dartrosa

A pure-Dart ODK XForms engine: a faithful port of JavaRosa 6.0.0, the engine behind ODK Collect. It parses XForms, evaluates XPath, recalculates, validates, handles repeats, secondary instances and translations, navigates like Collect and serializes submissions byte-for-byte as JavaRosa does.

• No Flutter and no dart:io: runs on the VM, AOT, dart2js, dart2wasm and Flutter.
• Checked against real JavaRosa: about 400 conformance forms replayed against JavaRosa 6.0.0 traces (parse structure, initialization, recalculation, full walks, random-answer walks, submission XML).
• Three libraries:
  • package:dartrosa/dartrosa.dart: the session API (FormDefinition, FormSession, FormNavigator, the FormNode tree, sealed AnswerResult / FinalizeResult);
  • package:dartrosa/javarosa.dart: the JavaRosa-compatible API (FormDef, FormEntryController, FormEntryPrompt, XFormParser, XPath, plugin interfaces);
  • package:dartrosa/testing.dart: JavaRosa's Scenario and form-building DSL, for testing your own forms.

Install

dart pub add dartrosa

Example

import 'package:dartrosa/dartrosa.dart';

Future<void> main() async {
  final definition = await FormDefinition.parse(xform);
  final session = definition.createSession();

  final [name, age] = session.root.visibleChildren.cast<QuestionNode>();
  session.answer(name.index, const StringValue('Ada'));
  switch (session.answer(age.index, const IntegerValue(-3))) {
    case AnswerConstraintViolated(:final message):
      print('Rejected: $message');
    case AnswerAccepted() || AnswerRequired() || AnswerRejected():
      break;
  }
  session.answer(age.index, const UncastValue('42')); // text is parsed

  switch (session.finalize()) {
    case FinalizeSuccess(:final submission):
      print(submission.xml);
    case FinalizeFailure(:final failure):
      print('Invalid at ${failure.index.reference}');
  }
}

The complete program, with its form, is in example/example.dart.

Documentation

• API reference
• Documentation index
• Overview: what DartRosa is
• Save and resume drafts
• Architecture
• Getting started
• Migrating from JavaRosa
• Compatibility matrix
• Plugins and extension points

Related packages: dartrosa_flutter (renderer) and the ODK Collect layer: dartrosa_collect, dartrosa_external_data, dartrosa_entities, dartrosa_encryption, dartrosa_openrosa, dartrosa_calendars.

License

Apache License 2.0 (see LICENSE). DartRosa is a derivative work of JavaRosa (Apache-2.0); see the licensing notes.