Get started with Data Capture

Goal and scope​

Add the SDK to a Compose Multiplatform (or Android Compose) project and render a Questionnaire end to end. That means display, fill, validate, submit.

Prerequisites​

• A project already using Compose Multiplatform with Material 3, or Jetpack Compose on Android (minSdk 26).
• A FHIR R4 Questionnaire as a JSON string. Any of the catalog app's bundled questionnaires in the repository works as a first input.
• Your platform on the support matrix.

Add the dependency​

kotlin {
  sourceSets {
    commonMain.dependencies {
      implementation("dev.ohs.fhir:fhir-data-capture:2.0.0-alpha02")
      implementation("dev.ohs.fhir:fhir-model:1.0.0-beta05")
    }
  }
}

Android-only projects put the same coordinates in the ordinary dependencies block. The model dependency is explicit because your code handles the submitted response as a model type. Keep its version aligned with what the SDK builds against, as listed in versions and compatibility.

Render a Questionnaire​

import dev.ohs.fhir.datacapture.Questionnaire
import dev.ohs.fhir.model.r4.QuestionnaireResponse
import kotlinx.coroutines.launch

@Composable
fun IntakeForm(questionnaireJson: String, onDone: (QuestionnaireResponse) -> Unit) {
  val scope = rememberCoroutineScope()
  Questionnaire(
    questionnaireJson = questionnaireJson,
    onSubmit = { getResponse ->
      scope.launch {
        val response = getResponse() // runs validation and throws if invalid
        onDone(response)
      }
    },
    onCancel = { /* dismiss the form */ },
  )
}

Two things in that signature matter.

• onSubmit does not hand you a response. It hands you a suspend getter. Calling getResponse() runs validation. If answers are invalid, the SDK shows its validation dialog and the getter throws a CancellationException instead of returning. The dialog offers a submit-anyway path by default, which delivers the response without validation, so set showSubmitAnywayWhenValidationFails = false when invalid data must never leave the form.
• The composable takes the Questionnaire as a JSON string and returns a typed QuestionnaireResponse from Kotlin FHIR. Serialize it with a plain Json instance when you need to store or transmit it.

Pre-filling and context​

Two optional parameters cover the common launch scenarios.

• questionnaireResponseJson takes a previously saved response to continue editing.
• questionnaireLaunchContextMap supplies SDC launch context, meaning named resources (such as the current patient) that the Questionnaire's expressions can reference.

Checkpoint​

The form renders your Questionnaire's items, a required question left empty blocks submission with a validation message, and completing the form delivers a QuestionnaireResponse whose item answers echo what you entered.

Next step​

Control rendering behavior with configuration flags, review flows, and resolvers.