TIdHTTPServer with TIdMultiPartFormDataStream

Question

this is related to my previous question here and i found a something that think this might be a solution to my problem but i could not get it to work and i need someone who could help me out.

this is the code
the problem with the code TIdMIMEBoundary.FindBoundary() is undeclared identifier and also the Fetch().

uses
...
IdTCPConnection, IdTCPClient, IdHTTP, IdBaseComponent,
  IdComponent, IdCustomTCPServer, IdCustomHTTPServer, IdHTTPServer,
  IdContext, IdMultipartFormData, IdHeaderList, IdMessageCoder,
  IdMessageCoderMIME, IdMessage, IdGlobalProtocols;


procedure DecodeFormData(const Header: String; ASourceStream:TStream);
var
  MsgEnd: Boolean;
  Decoder: TIdMessageDecoder;
  Tmp: String;
  Dest: TStream;
begin
  MsgEnd := False;
  Decoder := TIdMessageDecoderMIME.Create(nil);
  try
    TIdMessageDecoderMIME(Decoder).MIMEBoundary :=
    TIdMIMEBoundary.FindBoundary(Header);
    Decoder.SourceStream := ASourceStream;
    Decoder.FreeSourceStream := False;
    Decoder.ReadLn;
    repeat
      Decoder.ReadHeader;
      case Decoder.PartType of
        mcptUnknown:
        raise Exception.Create('Unknown form data detected');

        mcptText:
        begin
          Tmp := Decoder.Headers.Values['Content-Type'];
          Dest := TMemoryStream.Create;
          try
            Decoder := Decoder.ReadBody(Dest,MsgEnd);
            if AnsiSameText(Fetch(Tmp, ';'),'multipart/mixed') then
              DecodeFormData(Tmp, Dest)
             else
            // use Dest as needed...
          finally
            FreeAndNil(Dest);
          end;//try
        end;

      mcptAttachment:
      begin
        Tmp := ExtractFileName(Decoder.FileName);
        if Tmp <>'' then
          Tmp := 'c:\some folder\' + Tmp
        else
          Tmp := MakeTempFilename('c:\somefolder\');
        Dest := TFileStream.Create(Tmp, fmCreate);
        try
          Decoder := Decoder.ReadBody(Dest,MsgEnd);
        finally
          FreeAndNil(Dest);
        end;//try
      end;

      end;

      until (Decoder = nil) or MsgEnd;
  finally
    FreeAndNil(Decoder);
  end;//try
end;

Answer 1

You need to include IdMessage and IdMessageCoderMIME in your uses clause

Answer 2

I have created an object called TIdMultiPartFormDataStreamReader that decodes in a single step all the multipart / form-data content that you receive on your server.

unit idMultipartFormDataReader;

interface

{$I IdCompilerDefines.inc}

uses System.SysUtils, System.Classes, IdGlobal, IdGlobalProtocols,
  idMultipartFormData, IdCustomHTTPServer,
  IdCoderQuotedPrintable, IdCoderMIME, IdHeaderList;

type
  TIdMultiPartFormDataStreamReader = class( TIdMultiPartFormDataStream )
  private
    FRequestInfo: TIdHTTPRequestInfo;
  protected
    procedure decodeStream;
  public
    property Fields: TIdFormDataFields read FFields;
    constructor Create( ARequestInfo: TIdHTTPRequestInfo );
  end;

implementation

{ TIdMultiPartFormDataStreamReader }

constructor TIdMultiPartFormDataStreamReader.Create(
  ARequestInfo: TIdHTTPRequestInfo);
begin
  inherited Create;
  FSize := 0;
  FInitialized := False;
  FFields := TIdFormDataFields.Create(Self);
  FRequestInfo := ARequestInfo;
  decodeStream;
end;

