Remove Engine dependency from SDC. (#1742)

* Added interface to resolve x-fhir-query for library

* Review changes

* Removed unnecessary imports

datacapture/build.gradle.kts

@@ -73,8 +73,6 @@ dependencies {
 
  coreLibraryDesugaring(Dependencies.desugarJdkLibs)
 
- debugImplementation(project(":engine"))
-
  implementation(Dependencies.androidFhirCommon)
  implementation(Dependencies.Androidx.appCompat)
  implementation(Dependencies.Androidx.constraintLayout)
@@ -92,8 +90,6 @@ dependencies {
  implementation(Dependencies.lifecycleExtensions)
  implementation(Dependencies.timber)
 
- releaseImplementation(Dependencies.androidFhirEngine)
-
  testImplementation(Dependencies.AndroidxTest.core)
  testImplementation(Dependencies.AndroidxTest.fragmentTesting)
  testImplementation(Dependencies.Kotlin.kotlinTestJunit)

datacapture/src/main/java/com/google/android/fhir/datacapture/DataCaptureConfig.kt

@@ -20,6 +20,7 @@ import android.app.Application
 import com.google.android.fhir.datacapture.DataCaptureConfig.Provider
 import org.hl7.fhir.r4.context.SimpleWorkerContext
 import org.hl7.fhir.r4.model.Coding
+import org.hl7.fhir.r4.model.Resource
 import org.hl7.fhir.r4.model.StructureMap
 import org.hl7.fhir.utilities.npm.NpmPackage
 
@@ -45,7 +46,13 @@ data class DataCaptureConfig(
  * should try to include the smallest [NpmPackage] possible that contains only the resources
  * needed by [StructureMap]s used by the client app.
  */
- var npmPackage: NpmPackage? = null
+ var npmPackage: NpmPackage? = null,
+
+ /**
+ * A [XFhirQueryResolver] may be set by the client to resolve x-fhir-query for the library. See
+ * https://build.fhir.org/ig/HL7/sdc/expressions.html#fhirquery for more details.
+ */
+ var xFhirQueryResolver: XFhirQueryResolver? = null,
 ) {
 
  internal val simpleWorkerContext: SimpleWorkerContext by lazy {
@@ -75,3 +82,14 @@ data class DataCaptureConfig(
 interface ExternalAnswerValueSetResolver {
  suspend fun resolve(uri: String): List<Coding>
 }
+
+/**
+ * Resolves resources based on the provided xFhir query. This allows the library to resolve
+ * x-fhir-query answer expressions.
+ *
+ * NOTE: The result of the resolution may be cached to improve performance. In other words, the
+ * resolver may be called only once after which the Resources may be used multiple times in the UI.
+ */
+fun interface XFhirQueryResolver {
+ suspend fun resolve(xFhirQuery: String): List<Resource>
+}

datacapture/src/main/java/com/google/android/fhir/datacapture/MoreQuestionnaireItemComponents.kt

@@ -21,7 +21,6 @@ import androidx.core.text.HtmlCompat
 import com.google.android.fhir.datacapture.common.datatype.asStringValue
 import com.google.android.fhir.datacapture.utilities.evaluateToDisplay
 import com.google.android.fhir.getLocalizedText
-import com.google.android.fhir.logicalId
 import org.hl7.fhir.r4.model.Base
 import org.hl7.fhir.r4.model.BooleanType
 import org.hl7.fhir.r4.model.CodeType
@@ -545,3 +544,8 @@ fun List<Questionnaire.QuestionnaireItemComponent>.flattened():
  */
 fun Questionnaire.QuestionnaireItemComponent.getNestedQuestionnaireResponseItems() =
  item.map { it.createQuestionnaireResponseItem() }
+
+val Resource.logicalId: String
+ get() {
+ return this.idElement?.idPart.orEmpty()
+ }

datacapture/src/main/java/com/google/android/fhir/datacapture/QuestionnaireViewModel.kt

@@ -25,7 +25,6 @@ import androidx.lifecycle.viewModelScope
 import ca.uhn.fhir.context.FhirContext
 import ca.uhn.fhir.context.FhirVersionEnum
 import ca.uhn.fhir.parser.IParser
-import com.google.android.fhir.FhirEngineProvider
 import com.google.android.fhir.datacapture.enablement.EnablementEvaluator
 import com.google.android.fhir.datacapture.fhirpath.ExpressionEvaluator.detectExpressionCyclicDependency
 import com.google.android.fhir.datacapture.fhirpath.ExpressionEvaluator.evaluateCalculatedExpressions
@@ -38,7 +37,6 @@ import com.google.android.fhir.datacapture.validation.QuestionnaireResponseValid
 import com.google.android.fhir.datacapture.validation.Valid
 import com.google.android.fhir.datacapture.validation.ValidationResult
 import com.google.android.fhir.datacapture.views.QuestionnaireItemViewItem
-import com.google.android.fhir.search.search
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
@@ -57,7 +55,9 @@ internal class QuestionnaireViewModel(application: Application, state: SavedStat
  AndroidViewModel(application) {
 
  private val parser: IParser by lazy { FhirContext.forCached(FhirVersionEnum.R4).newJsonParser() }
- private val fhirEngine by lazy { FhirEngineProvider.getInstance(application) }
+ private val xFhirQueryResolver: XFhirQueryResolver? by lazy {
+ DataCapture.getConfiguration(application).xFhirQueryResolver
+ }
 
