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Component overview

Kotlin FHIR Data Capture

Collecting, validating, and processing structured healthcare data with FHIR Questionnaires, rendered in Compose Multiplatform.

What it is​

Kotlin FHIR Data Capture turns a FHIR Questionnaire into a working, validated form. Hand it a Questionnaire's JSON and it renders the questions with Material 3 components, applies the Questionnaire's behavior for skip logic, calculated values, and answer options, validates the answers, and returns a QuestionnaireResponse. It implements FHIR's Structured Data Capture (SDC) patterns for R4, built on Compose Multiplatform so the same form code runs on Android, iOS, desktop, and the browser.

It is the Kotlin Multiplatform successor to the Android FHIR SDK's data-capture library, rebuilt from Android Views onto Compose.

What you get​

  • A single entry point. The Questionnaire composable takes Questionnaire JSON in and hands a QuestionnaireResponse out through an onSubmit callback that runs validation first.
  • Built-in renderers for the standard question types. These cover text in single and multi-line, integer and decimal, boolean, date, time and date-time pickers, radio groups, checkboxes, dropdowns, autocomplete, dialog selection, sliders, quantities, phone numbers, attachments, groups, and display items.
  • SDC behavior driven by the Questionnaire itself. enableWhen and enable-expressions, calculated and initial expressions, answer expressions and answer ValueSets, launch context, entry mode, and paginated layout are expressed in the Questionnaire resource and evaluated at runtime with Kotlin FHIRPath.
  • Validation from the Questionnaire's constraints, including required, min and max values, length, regex, and constraint extensions, surfaced in the UI before submission.
  • Template-based extraction, turning a completed response into real FHIR resources (a transaction Bundle) using the SDC template-extraction extensions.
  • An extension point for custom widgets, so a question can render as anything you can write in Compose. The repository's catalog app demonstrates barcode-scanner and geolocation widgets built this way.

The catalog app​

The repository ships a catalog application with several dozen small Questionnaires, one per component, behavior, and layout, from component_slider to behavior_skip_logic to layout_paginated. It runs on all four platforms and shows each item type and SDC behavior in isolation.

What it is not​

  • Not storage and not sync. The SDK is purely in-memory. Persisting the QuestionnaireResponse (or extracted resources) is your application's job, typically with Kotlin FHIR Engine, on which this SDK does not depend.
  • R4 only, matching the other SDK.
  • FHIRPath expressions only. Questionnaires using CQL or other expression languages raise an error at the offending expression.
  • Extraction is template-based only. StructureMap-based extraction is not implemented, and definition-based extraction is not part of the published library.
  • Unsupported item types fail loudly. An unrecognized question type raises rather than rendering a degraded fallback.

Next step​

Render your first Questionnaire.