enableWhen operator "=" and "!=" not working as expected

[StefanKlose]

Hi,

I want to use the enableWhen-feature. There seems to be an issue with the "=" and "!=" operators (for both integer and string answers).

I provided a small json excerpt (see below).

with this json I would expect that the text "Text 1" is only displayed, when I fully type "hello". instead it is shown on the first typed charactor.

can you reproduce and fix this?

  {
    "linkId": "1",
    "type": "string"
},
{
    "linkId": "2",
    "text": "Text 1",
    "type": "display",
    "enableWhen": [ 
        {
            "question": "1",
            "operator": "=",
            "answerString": "hello"
        }
    ]
},

kind regards
Dr. Stefan Klose

PS: a colleague just told me that this feature is not implemented (yet???)

[fjwong]

@StefanKlose Thank you for the report. We can reproduce this behavior on our side as well.

It appears the enableWhen functionality is partially implemented at the moment, as stated in the SDC capabilities document: https://github.com/sujrd/faiadashu/blob/develop/doc/sdc-capabilities.md#enablewhen

This shouldn't be complex to implement, but it may take some time for us to actually be able to implement it and test it for most question types, and cannot provide an estimated date for this to make it into a release. We will discuss this with the rest of the team and try to work on it once we get some time available.

If you need this functionality rather quickly, you can workaround it by using an enableWhenExpression extension instead in the meantime. The following example should work for your case:

{
  "resourceType": "Questionnaire",
  "status": "draft",
  "item": [
    { 
      "type": "string",
      "linkId": "1",
      "text": "Question 1"
    },
    {
      "type": "display",
      "linkId": "2",
      "text": "Text 1",
      "enableBehavior": "all",
      "extension": [
        {
          "url": "http://hl7.org/fhir/uv/sdc/StructureDefinition/sdc-questionnaire-enableWhenExpression",
          "valueExpression": {
            "language": "text/fhirpath",
            "name": "Show if Q1 = hello",
            "expression": "%resource.item.where(linkId='1').answer.valueString = 'hello'"
          }
        }
      ]
    }
  ]
}

[StefanKlose]

thanks for the reply :)