statt x-fache „if then else“-Abfragen eine intelligentere Lösung gesucht

[Sir Rufo]

Baue dir doch einen Builder, der eben diese Dateinamen erstellt.

Die gewünschten Teile (Interpret, Titel, ...) und deren Reihenfolge einfach dem Builder übergeben und dann damit durch die Dateien laufen.
Für Vorbelegungen (Radiogroup) kannst du pro Eintrag eine Builder-Instanz hinterlegen und diese dann benutzen.

Delphi-Quellcode:

unit FilenameBuilder;

interface

uses
  Classes,
  Generics.Collections,
  SysUtils;

type
  TMP3Meta = record
    Interpret : string;
    Titel : string;
    Album : string;
    CdNr : Integer;
    TrackNr : Integer;
  end;

  IFilenamePart = interface
    ['{281FA130-B641-454D-8E9A-58D0C02F4C14}']
    function Build( const AData : TMP3Meta ) : string;
  end;

  TFilenamePartFactory = class
  private
    FParts : TDictionary<string, IFilenamePart>;
  public
    constructor Create;
    destructor Destroy; override;

    function GetPart( const AKey : string ) : IFilenamePart;
  end;

  TFilenameBuilder = class
  private
    FParts : TList<IFilenamePart>;
  public
    constructor Create;
    destructor Destroy; override;

    procedure AddPart( APart : IFilenamePart );
    procedure Clear;

    function GetFilename( const AData : TMP3Meta ) : string;
  end;

implementation

type
  TFilenamePart = class( TInterfacedObject, IFilenamePart )
  protected
    function Build( const AData : TMP3Meta ) : string; virtual; abstract;
  end;

  TInterpretPart = class( TFilenamePart )
  protected
    function Build( const AData : TMP3Meta ) : string; override;
  end;

  TTitelPart = class( TFilenamePart )
  protected
    function Build( const AData : TMP3Meta ) : string; override;
  end;

  TAlbumPart = class( TFilenamePart )
  protected
    function Build( const AData : TMP3Meta ) : string; override;
  end;

  TCdNrPart = class( TFilenamePart )
  protected
    function Build( const AData : TMP3Meta ) : string; override;
  end;

  TTrackNrPart = class( TFilenamePart )
  protected
    function Build( const AData : TMP3Meta ) : string; override;
  end;

  { TFilenameBuilder }

procedure TFilenameBuilder.AddPart( APart : IFilenamePart );
begin
  FParts.Add( APart );
end;

procedure TFilenameBuilder.Clear;
begin
  FParts.Clear;
end;

constructor TFilenameBuilder.Create;
begin
  inherited Create;
  FParts := TList<IFilenamePart>.Create;
end;

destructor TFilenameBuilder.Destroy;
begin
  FParts.Free;
  inherited;
end;

function TFilenameBuilder.GetFilename( const AData : TMP3Meta ) : string;
var
  LBuilder : TStringBuilder;
  LIdx :     Integer;
begin
  LBuilder := TStringBuilder.Create;
  try
    for LIdx := 0 to FParts.Count - 1 do
      begin
        if LIdx > 0
        then
          LBuilder.Append( '-' );

        LBuilder.Append( FParts[LIdx].Build( AData ) );
      end;

    Result := LBuilder.ToString;

  finally
    LBuilder.Free;
  end;
end;

{ TInterpretPart }

function TInterpretPart.Build( const AData : TMP3Meta ) : string;
begin
  Result := AData.Interpret;
end;

{ TTitelPart }

function TTitelPart.Build( const AData : TMP3Meta ) : string;
begin
  Result := AData.Titel;
end;

{ TAlbumPart }

function TAlbumPart.Build( const AData : TMP3Meta ) : string;
begin
  Result := AData.Album;
end;

{ TCdNrPart }

function TCdNrPart.Build( const AData : TMP3Meta ) : string;
begin
  Result := IntToStr( AData.CdNr );
end;

{ TTrackNrPart }

function TTrackNrPart.Build( const AData : TMP3Meta ) : string;
begin
  Result := IntToStr( AData.TrackNr );
end;

{ TFilenamePartFactory }

constructor TFilenamePartFactory.Create;
begin
  inherited Create;
  FParts := TDictionary<string, IFilenamePart>.Create;

  FParts.Add( 'Interpret', TInterpretPart.Create );
  FParts.Add( 'Titel', TTitelPart.Create );
  FParts.Add( 'Album', TAlbumPart.Create );
  FParts.Add( 'CdNr', TCdNrPart.Create );
  FParts.Add( 'TrackNr', TTrackNrPart.Create );
end;

destructor TFilenamePartFactory.Destroy;
begin
  FParts.Free;
  inherited;
end;

function TFilenamePartFactory.GetPart( const AKey : string ) : IFilenamePart;
begin
  Result := FParts[AKey];
end;

end.

Das sieht zwar wild aus, ist aber in der Anwendung relativ zahm

Delphi-Quellcode:

program FilenameBuilderTest;

{$APPTYPE CONSOLE}
{$R *.res}

uses
  System.SysUtils,
  FilenameBuilder in 'FilenameBuilder.pas';

var
  PartFactory : TFilenamePartFactory;

procedure Test;
var
  LFilenameBuilder : TFilenameBuilder;
  LData :            TMP3Meta;
begin

  LData.Interpret := 'Testinterpret';
  LData.Titel     := 'Testtitel';
  LData.Album     := 'TestAlbum';
  LData.CdNr      := 1;
  LData.TrackNr   := 10;

  LFilenameBuilder := TFilenameBuilder.Create;
  try

    LFilenameBuilder.AddPart( PartFactory.GetPart( 'TrackNr' ) );
    LFilenameBuilder.AddPart( PartFactory.GetPart( 'CdNr' ) );
    LFilenameBuilder.AddPart( PartFactory.GetPart( 'Album' ) );
    LFilenameBuilder.AddPart( PartFactory.GetPart( 'Interpret' ) );
    LFilenameBuilder.AddPart( PartFactory.GetPart( 'Titel' ) );

    WriteLn( LFilenameBuilder.GetFilename( LData ) );

    LFilenameBuilder.Clear;

    LFilenameBuilder.AddPart( PartFactory.GetPart( 'CdNr' ) );
    LFilenameBuilder.AddPart( PartFactory.GetPart( 'TrackNr' ) );
    LFilenameBuilder.AddPart( PartFactory.GetPart( 'Interpret' ) );
    LFilenameBuilder.AddPart( PartFactory.GetPart( 'Titel' ) );

    WriteLn( LFilenameBuilder.GetFilename( LData ) );

  finally
    LFilenameBuilder.Free;
  end;

end;

begin
  try

    PartFactory := TFilenamePartFactory.Create;
    try

      Test;

    finally
      PartFactory.Free;
    end;

  except
    on E : Exception do
      WriteLn( E.ClassName, ': ', E.Message );
  end;

  ReadLn;

end.