Database component

The following component is TfrxIBXDatabase one. It represents a wrapper over TIBDatabase.

  TfrxIBXDatabase = class(TfrxCustomDatabase)
  private
    FDatabase: TIBDatabase;
    FTransaction: TIBTransaction;
    function GetSQLDialect: Integer;
    procedure SetSQLDialect(const Value: Integer);
  protected
    procedure SetConnected(Value: Boolean); override;
    procedure SetDatabaseName(const Value: String); override;
    procedure SetLoginPrompt(Value: Boolean); override;
    procedure SetParams(Value: TStrings); override;
    function GetConnected: Boolean; override;
    function GetDatabaseName: String; override;
    function GetLoginPrompt: Boolean; override;
    function GetParams: TStrings; override;
  public
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
    class function GetDescription: String; override;
    procedure SetLogin(const Login, Password: String); override;
    property Database: TIBDatabase read FDatabase;
  published
    { list TIBDatabase properties. Note – some properties are already exist in base class }
    property DatabaseName;
    property LoginPrompt;
    property Params;
    property SQLDialect: Integer read GetSQLDialect write SetSQLDialect;
    {  Connected property should be placed last! }
    property Connected;
  end;

constructor TfrxIBXDatabase.Create(AOwner: TComponent);
begin
  inherited;
  { create component – connection }
  FDatabase := TIBDatabase.Create(nil);
  { create component - transaction (specificity of  IBX) }
  FTransaction := TIBTransaction.Create(nil);
  FDatabase.DefaultTransaction := FTransaction;
  { do not forget this line! }
  Component := FDatabase;
end;

destructor TfrxIBXDatabase.Destroy;
begin
  { delete  transaction }
  FTransaction.Free;
  { connection will be deleted automatically in parent class }
  inherited;
end;

{ component description will be displayed next to icon in objects toolbar }
class function TfrxIBXDatabase.GetDescription: String;
begin
  Result := 'IBX Database';
end;

{ redirect component properties to  cover properties and vice versa }
function TfrxIBXDatabase.GetConnected: Boolean;
begin
  Result := FDatabase.Connected;
end;

function TfrxIBXDatabase.GetDatabaseName: String;
begin
  Result := FDatabase.DatabaseName;
end;

function TfrxIBXDatabase.GetLoginPrompt: Boolean;
begin
  Result := FDatabase.LoginPrompt;
end;

function TfrxIBXDatabase.GetParams: TStrings;
begin
  Result := FDatabase.Params;
end;

function TfrxIBXDatabase.GetSQLDialect: Integer;
begin
  Result := FDatabase.SQLDialect;
end;

procedure TfrxIBXDatabase.SetConnected(Value: Boolean);
begin
  FDatabase.Connected := Value;
  FTransaction.Active := Value;
end;

procedure TfrxIBXDatabase.SetDatabaseName(const Value: String);
begin
  FDatabase.DatabaseName := Value;
end;

procedure TfrxIBXDatabase.SetLoginPrompt(Value: Boolean);
begin
  FDatabase.LoginPrompt := Value;
end;

procedure TfrxIBXDatabase.SetParams(Value: TStrings);
begin
  FDatabase.Params := Value;
end;

procedure TfrxIBXDatabase.SetSQLDialect(const Value: Integer);
begin
  FDatabase.SQLDialect := Value;
end;

{ this method is used by DB connection wizard }
procedure TfrxIBXDatabase.SetLogin(const Login, Password: String);
begin
  Params.Text := 'user_name=' + Login + #13#10 + 'password=' + Password;
end;

As you can see, this is not that complicated. We create FDatabase: TIBDatabase object, and then define properties we want the designer to have. “Get” and “Set” methods are written for each property.