Evaluate cqf-calculatedValue expressions using ExpressionEvaluator

to add support for variable expressions, launchContexts and %resource expressions

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

@@ -27,6 +27,7 @@ import ca.uhn.fhir.context.FhirVersionEnum
 import ca.uhn.fhir.parser.IParser
 import com.google.android.fhir.datacapture.enablement.EnablementEvaluator
 import com.google.android.fhir.datacapture.expressions.EnabledAnswerOptionsEvaluator
+import com.google.android.fhir.datacapture.extensions.EXTENSION_CQF_CALCULATED_VALUE_URL
 import com.google.android.fhir.datacapture.extensions.EntryMode
 import com.google.android.fhir.datacapture.extensions.addNestedItemsToAnswer
 import com.google.android.fhir.datacapture.extensions.allItems
@@ -68,12 +69,14 @@ 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) :
@@ -579,6 +582,21 @@ internal class QuestionnaireViewModel(application: Application, state: SavedStat
     )
   }
 
+  private fun resolveCqfCalculatedValueExpression(
+    questionnaireItem: QuestionnaireItemComponent,
+    questionnaireResponseItem: QuestionnaireResponseItemComponent,
+    expression: Expression,
+  ): Type? {
+    if (!expression.isFhirPath) {
+      throw UnsupportedOperationException("${expression.language} not supported yet")
+    }
+
+    return expressionEvaluator
+      .evaluateExpression(questionnaireItem, questionnaireResponseItem, expression)
+      .singleOrNull()
+      ?.let { it as Type }
+  }
+
   private fun removeDisabledAnswers(
     questionnaireItem: QuestionnaireItemComponent,
     questionnaireResponseItem: QuestionnaireResponseItemComponent,
@@ -707,6 +725,23 @@ internal class QuestionnaireViewModel(application: Application, state: SavedStat
 
     restoreFromDisabledQuestionnaireItemAnswersCache(questionnaireResponseItem)
 
+    // Evaluate cqf-calculatedValues
+    questionnaireItem.extension
+      .filter { it.hasValue() && it.value.hasExtension(EXTENSION_CQF_CALCULATED_VALUE_URL) }
+      .forEach { extension ->
+        val expression =
+          extension.value.getExtensionByUrl(EXTENSION_CQF_CALCULATED_VALUE_URL).value as Expression
+        resolveCqfCalculatedValueExpression(
+            questionnaireItem,
+            questionnaireResponseItem,
+            expression,
+          )
+          ?.let {
+            it.apply { setExtension(extension.value.extension) }
+            extension.setValue(it)
+          }
+      }
+
     // Determine the validation result, which will be displayed on the item itself
     val validationResult =
       if (
@@ -717,7 +752,7 @@ internal class QuestionnaireViewModel(application: Application, state: SavedStat
         QuestionnaireResponseItemValidator.validate(
           questionnaireItem,
           questionnaireResponseItem.answer,
-          this@QuestionnaireViewModel.getApplication(),
+          context = this@QuestionnaireViewModel.getApplication(),
         )
       } else {
         NotValidated

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

@@ -82,9 +82,6 @@ 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"
 

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

@@ -97,10 +97,8 @@ 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 +123,19 @@ internal fun Coding.toCodeType(): CodeType {
 }
 
 fun Type.valueOrCalculateValue(): Type {
-  return if (this.hasExtension()) {
-    this.extension
-      .firstOrNull { it.url == EXTENSION_CQF_CALCULATED_VALUE_URL }
+  return if (getValueString(this) != null) {
+    this
+  } else {
+    this.takeIf { hasExtension(EXTENSION_CQF_CALCULATED_VALUE_URL) }
+      ?.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 }
       }
       ?: this
-  } else {
-    this
   }
 }
+
+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() }
-  }
-}
+  )