procedure TIdMultiPartFormDataStreamReader.decodeStream;
var
  delimi, cadStream: string;
  cabeceras: TIdHeaderList;
  stInfo: TMemoryStream;
  posIniPost, posFinPost, posIniRetorno: Integer;
  cadenaOri: string;
  fieldName: string;
  fieldFileName: string;
  contentType: string;
  charSet: string;
  transferEnconding: string;
  {$IFDEF STRING_IS_ANSI}
    LBytes: TIdBytes;
  {$ENDIF}

  function ReadStringLn( StreamOri: TStream; var cadenaBus: string; char_set: string ): Boolean;
  var
    candidato: Boolean;
    posIniSO: Integer;
    posFinSO: Integer;
    StreamDes: TMemoryStream;
    bleer: Byte;
  begin

    candidato := False;
    StreamDes := TMemoryStream.Create;
    posIniSO := StreamOri.Position;

    cadenaBus := '';

    while ( not candidato ) and ( StreamOri.Position < StreamOri.Size ) do begin

      StreamOri.Read( bleer, 1 );

      if ( bleer = 13 ) then begin

        StreamOri.Read( bleer, 1 );

        if ( bleer = 10 ) then  begin

          candidato := True;
          posFinSO := StreamOri.Position;
          StreamOri.Position := posIniSO;

          if ( posFinSO - 2 - posIniSO > 0 ) then begin

            StreamDes.CopyFrom( StreamOri, posFinSO - 2 - posIniSO );

            StreamDes.Position := 0;

            cadenaBus := IdGlobalProtocols.ReadStringAsCharset( StreamDes, char_set );

          end;

          StreamOri.Position := posFinSO;

        end;

      end;

    end;


    StreamDes.Free;
    Result := candidato;

  end;
begin
  {$IFDEF STRING_IS_ANSI}
  LBytes := nil;
  {$ENDIF}

  if ( ExtractHeaderItem( FRequestInfo.RawHeaders.Values[ 'Content-Type' ] ) <> 'multipart/form-data' ) then
    Exit;

  cabeceras := TIdHeaderList.Create( TIdHeaderQuotingType.QuoteHTTP );

  delimi := FRequestInfo.RawHeaders.Params['Content-Type', 'boundary'];

  FBoundary := delimi;

  FRequestContentType := sContentTypeFormData + FBoundary;

  FRequestInfo.PostStream.Position := 0;

  if ( ReadStringLn( FRequestInfo.PostStream, cadenaOri, FRequestInfo.CharSet ) ) then begin

    while ( cadenaOri = '--' + delimi )  and
          ( FRequestInfo.PostStream.Position < FRequestInfo.PostStream.Size ) do begin

      if ( ReadStringLn( FRequestInfo.PostStream, cadenaOri, FRequestInfo.CharSet ) ) then begin

        while ( cadenaOri <> '' ) and
          ( FRequestInfo.PostStream.Position < FRequestInfo.PostStream.Size ) do begin

          cabeceras.Add( cadenaOri );
          ReadStringLn( FRequestInfo.PostStream, cadenaOri, FRequestInfo.CharSet );

        end;

        fieldName := cabeceras.Params[ 'Content-Disposition', 'name' ];
        fieldFileName := cabeceras.Params[ 'Content-Disposition', 'filename' ];


        contentType := ExtractHeaderItem( cabeceras.Values[ 'Content-Type' ] );
        charSet := cabeceras.Params[ 'Content-Type', 'charset' ];

        transferEnconding := cabeceras.Values[ 'Content-Transfer-Encoding' ];

        stInfo := TMemoryStream.Create;
        posIniPost := FRequestInfo.PostStream.Position;
        posFinPost := posIniPost;

        ReadStringLn( FRequestInfo.PostStream, cadenaOri, FRequestInfo.CharSet );

        while ( cadenaOri <> '--' + delimi ) and ( cadenaOri <> '--' + delimi + '--' )  and
          ( FRequestInfo.PostStream.Position < FRequestInfo.PostStream.Size ) do begin

          posFinPost := FRequestInfo.PostStream.Position;
          ReadStringLn( FRequestInfo.PostStream, cadenaOri, FRequestInfo.CharSet );

        end;

        posIniRetorno := FRequestInfo.PostStream.Position;

