hl7v2_mllp 0.1.1

MLLP (Minimum Lower Layer Protocol) transport for HL7v2 messages. TCP client and server with TLS support and automatic reconnection.

example/example.dart

// ignore_for_file: avoid_print, unused_local_variable

import 'package:hl7v2_parser/hl7v2_parser.dart';
import 'package:hl7v2_mllp/hl7v2_mllp.dart';

/// Example showing MLLP client and server usage.
///
/// In a real application, client and server would run in separate processes.
/// This example shows both in one file for illustration.
void main() async {
  // ── Server ───────────────────────────────────────────────────────────
  final server = MllpServer(port: 0); // port 0 = OS-assigned
  await server.start();
  print('Server listening on port ${server.boundPort}');

  // Handle incoming messages
  server.messages.listen((envelope) async {
    final message = Message.parse(envelope.payload);
    print('Server received: ${message.messageType}');

    // Send ACK back
    final ack = message.generateAck(code: AckCode.aa);
    await envelope.respond(ack.encode());
  });

  // ── Client ───────────────────────────────────────────────────────────
  final client = MllpClient(
    host: 'localhost',
    port: server.boundPort,
  );
  await client.connect();

  // Build and send a message
  final order = MessageBuilder()
      .msh((b) => b
          .sendingApplication('APP')
          .sendingFacility('HOSP')
          .receivingApplication('LIS')
          .receivingFacility('LAB')
          .messageType('ORM', 'O01')
          .version('2.5'))
      .addSegment('PID', (b) => b
          .field(3, '12345^^^HOSP^MR')
          .field(5, 'DOE^JOHN'))
      .build();

  final response = await client.send(order.encode());
  final ack = Message.parse(response);
  print('Client received ACK: ${ack.get('MSA-1')}'); // AA

  // ── Cleanup ──────────────────────────────────────────────────────────
  await client.close();
  await server.stop();
  print('Done.');

  // ── TLS example (commented — requires certificates) ──────────────────
  //
  // final tlsConfig = MllpTlsConfig.fromPem(
  //   certChainPath: 'certs/client.pem',
  //   privateKeyPath: 'certs/client.key',
  // );
  //
  // final tlsClient = MllpClient(
  //   host: 'hl7.hospital.org',
  //   port: 2576,
  //   tlsConfig: tlsConfig,
  // );

  // ── Reconnection example (commented) ─────────────────────────────────
  //
  // final reconnectClient = MllpClient(
  //   host: '192.168.1.100',
  //   port: 2575,
  //   reconnectConfig: ReconnectConfig(
  //     initialDelay: Duration(seconds: 1),
  //     maxDelay: Duration(seconds: 30),
  //     maxAttempts: 10,
  //   ),
  // );
  //
  // reconnectClient.reconnectEvents.listen((event) {
  //   print('Reconnect: ${event.type.name}');
  // });
}