Support evaluation of variables, launchContext and other FHIR contexts for cqf-calculatedValue expressions

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

@@ -30,12 +30,14 @@ import com.google.android.fhir.datacapture.expressions.EnabledAnswerOptionsEvalu
 import com.google.android.fhir.datacapture.extensions.EntryMode
 import com.google.android.fhir.datacapture.extensions.addNestedItemsToAnswer
 import com.google.android.fhir.datacapture.extensions.allItems
+import com.google.android.fhir.datacapture.extensions.cqfCalculatedValueExpression
 import com.google.android.fhir.datacapture.extensions.cqfExpression
 import com.google.android.fhir.datacapture.extensions.createQuestionnaireResponseItem
 import com.google.android.fhir.datacapture.extensions.entryMode
 import com.google.android.fhir.datacapture.extensions.filterByCodeInNameExtension
 import com.google.android.fhir.datacapture.extensions.flattened
 import com.google.android.fhir.datacapture.extensions.hasDifferentAnswerSet
+import com.google.android.fhir.datacapture.extensions.isCqfCalculatedValue
 import com.google.android.fhir.datacapture.extensions.isDisplayItem
 import com.google.android.fhir.datacapture.extensions.isFhirPath
 import com.google.android.fhir.datacapture.extensions.isHidden
@@ -67,13 +69,14 @@ import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.flow.withIndex
 import org.hl7.fhir.r4.model.Base
-import org.hl7.fhir.r4.model.Element
+import org.hl7.fhir.r4.model.Expression
 import org.hl7.fhir.r4.model.Questionnaire
 import org.hl7.fhir.r4.model.Questionnaire.QuestionnaireItemComponent
 import org.hl7.fhir.r4.model.QuestionnaireResponse
 import org.hl7.fhir.r4.model.QuestionnaireResponse.QuestionnaireResponseItemAnswerComponent
 import org.hl7.fhir.r4.model.QuestionnaireResponse.QuestionnaireResponseItemComponent
 import org.hl7.fhir.r4.model.Resource
+import org.hl7.fhir.r4.model.Type
 import timber.log.Timber
 
 internal class QuestionnaireViewModel(application: Application, state: SavedStateHandle) :
@@ -571,21 +574,21 @@ internal class QuestionnaireViewModel(application: Application, state: SavedStat
       }
   }
 
-  private fun resolveCqfExpression(
+  private fun resolveExpression(
     questionnaireItem: QuestionnaireItemComponent,
     questionnaireResponseItem: QuestionnaireResponseItemComponent,
-    element: Element,
-  ): List<Base> {
-    val cqfExpression = element.cqfExpression ?: return emptyList()
-
-    if (!cqfExpression.isFhirPath) {
-      throw UnsupportedOperationException("${cqfExpression.language} not supported yet")
+    expression: Expression,
+  ): Base? {
+    if (!expression.isFhirPath) {
+      throw UnsupportedOperationException("${expression.language} not supported yet")
     }
-    return expressionEvaluator.evaluateExpression(
-      questionnaireItem,
-      questionnaireResponseItem,
-      cqfExpression,
-    )
+    return expressionEvaluator
+      .evaluateExpression(
+        questionnaireItem,
+        questionnaireResponseItem,
+        expression,
+      )
+      .singleOrNull()
   }
 
   private fun removeDisabledAnswers(
@@ -678,6 +681,27 @@ internal class QuestionnaireViewModel(application: Application, state: SavedStat
     )
   }
 
+  private fun resolveCqfCalculatedValueExpressions(
+    questionnaireItem: QuestionnaireItemComponent,
+    questionnaireResponseItem: QuestionnaireResponseItemComponent,
+  ) {
+    questionnaireItem.extension
+      .filter { it.hasValue() && it.value.isCqfCalculatedValue }
+      .forEach { extension ->
+        val currentExtensionValue = extension.value
+        val currentExtensionValueExtensions = currentExtensionValue.extension
+        val evaluatedCqfCalculatedValue =
+          currentExtensionValue.cqfCalculatedValueExpression?.let {
+            resolveExpression(questionnaireItem, questionnaireResponseItem, it) as? Type
+          }
+        // add previous extensions to the evaluated value
+        evaluatedCqfCalculatedValue?.setExtension(currentExtensionValueExtensions)
+        if (evaluatedCqfCalculatedValue != null) {
+          extension.setValue(evaluatedCqfCalculatedValue)
+        }
+      }
+  }
+
   /**
    * Returns the list of [QuestionnaireViewItem]s generated for the questionnaire items and
    * questionnaire response items.
@@ -716,6 +740,9 @@ internal class QuestionnaireViewModel(application: Application, state: SavedStat
 
     restoreFromDisabledQuestionnaireItemAnswersCache(questionnaireResponseItem)
 