        FRequestInfo.PostStream.Position := posIniPost;

        if ( posFinPost - 2 - posIniPost > 0 ) then begin

          if ( fieldFileName <> '' ) then begin

            stInfo.CopyFrom( FRequestInfo.PostStream, posFinPost - 2 - posIniPost );

            if ( LowerCase( transferEnconding ) = 'quoted-printable' ) then begin

              stInfo.Position := 0;

              cadStream := ReadStringFromStream( stInfo );

              stInfo.Clear;
              stInfo.Position := 0;

              TIdDecoderQuotedPrintable.DecodeStream( cadStream, stInfo );

            end else if ( LowerCase( transferEnconding ) = 'base64' ) then begin

              stInfo.Position := 0;

              cadStream := ReadStringFromStream( stInfo );

              stInfo.Clear;
              stInfo.Position := 0;

              TIdDecoderMIME.DecodeStream( cadStream, stInfo );

            end;

            stInfo.Position := 0;

            AddFormField( fieldName, contentType, charSet, stInfo, fieldFileName );

          end else begin

            stInfo.CopyFrom( FRequestInfo.PostStream, posFinPost - 2 - posIniPost );

            cadStream := '';

            stInfo.Position := 0;

            {$IFDEF STRING_IS_ANSI}

            ReadTIdBytesFromStream( stInfo, LBytes, stInfo.Size );

            {$ENDIF}

            if ( LowerCase( transferEnconding ) = '7bit' ) then begin

              {$IFDEF STRING_IS_UNICODE}

              cadStream := ReadStringFromStream( stInfo, -1, IndyTextEncoding_ASCII );

              {$ELSE}

              CheckByteEncoding( LBytes, IndyTextEncoding_ASCII, CharsetToEncoding( charSet ) );

              {$ENDIF}

            end else if ( LowerCase( transferEnconding ) = 'quoted-printable' ) then begin

              {$IFDEF STRING_IS_UNICODE}

              cadStream := ReadStringFromStream( stInfo );

              cadStream := TIdDecoderQuotedPrintable.DecodeString( cadStream, CharsetToEncoding( charSet ) );

              {$ELSE}

              BytesToRaw( LBytes, cadStream, Length( LBytes ) );

              LBytes := TIdDecoderQuotedPrintable.DecodeBytes( cadStream );

              {$ENDIF}

            end else if ( LowerCase( transferEnconding ) = 'base64' ) then begin

              {$IFDEF STRING_IS_UNICODE}

              cadStream := ReadStringFromStream( stInfo );

              cadStream := TIdDecoderMIME.DecodeString( cadStream, CharsetToEncoding( charSet ) );

              {$ELSE}

              BytesToRaw( LBytes, cadStream, Length( LBytes ) );

              LBytes := TIdDecoderMIME.DecodeBytes( cadStream );

              {$ENDIF}

            end else if ( LowerCase( transferEnconding ) = '8bit' ) or ( LowerCase( transferEnconding ) = 'binary' ) then begin

              {$IFDEF STRING_IS_UNICODE}

              cadStream := ReadStringAsCharset( stInfo, charSet );

              {$ENDIF}

            end;

            {$IFDEF STRING_IS_ANSI}

            BytesToRaw( LBytes, cadStream, Length( LBytes ) );

            {$ENDIF}

            AddFormField( fieldName, cadStream, charSet, contentType );

            stInfo.Free;

          end;

        end;

        FRequestInfo.PostStream.Position := posIniRetorno;

        cabeceras.Clear;

      end;

    end;

  end;

end;

end.

the project is in https://github.com/enriquecerda/TIdMultiPartFormDataStreamReader