hl7v2_parser 0.1.1

Parse, generate, and access HL7v2 messages in Dart. Lazy parser, typed segment extensions, Terser path access, ACK/NAK generation. Zero dependencies, all platforms.

example/example.dart

// ignore_for_file: avoid_print, unused_local_variable

import 'package:hl7v2_parser/hl7v2_parser.dart';

void main() {
  // ── 1. Parse a message ──────────────────────────────────────────────────
  const raw =
      'MSH|^~\\&|LAB|HOSP|EMR|HOSP|20240101120000||ORU^R01|MSG001|P|2.5\r'
      'PID|||12345^^^HOSP^MR||DOE^JOHN^A||19800101|M\r'
      'OBX|1|NM|WBC^White Blood Cell||7.2|10*3/uL|4.5-11.0|N|||F\r';

  final message = Message.parse(raw);
  print('Type: ${message.messageType}');       // ORU^R01
  print('Version: ${message.version}');        // 2.5
  print('Segments: ${message.segments.length}'); // 3

  // ── 2. Index-based access ───────────────────────────────────────────────
  final pid = message.segment('PID')!;
  final familyName = pid.field(5)?.first.component(0)?.value;
  print('Family name (index): $familyName'); // DOE

  // ── 3. Terser path access ──────────────────────────────────────────────
  final givenName = message.get('PID-5-2');
  print('Given name (Terser): $givenName'); // JOHN

  // Modify in place
  message.set('PID-5-2', 'JANE');
  print('Modified: ${message.get('PID-5-2')}'); // JANE

  // ── 4. Typed segment access ────────────────────────────────────────────
  final typedPid = message.pid!;
  print('Patient name: ${typedPid.patientName}');
  print('Date of birth: ${typedPid.dateOfBirth}');
  print('Sex: ${typedPid.administrativeSex}');

  final obx = message.obx!;
  print('OBX value type: ${obx.valueType}');
  print('OBX observation value: ${obx.observationValue}');

  // ── 5. Generate wire format ────────────────────────────────────────────
  final encoded = message.encode();
  print('Encoded length: ${encoded.length} chars');

  // ── 6. ACK/NAK generation ──────────────────────────────────────────────
  final ack = message.generateAck(code: AckCode.aa);
  print('ACK code: ${ack.get('MSA-1')}');        // AA
  print('ACK control ID: ${ack.get('MSA-2')}');   // MSG001

  final nak = message.generateAck(
    code: AckCode.ar,
    errorMessage: 'Unknown patient',
  );
  print('NAK code: ${nak.get('MSA-1')}'); // AR

  // ── 7. Build a message from scratch ────────────────────────────────────
  final order = MessageBuilder()
      .msh((b) => b
          .sendingApplication('LAB')
          .sendingFacility('HOSP')
          .receivingApplication('EMR')
          .receivingFacility('HOSP')
          .messageType('ORM', 'O01')
          .version('2.5'))
      .addSegment('PID', (b) => b
          .field(3, '12345^^^HOSP^MR')
          .field(5, 'DOE^JOHN^A')
          .field(7, '19800101')
          .field(8, 'M'))
      .addSegment('ORC', (b) => b
          .field(1, 'NW')
          .field(2, 'ORD001'))
      .build();

  print('Built message type: ${order.messageType}'); // ORM^O01

  // ── 8. Structural validation ───────────────────────────────────────────
  final errors = message.validate();
  print('Validation issues: ${errors.length}');
  for (final error in errors) {
    print('  ${error.severity.name}: ${error.message}');
  }
}