase;
  end;

constructor TfrxIBXTable.Create(AOwner: TComponent);
begin
  { create component – table }
  FTable := TIBTable.Create(nil);
  { assign link to  DataSet property from  basic class – do not forget this string! }
  DataSet := FTable;
  { assign link to connection to DB by default }
  SetDatabase(nil);
  { after that basic constructor may be called in}
  inherited;
end;

{ this constructor is called at moment of adding components to report. It connects table to TfrxIBXDatabase component automatically, if it is already present. }
constructor TfrxIBXTable.DesignCreate(AOwner: TComponent; Flags: Word);
var
  i: Integer;
  l: TList;
begin
  inherited;
  l := Report.AllObjects;
  for i := 0 to l.Count - 1 do
    if TObject(l[i]) is TfrxIBXDatabase then
    begin
      SetDatabase(TfrxIBXDatabase(l[i]));
      break;
    end;
end;

class function TfrxIBXTable.GetDescription: String;
begin
  Result := 'IBX Table';
end;

{ trace TfrxIBXDatabase component deleting. We address this component in FDatabase property. Otherwise we can get error. }
procedure TfrxIBXTable.Notification(AComponent: TComponent; Operation: TOperation);
begin
  inherited;
  if (Operation = opRemove) and (AComponent = FDatabase) then
    SetDatabase(nil);
end;

procedure TfrxIBXTable.SetDatabase(const Value: TfrxIBXDatabase);
begin
  {  Database property of TfrxIBXDatabase type, and not of TIBDatabase one! }
  FDatabase := Value;
  { if value <> nil, connect table to selected component }
  if Value <> nil then
    FTable.Database := Value.Database
  { otherwise, try to connect to DB by default, defined in TfrxIBXComponents component }
  else if IBXComponents <> nil then
    FTable.Database := IBXComponents.DefaultDatabase
  { if there were no TfrxIBXComponents for some reason, reset to nil }
  else
    FTable.Database := nil;
  { if connection was a success DBConnected flag should be put }
  DBConnected := FTable.Database <> nil;
end;

function TfrxIBXTable.GetIndexFieldNames: String;
begin
  Result := FTable.IndexFieldNames;
end;

function TfrxIBXTable.GetIndexName: String;
begin
  Result := FTable.IndexName;
end;

function TfrxIBXTable.GetTableName: String;
begin
  Result := FTable.TableName;
end;

procedure TfrxIBXTable.SetIndexFieldNames(const Value: String);
begin
  FTable.IndexFieldNames := Value;
end;

procedure TfrxIBXTable.SetIndexName(const Value: String);
begin
  FTable.IndexName := Value;
end;

procedure TfrxIBXTable.SetTableName(const Value: String);
begin
  FTable.TableName := Value;
end;

procedure TfrxIBXTable.SetMaster(const Value: TDataSource);
begin
  FTable.MasterSource := Value;
end;

procedure TfrxIBXTable.SetMasterFields(const Value: String);
begin
  FTable.MasterFields := Value;
  FTable.IndexFieldNames := Value;
end;

{ we need to implement this method in some cases }
procedure TfrxIBXTable.BeforeStartReport;
begin
  SetDatabase(FDatabase);
end;