Dart

Check if a MIME Entity is multipart/alternative

Demonstrates the Chilkat Mime.IsMultipartAlternative method, which returns whether the Content-Type is exactly multipart/alternative. It takes no arguments.

Note: The file path is relative to the application's current working directory. Absolute paths may also be used. Supply the path to your own file.

Background: Recognizing multipart/alternative matters because its children are the same content in different formats — you display one (usually the last renderable), not all of them. That is the opposite of multipart/mixed, where every child is shown.

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Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // Demonstrates the Mime.IsMultipartAlternative method, which returns whether the Content-Type is multipart/alternative.  It takes no arguments.

  final mime = CkMime();
  try {
    mime.loadMimeFile('qa_data/multipart_message.eml');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  if (mime.isMultipartAlternative()) {
    print('This is a multipart/alternative entity.');
  } else {
    print('This is not multipart/alternative.');
  }
}