Dart
Add Image to HTML Email

Demonstrates how to add an image to an HTML email.
Chilkat Dart Downloads

Dart
import 'package:chilkat/chilkat.dart';

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

  final email = CkEmail();

  email.from = 'Matt <matt@example.com>';
  email.addTo('Joe', 'joe@example.com');
  email.subject = 'This is a test';

  // Add an HTML body with an image tag.
  final html = '<html><body><p>Test with image:</p><p><img src="/wildlife/starfish.jpg" /></p></body></html>';
  email.setHtmlBody(html);

  // Add the image data from a file.  The pathInHtml must match the value of the img tag's src attribute.
  final pathInHtml = '/wildlife/starfish.jpg';
  // The actual path of the JPG file in the local filesystem:
  final pathOnDisk = 'qa_data/jpg/starfish20.jpg';

  try {
    email.addRelatedFile2(pathOnDisk, pathInHtml);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // The email is now properly constructed with an image that will be visible in the HTML.
  // In this example, we'll save it to a .eml file and verify by loading the .eml in an email client such as Mozilla Thunderbird.

  email.saveEml('qa_output/starfish.eml');

  // Also, we can examine the MIME to understand how the image data in the MIME is associated with the img tag in the HTML.
  // It is the Content-Location header value that must match the value of the img tag's src attribute.

  print(email.getMime());

  // Here's the MIME:

  // MIME-Version: 1.0
  // Date: Thu, 26 May 2022 11:09:12 -0500
  // Message-ID: <B1D499F74F533E287BFE04BBD79AAF1D973B61E3@SLICE>
  // Content-Type: multipart/related; boundary="------------000205040704010904010706"
  // X-Priority: 3 (Normal)
  // From: Matt <matt@example.com>
  // To: Joe <joe@example.com>
  // Subject: This is a test
  // 
  // --------------000205040704010904010706
  // Content-Type: text/html; charset=us-ascii
  // Content-Transfer-Encoding: 7bit
  // 
  // <html><body><p>Test with image:</p><p><img src="/wildlife/starfish.jpg" /></p></body></html>
  // --------------000205040704010904010706
  // Content-Type: image/jpeg; name="/wildlife/starfish.jpg"
  // Content-Transfer-Encoding: base64
  // Content-Disposition: inline; filename="/wildlife/starfish.jpg"
  // Content-Location: /wildlife/starfish.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==
  // 
  // --------------000205040704010904010706--
}