+    // Evaluate cqf-calculatedValues
+    resolveCqfCalculatedValueExpressions(questionnaireItem, questionnaireResponseItem)
+
     // Determine the validation result, which will be displayed on the item itself
     val validationResult =
       if (
@@ -726,18 +753,19 @@ internal class QuestionnaireViewModel(application: Application, state: SavedStat
         QuestionnaireResponseItemValidator.validate(
           questionnaireItem,
           questionnaireResponseItem.answer,
-          [email protected](),
+          context = [email protected](),
         )
       } else {
         NotValidated
       }
 
     // Set question text dynamically from CQL expression
-    questionnaireResponseItem.apply {
-      resolveCqfExpression(questionnaireItem, this, questionnaireItem.textElement)
-        .firstOrNull()
-        ?.let { text = it.primitiveValue() }
+    questionnaireItem.textElement.cqfExpression?.let { expression ->
+      resolveExpression(questionnaireItem, questionnaireResponseItem, expression)
+        ?.primitiveValue()
+        ?.let { questionnaireResponseItem.text = it }
     }
+
     val (enabledQuestionnaireAnswerOptions, disabledQuestionnaireResponseAnswers) =
       answerOptionsEvaluator.evaluate(
         questionnaireItem,

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

@@ -26,6 +26,8 @@ import ca.uhn.fhir.util.UrlUtil
 import com.google.android.fhir.datacapture.DataCapture
 import com.google.android.fhir.datacapture.QuestionnaireViewHolderType
 import com.google.android.fhir.datacapture.fhirpath.evaluateToDisplay
+import com.google.android.fhir.datacapture.validation.MAX_VALUE_EXTENSION_URL
+import com.google.android.fhir.datacapture.validation.MIN_VALUE_EXTENSION_URL
 import com.google.android.fhir.getLocalizedText
 import java.math.BigDecimal
 import java.time.LocalDate
@@ -82,9 +84,6 @@ internal const val EXTENSION_CHOICE_ORIENTATION_URL =
 internal const val EXTENSION_CHOICE_COLUMN_URL: String =
   "http://hl7.org/fhir/uv/sdc/StructureDefinition/sdc-questionnaire-choiceColumn"
 
-internal const val EXTENSION_CQF_CALCULATED_VALUE_URL: String =
-  "http://hl7.org/fhir/StructureDefinition/cqf-calculatedValue"
-
 internal const val EXTENSION_DISPLAY_CATEGORY_URL =
   "http://hl7.org/fhir/StructureDefinition/questionnaire-displayCategory"
 
@@ -293,6 +292,14 @@ val Questionnaire.QuestionnaireItemComponent.sliderStepValue: Int?
     return null
   }
 
+/** The inclusive lower bound on the range of allowed answer values. */
+internal val Questionnaire.QuestionnaireItemComponent.minValue
+  get() = getExtensionByUrl(MIN_VALUE_EXTENSION_URL)?.value?.valueOrCalculateValue()
+
+/** The inclusive upper bound on the range of allowed answer values. */
+internal val Questionnaire.QuestionnaireItemComponent.maxValue
+  get() = getExtensionByUrl(MAX_VALUE_EXTENSION_URL)?.value?.valueOrCalculateValue()
+
 // ********************************************************************************************** //
 //                                                                                                //
 // Additional display utilities: display item control, localized text spanned,                    //

datacapture/src/main/java/com/google/android/fhir/datacapture/extensions/MoreTypes.kt

@@ -22,6 +22,7 @@ import com.google.android.fhir.datacapture.fhirpath.fhirPathEngine
 import com.google.android.fhir.datacapture.views.factories.localDate
 import com.google.android.fhir.datacapture.views.factories.localTime
 import com.google.android.fhir.getLocalizedText
+import org.hl7.fhir.exceptions.FHIRException
 import org.hl7.fhir.r4.model.Attachment
 import org.hl7.fhir.r4.model.BooleanType
 import org.hl7.fhir.r4.model.CodeType
@@ -38,6 +39,7 @@ import org.hl7.fhir.r4.model.Reference
 import org.hl7.fhir.r4.model.StringType
 import org.hl7.fhir.r4.model.Type
 import org.hl7.fhir.r4.model.UriType
+import timber.log.Timber
 
 /**
  * Returns the string representation of a [PrimitiveType].
@@ -97,10 +99,8 @@ private fun getDisplayString(type: Type, context: Context): String? =
 
 private fun getValueString(type: Type): String? =
   when (type) {
-    is DateType,
-    is DateTimeType,
-    is StringType, -> type.asStringValue()
-    is Quantity -> type.value.toString()
+    is StringType -> type.getLocalizedText() ?: type.valueAsString
+    is Quantity -> type.takeIf { it.hasValue() }?.value?.toString()
     else -> (type as? PrimitiveType<*>)?.valueAsString
   }
 
