Pascal (Lazarus/Delphi)

Add, Remove, Update MIME Header Fields

See more MIME Examples

Demonstrates how to add, remove, or update the content of MIME header fields. 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;
  bAllOccurrences: Boolean;
  mpRelated: TMime;
  pJpg: TMime;

begin
  success := False;

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

  mime := TMime.Create;

  //  The contents of this MIME file are shown below, 
  //  and is also available at https://www.chilkatsoft.com/sampleMime.txt
  success := mime.LoadMimeFile('qa_data/mime/sampleMime.txt');
  if (success = False) then
    begin
      WriteLn(mime.LastErrorText);
      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.
  mime.AddHeaderField('hello-world','Hello World!');
  //  If a header field of the same name already exists, the AddHeaderField
  //  method adds a duplicate.
  mime.AddHeaderField('Subject','This is the 2nd Subject header.');
  WriteLn(mime.GetEntireHead());
  WriteLn('-');

  //  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;
  mime.RemoveHeaderField('Subject',bAllOccurrences);
  WriteLn(mime.GetEntireHead());
  WriteLn('-');

  //  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.
  mime.SetHeaderField('hello-world','Goodbye World.');
  WriteLn(mime.GetEntireHead());
  WriteLn('-');

  //  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 := TMime.Create;
  mime.PartAt(1,mpRelated);

  pJpg := TMime.Create;
  mpRelated.PartAt(1,pJpg);

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

  //  View the entire MIME..
  WriteLn(mime.GetMime());

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


  mime.Free;
  mpRelated.Free;
  pJpg.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.