  /** The current questionnaire as questions are being answered. */
  internal val questionnaire: Questionnaire
@@ -448,13 +448,18 @@ internal class QuestionnaireViewModel(application: Application, state: SavedStat
  expression: Expression,
  ): List<Questionnaire.QuestionnaireItemAnswerOptionComponent> {
  val data =
- if (expression.isXFhirQuery) fhirEngine.search(expression.expression)
- else if (expression.isFhirPath)
+ if (expression.isXFhirQuery) {
+ checkNotNull(xFhirQueryResolver) {
+ "XFhirQueryResolver cannot be null. Please provide the XFhirQueryResolver via DataCaptureConfig."
+ }
+ xFhirQueryResolver!!.resolve(expression.expression)
+ } else if (expression.isFhirPath) {
  fhirPathEngine.evaluate(questionnaireResponse, expression.expression)
- else
+ } else {
  throw UnsupportedOperationException(
  "${expression.language} not supported for answer-expression yet"
  )
+ }
 
  return item.extractAnswerOptions(data)
  }

datacapture/src/test/java/com/google/android/fhir/datacapture/QuestionnaireViewModelTest.kt

@@ -35,7 +35,6 @@ import com.google.android.fhir.datacapture.testing.DataCaptureTestApplication
 import com.google.android.fhir.datacapture.validation.Invalid
 import com.google.android.fhir.datacapture.validation.NotValidated
 import com.google.android.fhir.datacapture.views.QuestionnaireItemViewItem
-import com.google.android.fhir.logicalId
 import com.google.android.fhir.testing.FhirEngineProviderTestRule
 import com.google.common.truth.Truth.assertThat
 import java.util.Calendar
@@ -62,7 +61,7 @@ import org.hl7.fhir.r4.model.QuestionnaireResponse
 import org.hl7.fhir.r4.model.StringType
 import org.hl7.fhir.r4.model.ValueSet
 import org.hl7.fhir.r4.utils.ToolingExtensions
-import org.junit.Assert
+import org.junit.Assert.assertThrows
 import org.junit.Before
 import org.junit.Ignore
 import org.junit.Rule
@@ -2894,13 +2893,13 @@ class QuestionnaireViewModelTest {
  fun `resolveAnswerExpression() should return questionnaire item answer options for answer expression and choice column`() =
  runBlocking {
  val practitioner =
- Practitioner()
- .apply {
-  id = UUID.randomUUID().toString()
-  active = true
-  addName(HumanName().apply { this.family = "John" })
-  }
-  .also { fhirEngine.create(it) }
+ Practitioner().apply {
+ id = UUID.randomUUID().toString()
+ active = true
+ addName(HumanName().apply { this.family = "John" })
+ }
+ ApplicationProvider.getApplicationContext<DataCaptureTestApplication>()
+ .dataCaptureConfiguration = DataCaptureConfig(xFhirQueryResolver = { listOf(practitioner) })
 
  val questionnaire =
  Questionnaire().apply {
@@ -2939,6 +2938,47 @@ class QuestionnaireViewModelTest {
  .isEqualTo("Practitioner/${practitioner.logicalId}")
  }
 
+ @Test
+ fun `resolveAnswerExpression() should throw exception when XFhirQueryResolver is not provided`() {
+ val questionnaire =
+ Questionnaire().apply {
+ addItem(
+ Questionnaire.QuestionnaireItemComponent().apply {
+ linkId = "a"
+ text = "answer expression question text"
+ type = Questionnaire.QuestionnaireItemType.REFERENCE
+ extension =
+ listOf(
+ Extension(
+ "http:https://hl7.org/fhir/uv/sdc/StructureDefinition/sdc-questionnaire-answerExpression",
+ Expression().apply {
+ this.expression = "Practitioner?active=true"
+ this.language = Expression.ExpressionLanguage.APPLICATION_XFHIRQUERY.toCode()
+ }
+ ),
+ Extension(
+ "http:https://hl7.org/fhir/uv/sdc/StructureDefinition/sdc-questionnaire-choiceColumn"
+ )
+ .apply {
+ this.addExtension(Extension("path", StringType("id")))
+ this.addExtension(Extension("label", StringType("name")))
+ this.addExtension(Extension("forDisplay", BooleanType(true)))
+ }
+ )
+ }
+ )
+ }
+ state.set(EXTRA_QUESTIONNAIRE_JSON_STRING, printer.encodeResourceToString(questionnaire))
+ val viewModel = QuestionnaireViewModel(context, state)
+ val exception =
+ assertThrows(null, IllegalStateException::class.java) {
+ runBlocking { viewModel.resolveAnswerExpression(questionnaire.itemFirstRep) }
+ }
+ assertThat(exception.message)
+ .isEqualTo(
+ "XFhirQueryResolver cannot be null. Please provide the XFhirQueryResolver via DataCaptureConfig."
+ )
+ }
  // Test cases for submit button
 
  @Test
@@ -3602,7 +3642,7 @@ class QuestionnaireViewModelTest {
  }
 
  val exception =
- Assert.assertThrows(null, IllegalStateException::class.java) {
+ assertThrows(null, IllegalStateException::class.java) {
  createQuestionnaireViewModel(questionnaire)
  }
  assertThat(exception.message)
@@ -3667,7 +3707,7 @@ class QuestionnaireViewModelTest {
  }
 
  val exception =
- Assert.assertThrows(null, IllegalStateException::class.java) {
+ assertThrows(null, IllegalStateException::class.java) {
  createQuestionnaireViewModel(questionnaire)
  }
  assertThat(exception.message)