Getting Started

To get started, you need an Android Studio project first. If you are new to Android, start with the Build Your First App tutorial. The rest of this document assumes familiarity with the fundamentals of Android development.

The Workflow library supports Android 24 and above. Android Studio 4.0 or above is required for Java 11 library desugaring.

This guide is intended for developers who are familiar with basic Android development with Kotlin, and proficient in working with FHIR concepts and resources.

Add the Workflow Library

Once you have set up your project in Android Studio, set the minSdk of the app to 24 and add the Workflow modules to your app's build.gradle file:

dependencies {
  implementation("com.google.android.fhir:workflow:0.1.0-alpha03")
}

Add the following Packaging Options to avoid compilation errors:

android {
  //...
  packagingOptions {
    pickFirst('META-INF/ASL-2.0.txt')
    pickFirst('META-INF/LGPL-3.0.txt')
    pickFirst('META-INF/LICENSE.md')
    pickFirst('META-INF/NOTICE.md')
    pickFirst('META-INF/sun-jaxb.episode')
  }
}

Once this is done and you have synchronized your Gradle project, proceed to the next section to start using the library's APIs.

Initialize and get a FhirOperator

All workflow requests are made through a FhirOperator instance, which should be initialized in the Application.onCreate function, together with the Engine's initialization. The FhirOperator is your main access point to all clinical decision support implementations in the SDK.

The snippet below demonstrates how to pre-load a single operator to your application. Notice how the Workflow module requires a choice of FhirVersion, R4 in this case.

class MyApplication : Application() {
 private val inSync = LazyThreadSafetyMode.SYNCHRONIZED

 // Only initiate when used for the first time, not when the app is created.
 private val fhirEngine: FhirEngine by lazy(inSync) { FhirEngineProvider.getInstance(this) }
 private val fhirContext: FhirContext by lazy(inSync) { FhirContext.forCached(FhirVersionEnum.R4) }
 private val fhirOperator: FhirOperator by lazy(inSync) { FhirOperator(fhirContext, fhirEngine) }

 override fun onCreate() {
   super.onCreate()

   FhirEngineProvider.init(
     FhirEngineConfiguration(
       enableEncryptionIfSupported = true,
       DatabaseErrorStrategy.RECREATE_AT_OPEN
     )
   )

   thread {
     fhirOperator //Initializes the object in the background.
   }
 }

 companion object {
   fun fhirEngine(context: Context) = (context.applicationContext as MyApplication).fhirEngine
   fun fhirContext(context: Context) = (context.applicationContext as MyApplication).fhirContext
   fun fhirOperator(context: Context) = (context.applicationContext as MyApplication).fhirOperator
 }
}

Don't forget to add the custom MyApplication to the AndroidManifest.xml

<application
   android:name=".MyApplication"
   <!-- ... ->
</application>

Use FhirOperator APIs

1. Evaluate Individual Subject Matters:

fhirOperator.evaluateMeasure(
 url = "http://fhir.org/guides/who/anc-cds/Measure/ANCIND01",
 start = "2020-01-01",
 end = "2020-01-31",
 reportType = "subject",
 subject = "charity-otala-1",
 practitioner = "jane",
 lastReceivedOn = null
)

2. Evaluate Population Matters:

val measureReport : MeasureReport =
 fhirOperator.evaluateMeasure(
   url = "http://fhir.org/guides/who/anc-cds/Measure/ANCIND01",
   start = "2019-01-01",
   end = "2021-12-31",
   reportType = "population",
   subject = null,
   practitioner = "jane",
   lastReceivedOn = null
 )

3. Generate Care Plan for a Patient:

val plan: CarePlan = fhirOperator.generateCarePlan(
 planDefinitionId = "plandefinition-RuleFilters-1.0.0",
 patientId = "Reportable",
 encounterId = "reportable-encounter"
)

See FhirOperatorTest.kt for more details on how to set up data.