Pascal (Lazarus/Delphi)

Save an Email to a Temporary MHT File

Demonstrates the Chilkat Email.CreateTempMht method, which prepares the email for display in a web browser and saves it as a temporary MHT file, returning the path that was written. If the filename argument is empty, Chilkat chooses a temporary filename.

To make the message viewable as a standalone web page, the method transforms it: all attachments are dropped; if the email has both HTML and plain-text alternatives, the plain-text alternative is dropped; and if the email has only a plain-text body, it is converted to HTML. This example loads an HTML email and creates the temporary MHT.

Background: MHT (MIME HTML) is a single-file web-page-archive format — it packs an HTML document together with its images and style sheets into one file, which is essentially what an HTML email already is. Because a Windows WebBrowser control can navigate directly to an .mht file, writing the message out as MHT is a quick way to render a received email, inline images and all, inside a desktop application. The transformations (dropping attachments, keeping just the HTML representation) ensure the result is a clean, self-contained page. For unpacking to loose files served by a web application instead, see AspUnpack.

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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.Email;

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

procedure RunDemo;
var
  success: Boolean;
  email: TEmail;
  mhtPath: string;

begin
  success := False;

  //  Demonstrates the CreateTempMht method, which prepares the email for viewing in a browser
  //  and saves it as a temporary MHT (MIME HTML) file, returning the file path.
  //  
  //  To produce browser-viewable output, CreateTempMht transforms the message: it drops all
  //  attachments; if the email has both HTML and plain-text alternatives it drops the
  //  plain-text alternative; and if the email has only a plain-text body it converts that
  //  body to HTML.  Passing an empty filename lets Chilkat choose a temporary filename.

  email := TEmail.Create;

  success := email.LoadEml('qa_data/eml/html_with_images.eml');
  if (success = False) then
    begin
      WriteLn(email.LastErrorText);
      Exit;
    end;

  //  Transform the email for browser display and save it as a temporary MHT file
  //  (empty filename = auto-generated temp file).
  mhtPath := email.CreateTempMht('');

  WriteLn('Temporary MHT file: ' + mhtPath);

  //  Note: The path "qa_data/..." is a relative local filesystem path,
  //  relative to the current working directory of the running application.


  email.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.