Pascal (Lazarus/Delphi)

MIME Content-Disposition Header Field

See more MIME Examples

Explains the Content-Disposition header field and the properties used for setting or updating.

Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.Mime;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  mime: TMime;

begin
  success := False;

  //  The Content-Disposition header field provides a suggestion to the receiver for how the content is to be processed.
  //  The standard dispositions are "inline" and "attachment".  

  //  A disposition of "attachment" indicates the content is something to be saved to a file and not processed (such as rendering for viewing inline).
  //  A disposition of "inline" indicates the content should be processed (displayed) inline with the other parts of the MIME message.

  //  For example, an email client could handle a JPG image based on the disposition.  If the disposition is "attachment",
  //  the email client (such as Thunderbird, GMail, or Outlook) might simply list the JPG image as one of the email's attachments,
  //  but won't display the JPG image.  If the disposition is "inline", the email client might display the JPG image, but not list
  //  it as an attachment.

  //  The Content-Disposition header field can also include a "filename" attribute.  This is the suggested default filename if the content
  //  is to be saved to a file.

  mime := TMime.Create;

  //  The Content-Disposition header field can be set or modified in two ways.
  //  1) By setting the Disposition and Filename properties.

  //  2) By setting the entire contents of the Content-Disposition header with the SetHeaderField method.
  //     Setting the Content-Disposition header automatically updates the Disposition and Filename properties.

  //  For example:
  mime.Disposition := 'attachment';
  mime.Filename := 'ghost.jpg';

  //  The Content-Disposition header field contains this:
  //      Content-Disposition: attachment; filename="ghost.jpg"
  WriteLn(mime.GetEntireHead());
  WriteLn('-');

  //  If we set the entire header field..
  mime.SetHeaderField('Content-Disposition','attachment; filename="zombie.jpg"');
  //  The Content-Disposition header field now contains this:
  //      Content-Disposition: attachment; filename="zombie.jpg"
  WriteLn(mime.GetEntireHead());
  WriteLn('-');

  //  Notice how the Filename property has been updated
  WriteLn('Filename property: ' + mime.Filename);
  WriteLn('-');

  //  To change a particular attribute value, set the property.
  mime.Filename := 'skeleton.jpg';
  WriteLn(mime.GetEntireHead());
  WriteLn('-');

  //  To remove the filename from the Content-Disposition header,
  //  set the property to an empty string.
  mime.Filename := '';
  WriteLn(mime.GetEntireHead());
  WriteLn('-');


  mime.Free;

end;

// ---------------------------------------------------------------------------

begin

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

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.