@@ -125,15 +125,29 @@ internal fun Coding.toCodeType(): CodeType {
 }
 
 fun Type.valueOrCalculateValue(): Type {
-  return if (this.hasExtension()) {
-    this.extension
-      .firstOrNull { it.url == EXTENSION_CQF_CALCULATED_VALUE_URL }
-      ?.let { extension ->
-        val expression = (extension.value as Expression).expression
-        fhirPathEngine.evaluate(this, expression).singleOrNull()?.let { it as Type }
+  return if (getValueString(this) != null) {
+    this
+  } else {
+    this.cqfCalculatedValueExpression?.let { expression ->
+      try {
+        fhirPathEngine.evaluate(this, expression.expression).singleOrNull() as? Type
+      } catch (e: FHIRException) {
+        Timber.w("Could not evaluate expression with FHIRPathEngine", e)
+        null
       }
+    }
       ?: this
-  } else {
-    this
   }
 }
+
+internal val Type.isCqfCalculatedValue
+  get() = this.hasExtension(EXTENSION_CQF_CALCULATED_VALUE_URL)
+
+internal val Type.cqfCalculatedValueExpression
+  get() =
+    this.takeIf { isCqfCalculatedValue }
+      ?.getExtensionByUrl(EXTENSION_CQF_CALCULATED_VALUE_URL)
+      ?.value as? Expression
+
+internal const val EXTENSION_CQF_CALCULATED_VALUE_URL: String =
+  "http://hl7.org/fhir/StructureDefinition/cqf-calculatedValue"

datacapture/src/main/java/com/google/android/fhir/datacapture/validation/AnswerExtensionConstraintValidator.kt

@@ -35,7 +35,10 @@ import org.hl7.fhir.r4.model.QuestionnaireResponse
 internal open class AnswerExtensionConstraintValidator(
   val url: String,
   val predicate:
-    (Extension, QuestionnaireResponse.QuestionnaireResponseItemAnswerComponent) -> Boolean,
+    (
+      Extension,
+      QuestionnaireResponse.QuestionnaireResponseItemAnswerComponent,
+    ) -> Boolean,
   val messageGenerator: (Extension, Context) -> String,
 ) : AnswerConstraintValidator {
   override fun validate(

datacapture/src/main/java/com/google/android/fhir/datacapture/validation/MaxValueValidator.kt

@@ -22,9 +22,7 @@ import com.google.android.fhir.datacapture.R
 import com.google.android.fhir.datacapture.extensions.getValueAsString
 import com.google.android.fhir.datacapture.extensions.valueOrCalculateValue
 import org.hl7.fhir.r4.model.Extension
-import org.hl7.fhir.r4.model.Questionnaire
 import org.hl7.fhir.r4.model.QuestionnaireResponse
-import org.hl7.fhir.r4.model.Type
 
 internal const val MAX_VALUE_EXTENSION_URL = "http://hl7.org/fhir/StructureDefinition/maxValue"
 
@@ -44,11 +42,4 @@ internal object MaxValueValidator :
         extension.value?.valueOrCalculateValue()?.getValueAsString(context),
       )
     },
-  ) {
-
-  fun getMaxValue(questionnaireItemComponent: Questionnaire.QuestionnaireItemComponent): Type? {
-    return questionnaireItemComponent.extension
-      .firstOrNull { it.url == MAX_VALUE_EXTENSION_URL }
-      ?.let { it.value?.valueOrCalculateValue() }
-  }
-}
+  )

datacapture/src/main/java/com/google/android/fhir/datacapture/validation/MinValueValidator.kt

@@ -22,9 +22,7 @@ import com.google.android.fhir.datacapture.R
 import com.google.android.fhir.datacapture.extensions.getValueAsString
 import com.google.android.fhir.datacapture.extensions.valueOrCalculateValue
 import org.hl7.fhir.r4.model.Extension
-import org.hl7.fhir.r4.model.Questionnaire
 import org.hl7.fhir.r4.model.QuestionnaireResponse
-import org.hl7.fhir.r4.model.Type
 
 internal const val MIN_VALUE_EXTENSION_URL = "http://hl7.org/fhir/StructureDefinition/minValue"
 
@@ -44,13 +42,4 @@ internal object MinValueValidator :
         extension.value?.valueOrCalculateValue()?.getValueAsString(context),
       )
     },
-  ) {
-
-  internal fun getMinValue(
-    questionnaireItemComponent: Questionnaire.QuestionnaireItemComponent,
-  ): Type? {
-    return questionnaireItemComponent.extension
-      .firstOrNull { it.url == MIN_VALUE_EXTENSION_URL }
-      ?.let { it.value?.valueOrCalculateValue() }
-  }
-}
+  )