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

@@ -18,9 +18,15 @@ package com.google.android.fhir.datacapture.validation
 
 import android.content.Context
 import com.google.android.fhir.datacapture.enablement.EnablementEvaluator
+import com.google.android.fhir.datacapture.extensions.EXTENSION_CQF_CALCULATED_VALUE_URL
+import com.google.android.fhir.datacapture.extensions.isFhirPath
 import com.google.android.fhir.datacapture.extensions.packRepeatedGroups
+import com.google.android.fhir.datacapture.fhirpath.ExpressionEvaluator
+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.QuestionnaireResponseItemComponent
 import org.hl7.fhir.r4.model.Resource
 import org.hl7.fhir.r4.model.Type
 
@@ -69,6 +75,13 @@ object QuestionnaireResponseValidator {
     }
 
     val linkIdToValidationResultMap = mutableMapOf<String, MutableList<ValidationResult>>()
+    val expressionEvaluator =
+      ExpressionEvaluator(
+        questionnaire,
+        questionnaireResponse,
+        questionnaireItemParentMap,
+        launchContextMap,
+      )
 
     validateQuestionnaireResponseItems(
       questionnaire.item,
@@ -80,17 +93,33 @@ object QuestionnaireResponseValidator {
         questionnaireItemParentMap,
         launchContextMap,
       ),
+      expressionEvaluator,
       linkIdToValidationResultMap,
     )
 
     return linkIdToValidationResultMap
   }
 
+  private fun ExpressionEvaluator.resolveCqfCalculatedValue(
+    questionnaireItem: QuestionnaireItemComponent,
+    questionnaireResponseItem: QuestionnaireResponseItemComponent,
+    expression: Expression,
+  ): Type? {
+    if (!expression.isFhirPath) {
+      throw UnsupportedOperationException("${expression.language} not supported yet")
+    }
+
+    return evaluateExpression(questionnaireItem, questionnaireResponseItem, expression)
+      .singleOrNull()
+      ?.let { it as Type }
+  }
+
   private fun validateQuestionnaireResponseItems(
     questionnaireItemList: List<Questionnaire.QuestionnaireItemComponent>,
     questionnaireResponseItemList: List<QuestionnaireResponse.QuestionnaireResponseItemComponent>,
     context: Context,
     enablementEvaluator: EnablementEvaluator,
+    expressionEvaluator: ExpressionEvaluator,
     linkIdToValidationResultMap: MutableMap<String, MutableList<ValidationResult>>,
   ): Map<String, List<ValidationResult>> {
     val questionnaireItemListIterator = questionnaireItemList.iterator()
@@ -113,11 +142,31 @@ object QuestionnaireResponseValidator {
         )
 
       if (enabled) {
+        // Evaluate cqf-calculatedValues
+        questionnaireItem.extension
+          .filter { it.hasValue() && it.value.hasExtension(EXTENSION_CQF_CALCULATED_VALUE_URL) }
+          .forEach { extension ->
+            val expression =
+              extension.value.getExtensionByUrl(EXTENSION_CQF_CALCULATED_VALUE_URL).value
+                as Expression
+            expressionEvaluator
+              .resolveCqfCalculatedValue(
+                questionnaireItem,
+                questionnaireResponseItem,
+                expression,
+              )
+              ?.let {
+                it.apply { setExtension(extension.value.extension) }
+                extension.setValue(it)
+              }
+          }
+
         validateQuestionnaireResponseItem(
           questionnaireItem,
           questionnaireResponseItem,
           context,
           enablementEvaluator,
+          expressionEvaluator,
           linkIdToValidationResultMap,
         )
       }
@@ -130,6 +179,7 @@ object QuestionnaireResponseValidator {
     questionnaireResponseItem: QuestionnaireResponse.QuestionnaireResponseItemComponent,
     context: Context,
     enablementEvaluator: EnablementEvaluator,
+    expressionEvaluator: ExpressionEvaluator,
     linkIdToValidationResultMap: MutableMap<String, MutableList<ValidationResult>>,
   ): Map<String, List<ValidationResult>> {
     when (checkNotNull(questionnaireItem.type) { "Questionnaire item must have type" }) {
@@ -143,6 +193,7 @@ object QuestionnaireResponseValidator {
           questionnaireResponseItem.item,
           context,
           enablementEvaluator,
+          expressionEvaluator,
           linkIdToValidationResultMap,
         )
       else -> {
@@ -156,6 +207,7 @@ object QuestionnaireResponseValidator {
             it.item,
             context,
             enablementEvaluator,
+            expressionEvaluator,
             linkIdToValidationResultMap,
           )
         }

datacapture/src/main/java/com/google/android/fhir/datacapture/views/QuestionnaireViewItem.kt

