Delphi DLL

Convert Inline Data-URL Images to Related Parts

Demonstrates the Chilkat Email.ConvertInlineImages method, which converts images embedded inline within HTML (as base64 data URLs) into multipart/related MIME parts referenced from the HTML by cid:. This example sets an HTML body containing a data-URL image and converts it.

Background: HTML can embed an image two ways: as a data: URL (the base64 bytes sit right in the src attribute) or as a related part referenced by cid:. Many email clients don't render data: URLs for security reasons, so converting them to proper multipart/related parts — the traditional email way to embed images — greatly improves how reliably the images display.

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var
success: Boolean;
email: HCkEmail;

begin
success := False;

//  Demonstrates the ConvertInlineImages method, which converts images embedded inline within
//  HTML (as base64 data URLs) into multipart/related MIME parts referenced from the HTML by
//  CID.

email := CkEmail_Create();
CkEmail_putSubject(email,'Convert inline images');

//  An HTML body with a base64 data-URL image (a 1x1 PNG).
CkEmail_SetHtmlBody(email,'<html><body><img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mP8z8BQDwAEhQGAhKmMIQAAAABJRU5ErkJggg=="/></body></html>');

Memo1.Lines.Add('NumRelatedItems before = ' + IntToStr(CkEmail_getNumRelatedItems(email)));

//  Convert the inline data-URL image(s) to multipart/related parts referenced by CID.

success := CkEmail_ConvertInlineImages(email);
if (success = False) then
  begin
    Memo1.Lines.Add(CkEmail__lastErrorText(email));
    Exit;
  end;

Memo1.Lines.Add('NumRelatedItems after = ' + IntToStr(CkEmail_getNumRelatedItems(email)));

CkEmail_Dispose(email);