Dart

Parse MIME Header Fields

See more MIME Examples

Demonstrates how to parse MIME header fields, including Content-Type, Content-Disposition, and Content-Transfer-Encoding.

This example uses a MIME test file located at http://www.chilkatsoft.com/testData/sampleMime2.txt. It contains the following MIME:

Content-Type: multipart/mixed;
 boundary="------------080707010302060306060800";

This is a multi-part message in MIME format.

--------------080707010302060306060800
Content-Type: text/plain
Content-Transfer-Encoding: 7bit

This is the plain-text body.
--------------080707010302060306060800
Content-Disposition: attachment; filename="starfish.gif";
Content-Transfer-Encoding: base64
Content-Type: image/gif; name="starfish.gif";

R0lGODlhIAAgAPcAAP///+/v7/f39+/n5/fv7//39/fn597OzufW1tbGxs69vffe3u/W1salpZQQ
EIQYEJwQCJQYCJwYCM6clL2Ee5wpGIwhEK0YANatpdalnHMYCKUhCJQYAKUYAM6Ec5QhCJwhCPfW
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--------------080707010302060306060800--

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 mime = CkMime();

  // Load the sampleMime2.txt file into the MIME object.
  // (This file is available at http://www.chilkatsoft.com/testData/sampleMime2.txt )

  try {
    mime.loadMimeFile('sampleMime2.txt');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // The GIF image is the 2nd sub-part located directly under the
  // top-level MIME node.  Indexing begins at 0, therefore the 2nd
  // sub-part is at index 1.
  final part2 = CkMime();
  try {
    mime.partAt(1, part2);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // -------------------------------
  // Content-Disposition
  // -------------------------------
  // In this example, the Content-Disposition header field
  // contains this value:
  // attachment; filename="starfish.gif";

  // To get the "filename", call GetHeaderFieldAttribute
  // Header field names and attribute names are case insensitive.
  final filename = part2.getHeaderFieldAttribute('Content-Disposition', 'filename');
  print('Filename: $filename');

  // Because the "filename" is so often accessed, it is also available
  // by accessing the "Filename" property:
  print('Filename: ${part2.filename}');

  // The disposition (without attributes) which in this case 
  // is the string "attachment" is accessed via the Disposition property:
  print('Disposition: ${part2.disposition}');

  // To get the full value of the Content-Disposition header field,
  // call GetHeaderField.
  print('Content-Disposition: ${part2.getHeaderField('Content-Disposition')}');

  // -------------------------------
  // Content-Type
  // -------------------------------
  // In this example, the Content-Type header field
  // contains this value:
  // image/gif; name="starfish.gif";

  // To get the "name", call GetHeaderFieldAttribute
  final name = part2.getHeaderFieldAttribute('Content-Type', 'name');
  print('Content-Type name: $name');

  // Because the "name" is so often accessed, it is also available
  // by accessing the "Name" property:
  print('Content-Type name: ${part2.name}');

  // The content-type without attributes is available in the
  // ContentType property:
  print('Content-Type: ${part2.contentType}');

  // To get the full value of the Content-Type header field,
  // call GetHeaderField.
  print('Content-Type: ${part2.getHeaderField('Content-Type')}');

  // -------------------------------
  // Content-Transfer-Encoding
  // -------------------------------

  // The Encoding property contains the value of the
  // Content-Transfer-Encoding property. 
  // Calling GetHeaderField("Content-Transfer-Encoding") is
  // equivalent to accessing the Encoding property:
  print('Content-Transfer-Encoding: ${part2.encoding}');
  print('Content-Transfer-Encoding: ${part2.getHeaderField('Content-Transfer-Encoding')}');

  print('Finished.');
}