answerOption.valueString crashes SDC library

[vadi2]

Describe the bug
Loading a questionnaire with answerOption.valueString instead of answerOption.valueCoding as the library expects causes a crash. valueStrings and other types are perfectly legitimate options per the spec, however.

Component
SDC library & reference app.

To Reproduce

1. Add Questionnaire below to the app
2. View Questionnaire

Additional context
Sample questionnaire:

{
  "resourceType": "Questionnaire",
  "id": "3141",
  "url": "http://example.org/fhir/Questionnaire/1",
  "title": "Questionnaire with answerOption.valueString",
  "status": "draft",
  "item": [
    {
      "linkId": "FIRSTBC",
      "type": "choice",
      "text": "Indicate if this is first breast cancer or new cancer on contralateral or ipsilateral breast:",
      "answerOption": [
        {
          "valueString": "Primary tumor"
        },
        {
          "valueString": "New ipsilateral"
        },
        {
          "valueString": "New contralateral"
        }
      ]
    }
  ]
}

[vadi2]

An example where a valueInterger would be useful. While strings are dubious, because Codings are better instead, supporting integers is quite necessary:

        {
          "linkId": "EORTC-QLQ-Q29-Q30",
          "type": "group",
          "text": "For the following questions please select the number between 1 and 7 that best applies to you, with 1 = Very poor and 7 = Excellent.",
          "item": [
            {
              "linkId": "EORTCQLQC30_Q29",
              "type": "choice",
              "text": "How would you rate your overall health during the past week?",
              "required": true,
              "answerOption": [
                {
                  "valueInteger": 1
                },
                {
                  "valueInteger": 2
                },
                {
                  "valueInteger": 3
                },
                {
                  "valueInteger": 4
                },
                {
                  "valueInteger": 5
                },
                {
                  "valueInteger": 6
                },
                {
                  "valueInteger": 7
                }
              ]
            },

[jingtang10]

thanks very much for raising this @vadi2 - @santosh-pingle is working on this

[jingtang10]

this is related (but different) to #1098. @santosh-pingle please also see the fhir chat discussion: https://chat.fhir.org/#narrow/stream/179255-questionnaire/topic/Answer.20value.20set.20and.20answers.20as.20string

[santosh-pingle]

@jingtang10
Can you please confirm whether QuestionnaireResponse will always have answerOption type as Coding, if type in Questionnaire Item is choice?

e.g

{
  "resourceType": "QuestionnaireResponse",
  "item": [
    {
      "linkId": "EORTCQLQC30_Q29",
      "answer": [
        {
          "valueCoding": {
            "code": "2",
            "display": "2"
          }
        }
      ]
    }
  ]
}

[jingtang10]

@jingtang10 Can you please confirm whether QuestionnaireResponse will always have answerOption type as Coding, if type in Questionnaire Item is choice?

e.g

{
  "resourceType": "QuestionnaireResponse",
  "item": [
    {
      "linkId": "EORTCQLQC30_Q29",
      "answer": [
        {
          "valueCoding": {
            "code": "2",
            "display": "2"
          }
        }
      ]
    }
  ]
}

so the answer type in the questionnaire response item needs to agree with the type of the questionnaire item. that's the only requirement as far as i can see.

additionally, the type of the answer option needs to agree with the type of the questionnaire item.

[jingtang10]

I think one consequence of this issue is that if we have a string/integer/date/time/whatever questionnaire item with answer options, we should render it using a "choice" widget such as dropdown. at the moment we pick the widget using the questionnaire type (e.g. if it's a string, we have text input, if it's date, we have a date picker) but it seems we need to have some logic to override that and say if any questionnaire item has answer options, we probably should use dropdown.

@vadi2 is this what other form fillers do?