nfcim / ndef

A Dart library to decode & encode NDEF records, supporting multiple types.

ndef

ndef is a Dart library to decode & encode NDEF records, supporting multiple types including (grouped by Type Name Format):

• NFC Well-known Records (TNF 1 / urn:nfc:wkt:), with:
  • Text (class T)
  • URI with well-known prefix (class U)
  • Digital signature (class Sig)
  • Smart poster (class Sp), including sub-record:
    • Action (class act)
    • Size (class s)
    • Type (class t)
  • Connection handover (class Hr/Hs/Hm/Hi/Hc/ac/cr)
• Media Records (TNF 2, containing MIME data), with:
  • Bluetooth easy pairing (class application/vnd.bluetooth.ep.oob)
  • Bluetooth low energy (class application/vnd.bluetooth.le.oob)
• Absolute URI Records (TNF 3)
• External Records (TNF 4 / urn:nfc:ext:), with:
  • Android application record (class android.com:pkg)

This library is still under active development and subject to breaking API changes and malfunction. Pull requests and issues are most welcomed, especially on:

• Bug fixes
• New support for other record types

Usage

import 'package:ndef/ndef.dart' as ndef;

// encoding
var uriRecord = new ndef.UriRecord.fromString("https://github.com/nfcim/ndef");
var textRecord = new ndef.TextRecord(text: "Hello");
var encodedUriRecord = uriRecord.encode().toHexString(); /// encode a single record, and use our extension method on [Uint8List]
var encodedAllRecords = ndef.encodeNdefMessage([uriRecord, textRecord]).toHexString(); // encode several records as a message

// decoding
var encodedTextRecord = "d1010f5402656e48656c6c6f20576f726c6421";
var decodedRecords = ndef.decodeRawNdefMessage(encodedTextRecord.toBytes());
assert(decodedRecords.length == 1);
if (decodedRecords[0] is ndef.TextRecord) {
  assert(decodeRecords[0].text == "Hello");
}  else {
  // we will not reach here
}

// data-binding (by implementing payload as dynamic getter / setter)
var origPayload = uriRecord.payload!;
print(origPayload.toHexString());
uriRecord.content = "github.com/nfcim/flutter_nfc_kit";
print(uriRecord.payload!.toHexString()); // changed
uriRecord.payload = origPayload;
print(uriRecord.content); // changed back

// decoding by providing parts of a record
var partiallyDecodedUrlRecord = ndef.decodePartialNdefMessage(ndef.TypeNameFormat.nfcWellKnown, utf8.encode("U"), origPayload, id: Uint8List.fromList([0x1, 0x2]));

See example code for a more complete example.

Refer to the documentation for detailed usage.