Variables Usage

Smart Forms supports the fhirpath and x-fhir-query variable extensions. Each key contains a Record<linkId, variable>.

Since the root level (the Questionnaire itself) does not have a linkId, extensions at the root level have a key of QuestionnaireLevel.

warning

Smart Forms having the QuestionnaireLevel key for root-level extensions might actually clash with items that have the same linkId. This is a known issue and will be addressed in the future.

Live Editor

function App() {
  const variables = useQuestionnaireStore.use.variables();

  return (
    <>
      <YourBaseRendererWrapper questionnaire={qCalculatedExpressionBMICalculator} />
      <JsonViewer hookName="variables" data={variables} />
    </>
  );
}

Result