@@ -23,6 +23,8 @@ import com.google.android.fhir.datacapture.R
 import com.google.android.fhir.datacapture.extensions.displayString
 import com.google.android.fhir.datacapture.extensions.localizedTextSpanned
 import com.google.android.fhir.datacapture.extensions.toSpanned
+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.datacapture.validation.NotValidated
 import com.google.android.fhir.datacapture.validation.Valid
 import com.google.android.fhir.datacapture.validation.ValidationResult
@@ -52,12 +54,9 @@ import org.hl7.fhir.r4.model.QuestionnaireResponse
  * @param validationResult the [ValidationResult] of the answer(s) against the `questionnaireItem`
  * @param answersChangedCallback the callback to notify the view model that the answers have been
  *   changed for the [QuestionnaireResponse.QuestionnaireResponseItemComponent]
- * @param resolveAnswerValueSet the callback to resolve the answer value set and return the answer
- * @param resolveAnswerExpression the callback to resolve answer options when answer-expression
- *   extension exists options
+ *     @param enabledAnswerOptions the enabled answer options in [questionnaireItem]]
  * @param draftAnswer the draft input that cannot be stored in the [QuestionnaireResponse].
  * @param enabledDisplayItems the enabled display items in the given [questionnaireItem]
- * @param showOptionalText the optional text is being added to the end of the question text
  * @param questionViewTextConfiguration configuration to show asterisk, required and optional text
  *   in the header view.
  */
@@ -94,6 +93,10 @@ data class QuestionnaireViewItem(
   val answers: List<QuestionnaireResponse.QuestionnaireResponseItemAnswerComponent> =
     questionnaireResponseItem.answer.map { it.copy() }
 
+  val minValue by lazy { questionnaireItem.getExtensionByUrl(MIN_VALUE_EXTENSION_URL)?.value }
+
+  val maxValue by lazy { questionnaireItem.getExtensionByUrl(MAX_VALUE_EXTENSION_URL)?.value }
+
   /** Updates the answers. This will override any existing answers and removes the draft answer. */
   fun setAnswer(
     vararg questionnaireResponseItemAnswerComponent:

datacapture/src/main/java/com/google/android/fhir/datacapture/views/factories/DatePickerViewHolderFactory.kt

@@ -32,8 +32,6 @@ import com.google.android.fhir.datacapture.extensions.getValidationErrorMessage
 import com.google.android.fhir.datacapture.extensions.parseDate
 import com.google.android.fhir.datacapture.extensions.tryUnwrapContext
 import com.google.android.fhir.datacapture.validation.Invalid
-import com.google.android.fhir.datacapture.validation.MaxValueValidator.getMaxValue
-import com.google.android.fhir.datacapture.validation.MinValueValidator.getMinValue
 import com.google.android.fhir.datacapture.validation.ValidationResult
 import com.google.android.fhir.datacapture.views.HeaderView
 import com.google.android.fhir.datacapture.views.QuestionnaireViewItem
@@ -163,8 +161,8 @@ internal object DatePickerViewHolderFactory :
       }
 
       private fun getCalenderConstraint(): CalendarConstraints {
-        val min = (getMinValue(questionnaireViewItem.questionnaireItem) as? DateType)?.value?.time
-        val max = (getMaxValue(questionnaireViewItem.questionnaireItem) as? DateType)?.value?.time
+        val min = (questionnaireViewItem.minValue as? DateType)?.value?.time
+        val max = (questionnaireViewItem.maxValue as? DateType)?.value?.time
 
         if (min != null && max != null && min > max) {
           throw IllegalArgumentException("minValue cannot be greater than maxValue")