(Delphi DLL) Add, Remove, Update MIME Header Fields

Demonstrates how to add, remove, or update the content of MIME header fields.

Note: This example requires Chilkat v11.0.0 or greater.

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

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
mime: HCkMime;
bAllOccurrences: Boolean;
mpRelated: HCkMime;
pJpg: HCkMime;

begin
success := False;

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

mime := CkMime_Create();

// The contents of this MIME file are shown below, 
// and is also available at https://www.chilkatsoft.com/sampleMime.txt
success := CkMime_LoadMimeFile(mime,'qa_data/mime/sampleMime.txt');
if (success = False) then
  begin
    Memo1.Lines.Add(CkMime__lastErrorText(mime));
    Exit;
  end;

// The MIME used in this example has the following nested structure
// 
// multipart/alternative
//     text/plain
//     multipart/related
//         text/html
//         image/jpeg
// 

// Adding a top-level MIME header is easy.
CkMime_AddHeaderField(mime,'hello-world','Hello World!');
// If a header field of the same name already exists, the AddHeaderField
// method adds a duplicate.
CkMime_AddHeaderField(mime,'Subject','This is the 2nd Subject header.');
Memo1.Lines.Add(CkMime__getEntireHead(mime));
Memo1.Lines.Add('-');

// The top-level header now looks like this:
// 
// 	Subject: Test email.
// 	Content-Type: multipart/alternative; boundary="------------DB171738719FB06D67DEBAA0"
// 	MIME-Version: 1.0
// 	hello-world: Hello World!
// 	Subject: This is the 2nd Subject header.
// 

// The RemoveHeaderField method can remove the 1st occurrance, or all occurrences.
bAllOccurrences := True;
// Remove all occurrences of the Subject header;
CkMime_RemoveHeaderField(mime,'Subject',bAllOccurrences);
Memo1.Lines.Add(CkMime__getEntireHead(mime));
Memo1.Lines.Add('-');

// After removing all Subject header fields, the top-level header now looks like this:
// 
// Content-Type: multipart/alternative; boundary="------------DB171738719FB06D67DEBAA0"
// MIME-Version: 1.0
// hello-world: Hello World!
// 

// The content of a header field can be updated by calling SetHeaderField.
// If the header field does not already exist, it is added.  Otherwise it is updated.
// Note: The order of header fields SHOULD never matter.
CkMime_SetHeaderField(mime,'hello-world','Goodbye World.');
Memo1.Lines.Add(CkMime__getEntireHead(mime));
Memo1.Lines.Add('-');

// Now we have:
// 
// 	Content-Type: multipart/alternative; boundary="------------DB171738719FB06D67DEBAA0"
// 	MIME-Version: 1.0
// 	hello-world: Goodbye World.
// 

// To add/update/delete header fields in sub-parts, navigate to
// the sub-part and do the same..

mpRelated := CkMime_Create();
CkMime_PartAt(mime,1,mpRelated);

pJpg := CkMime_Create();
CkMime_PartAt(mpRelated,1,pJpg);

// Add a header to the image/jpeg sub-header.
CkMime_SetHeaderField(pJpg,'CustomHeader','This is the custom header value.');

// View the entire MIME..
Memo1.Lines.Add(CkMime__getMime(mime));

// --------------------------------------------------------------
// --------------------------------------------------------------
// The MIME sample file loaded at the beginning of this example
// contains the following MIME:

// Subject: Test email.
// Content-Type: multipart/alternative;
// 	boundary="------------DB171738719FB06D67DEBAA0"
// MIME-Version: 1.0
// 
// --------------DB171738719FB06D67DEBAA0
// Content-Type: text/plain; charset="utf-8"; format=flowed
// Content-Transfer-Encoding: 7bit
// 
// This is a test.
// 
// --------------DB171738719FB06D67DEBAA0
// Content-Type: multipart/related;
// 	boundary="------------A940F1230E6F0105F03DB2CB"
// 
// --------------A940F1230E6F0105F03DB2CB
// Content-Type: text/html; charset="utf-8"
// Content-Transfer-Encoding: 8bit
// 
// <html><head>
// <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
//   </head>
//   <body bgcolor="#FFFFFF" text="#000000">
//     <p>This is a test.&nbsp; <img src="cid:part1.E16AE3B4.1505C436@chilkatsoft.com" height="20" width="20"></p>
//   </body>
// </html>
// 
// --------------A940F1230E6F0105F03DB2CB
// Content-Type: image/jpeg; name="starfish20.jpg"
// Content-Transfer-Encoding: base64
// Content-ID: <part1.E16AE3B4.1505C436@chilkatsoft.com>
// Content-Disposition: inline; filename="starfish20.jpg"
// 
// /9j/4AAQSkZJRgABAQEASABIAAD//gAmRmlsZSB3cml0dGVuIGJ5IEFkb2JlIFBob3Rvc2hvcD8g
// NC4w/9sAQwAQCwwODAoQDg0OEhEQExgoGhgWFhgxIyUdKDozPTw5Mzg3QEhcTkBEV0U3OFBtUVdf
// YmdoZz5NcXlwZHhcZWdj/9sAQwEREhIYFRgvGhovY0I4QmNjY2NjY2NjY2NjY2NjY2NjY2NjY2Nj
// Y2NjY2NjY2NjY2NjY2NjY2NjY2NjY2NjY2Nj/8IAEQgAFAAUAwERAAIRAQMRAf/EABcAAAMBAAAA
// AAAAAAAAAAAAAAIDBAX/xAAYAQADAQEAAAAAAAAAAAAAAAABAgMEAP/aAAwDAQACEAMQAAAB2kZY
// NNEijWKddfTmLgALWH//xAAbEAACAgMBAAAAAAAAAAAAAAABAgMRAAQSE//aAAgBAQABBQL0XqN+
// pM2aqJGMiqFFCyg7z//EABwRAAICAgMAAAAAAAAAAAAAAAERAAIQIQMSUf/aAAgBAwEBPwHqU5aq
// Axx+y1tMQl4elj//xAAcEQEAAQUBAQAAAAAAAAAAAAABEQACEBIhA1H/2gAIAQIBAT8B3Bhqy7Zc
// enyiwmGgDhiOzj//xAAdEAABAwUBAAAAAAAAAAAAAAABAAIREBIhIkFR/9oACAEBAAY/ArZyn+Cg
// xtxWuJaoCnqDuin/xAAcEAABBAMBAAAAAAAAAAAAAAABABEhYRAxQVH/2gAIAQEAAT8hkEwPUUR9
// DYfE4nxtRpIkBTsayuALIiuY/9oADAMBAAIAAwAAABDWPTsf/8QAGhEAAwADAQAAAAAAAAAAAAAA
// AAEREDFBIf/aAAgBAwEBPxC0DVPcWm+Ce4OesrkE6bjH/8QAGBEBAQEBAQAAAAAAAAAAAAAAAREA
// QRD/2gAIAQIBAT8QahMiOc8YgSrnTY3ELclHXn//xAAcEAEBAAIDAQEAAAAAAAAAAAABEQAhMUFx
// EFH/2gAIAQEAAT8Qn3igmSZSj+c4N4zapMy9IjFV98wncN2iuLFsCEbDGxQkI6RO/n//2Q==
// 
// --------------A940F1230E6F0105F03DB2CB--
// 
// --------------DB171738719FB06D67DEBAA0--
// 

CkMime_Dispose(mime);
CkMime_Dispose(mpRelated);
CkMime_Dispose(pJpg);

end;