Results

Every run of a task produces one RPTaskResult. Its results map holds one result per step that records something, keyed by the step identifier. RPUITask passes the result to onSubmit after the last step, and the partial result to onCancel when the participant leaves the task.

Result classes

All result classes extend RPResult, which has an identifier, a startDate and an endDate:

RPNoResult exists for JSON, but no step records it. For the details of the other results, see Read the activity result, Read the consent result and Read the permission statuses.

Results by step type

A later result for the same identifier replaces the earlier one, so the map holds the last answer to each question. In an RPNavigableOrderedTask, a result also stays in the map when the participant goes back and takes another branch. The map may then hold answers from steps that are no longer on the path the participant took.

Step results

An RPStepResult has these fields:

A question inside a form that the participant never answered has an empty results map, without an answer key.

Answer values

The type of an answer depends on the answer format:

For what each format shows and stores, see Answer formats.

Answers in code

Look up a step result with getStepResultForIdentifier(), then read its answer. This function reads the answers of the quickstart survey and of a form like the form step example:

void printAnswers(RPTaskResult result) {
  // A choice answer is a list, also for a single choice
  final sleep = result.getStepResultForIdentifier('sleepQuality');
  if (sleep is RPStepResult) {
    final answer = sleep.results[RPStepResult.DEFAULT_KEY];
    if (answer is List) {
      final values = answer.whereType<RPChoice>().map((choice) => choice.value);
      print('Sleep quality: ${values.join(', ')}');
    }
  }

  // An integer answer is the typed text
  final coffee = result.getStepResultForIdentifier('coffeeCups');
  if (coffee is RPStepResult) {
    final text = coffee.results[RPStepResult.DEFAULT_KEY] as String?;
    print('Cups of coffee: ${int.tryParse(text ?? '')}');
  }

  // A form holds one step result per question
  final aboutYou = result.getStepResultForIdentifier('aboutYou');
  if (aboutYou is RPStepResult) {
    final age = aboutYou.results['age'];
    if (age is RPStepResult) {
      print('Age: ${age.results[RPStepResult.DEFAULT_KEY]}');
    }
  }
}

Test a choice answer with is List, not is List<RPChoice>. When the app registers RPLocalizations, a choice answer in the result that onSubmit receives is a List<dynamic> that holds RPChoice objects.

Timestamps

All dates are local times of the device. JSON stores them as ISO 8601 strings without a time zone offset, such as 2026-10-27T08:15:02.118346. To compare results from several time zones, store the time zone of the device with each result.

Translated results

When the app registers RPLocalizations, onSubmit receives a copy of the result with texts in the language the participant saw:

• The answer formats of question results get translated choice texts, choice detail texts, image descriptions, integer suffixes, and slider prefixes and suffixes. The suffix of a decimal number stays as written.
• Choice answers are translated. An image choice answer keeps its description as written.
• questionTitle keeps the title as written in the task, so a translation key stays a key.
• The answers inside a form result are not translated.
• Activity, consent and permission results pass through unchanged.

onCancel receives the result without translation. For translation keys and files, see Localization.

JSON format

Every result class serializes with jsonEncode() from dart:convert, and the JSON holds the class name of each result, answer format and choice in __type. It leaves out fields that are null, except a null answer. For the full result of a survey, see Quickstart.

The result of a form nests a step result per question. For the form step example with an age and no occupation, the result is:

{
  "__type": "RPStepResult",
  "identifier": "aboutYou",
  "startDate": "2026-10-27T09:02:11.540872",
  "endDate": "2026-10-27T09:02:11.540881",
  "questionTitle": "Form Step - See titles for every question included",
  "results": {
    "age": {
      "__type": "RPStepResult",
      "identifier": "age",
      "startDate": "2026-10-27T09:01:52.117374",
      "endDate": "2026-10-27T09:01:58.902511",
      "questionTitle": "How old are you?",
      "results": { "answer": "42" },
      "answerFormat": {
        "__type": "RPIntegerAnswerFormat",
        "minValue": 18,
        "maxValue": 110,
        "suffix": "years",
        "questionType": "Integer"
      }
    },
    "occupation": {
      "__type": "RPStepResult",
      "identifier": "occupation",
      "startDate": "2026-10-27T09:01:52.117391",
      "questionTitle": "What is your occupation?",
      "results": {},
      "answerFormat": {
        "__type": "RPTextAnswerFormat",
        "hintText": "For example, nurse",
        "autoFocus": false,
        "disableHelpers": false,
        "questionType": "Text"
      }
    }
  },
  "answerFormat": { "__type": "RPFormAnswerFormat", "questionType": "Form" }
}

RPTaskResult.fromJson() reads a result back after ResearchPackage.ensureInitialized(). The answers then stay plain JSON values. A choice answer is a list of maps instead of RPChoice objects, and the questions in a form result are maps too.

For more on JSON, see JSON surveys.