(Delphi ActiveX) MIME Content-Disposition Header Field

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

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Integer;
mime: TChilkatMime;

begin
// 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 := TChilkatMime.Create(Self);

// 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"
Memo1.Lines.Add(mime.GetEntireHead());
Memo1.Lines.Add('-');

// 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"
Memo1.Lines.Add(mime.GetEntireHead());
Memo1.Lines.Add('-');

// Notice how the Filename property has been updated
Memo1.Lines.Add('Filename property: ' + mime.Filename);
Memo1.Lines.Add('-');

// To change a particular attribute value, set the property.
mime.Filename := 'skeleton.jpg';
Memo1.Lines.Add(mime.GetEntireHead());
Memo1.Lines.Add('-');

// To remove the filename from the Content-Disposition header,
// set the property to an empty string.
mime.Filename := '';
Memo1.Lines.Add(mime.GetEntireHead());
Memo1.Lines.Add('-');
end;