Dart

Iterate MIME Parts of an Email

See more Email Object Examples

Demonstrates how to iterate over the MIME sub-parts of an email, and retrieve the content of each MIME sub-part body.

Note: This example requires some new features added to Chilkat v9.5.0.95.

Dart

import 'package:chilkat/chilkat.dart';

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

  // See the following Chilkat post to Quickly Understand Email MIME

  final email = CkEmail();

  try {
    email.loadEml('qa_data/eml/sample.eml');
  } on ChilkatException {
    print('Failed to load .eml');
    return;
  }

  final sbContentType = CkStringBuilder();
  final caseSensitive = false;

  // Get the total number of non-multipart MIME sub-parts.
  // (This is a simple way of iterating over all the MIME leaf parts regardless of the MIME tree structure)
  final inlineOnly = false;
  final excludeAttachments = false;
  final searchSpec = '*/*';

  final numParts = email.getNumPartsOfType(searchSpec, inlineOnly, excludeAttachments);
  var i = 0;
  while (i < numParts) {
    // What is the Content-Type of this MIME part?
    sbContentType.append(email.getNthContentType(i, searchSpec, inlineOnly, excludeAttachments));
    if (sbContentType.startsWith('text/', caseSensitive)) {
      // Get the text body of this MIME part.
      final textBody = email.getNthTextPartOfType(i, searchSpec, inlineOnly, excludeAttachments);
      print('Got text body for ${sbContentType.getAsString()}');
    } else {
      if (sbContentType.contentsEqual('message/rfc822', caseSensitive)) {
        // If the Content-Type is message/rfc822, then the MIME body for this part contains a full embedded MIME messages.
        // Your application could load it into a Chilkat email object and recursively process...
        final attachedEmail = CkEmail();
        final bdMime = CkBinData();
        email.getNthBinaryPartOfTypeBd(i, searchSpec, inlineOnly, excludeAttachments, bdMime);
        attachedEmail.setFromMimeBd(bdMime);
        // Now your app can recursively process the attachedEmail...
      } else {
        // Get the bytes of this MIME body part.
        final bd = CkBinData();
        email.getNthBinaryPartOfTypeBd(i, searchSpec, inlineOnly, excludeAttachments, bd);
        print('Got binary body for ${sbContentType.getAsString()} numBytes = ${bd.numBytes}');
      }
    }

    sbContentType.clear();
    i++;
  }
}