Cqf expression implementation for dynamic question title

catalog/src/main/assets/behavior_dynamic_question_title.json

@@ -0,0 +1,68 @@
+{
+  "resourceType": "Questionnaire",
+  "item": [
+    {
+      "text": "Choose vaccination administered",
+      "type": "choice",
+      "extension": [
+        {
+          "url": "http://hl7.org/fhir/StructureDefinition/questionnaire-itemControl",
+          "valueCodeableConcept": {
+            "coding": [
+              {
+                "system": "http://hl7.org/fhir/questionnaire-item-control",
+                "code": "radio-button",
+                "display": "Radio Button"
+              }
+            ]
+          }
+        }
+      ],
+      "linkId": "1",
+      "required": true,
+      "answerOption": [
+        {
+          "valueCoding": {
+            "code": "bcg",
+            "display": "BCG - Bacillus Calmette Guerin Vaccine"
+          }
+        },
+        {
+          "valueCoding": {
+            "code": "opv 0",
+            "display": "OPV 0 - Oral Poliovirus Vaccine"
+          }
+        },
+        {
+          "valueCoding": {
+            "code": "penta 1",
+            "display": "Penta 1 - Pentavalent (DPT + Hep B + Hib) Vaccine"
+          }
+        },
+        {
+          "valueCoding": {
+            "code": "pcv 1",
+            "display": "PCV 1 - Pneumococcal Conjugate Vaccine"
+          }
+        }
+      ]
+    },
+    {
+      "linkId": "2",
+      "required": true,
+      "text": "Vaccine Date",
+      "_text": {
+        "extension": [
+          {
+            "url": "http://hl7.org/fhir/StructureDefinition/cqf-expression",
+            "valueExpression": {
+              "language": "text/fhirpath",
+              "expression": "'Select '+ %resource.descendants().where(linkId = '1').answer.value.display + ' Date'"
+            }
+          }
+        ]
+      },
+      "type": "date"
+    }
+  ]
+}

catalog/src/main/java/com/google/android/fhir/catalog/BehaviorListViewModel.kt

@@ -42,6 +42,11 @@ class BehaviorListViewModel(application: Application) : AndroidViewModel(applica
       R.drawable.ic_skiplogic_behavior,
       R.string.behavior_name_skip_logic,
       "behavior_skip_logic.json"
+    ),
+    DYNAMIC_QUESTION_TITLE(
+      R.drawable.ic_dynamic_title_behavior,
+      R.string.behavior_name_dynamic_question_title,
+      "behavior_dynamic_question_title.json"
     )
   }
 }

catalog/src/main/res/drawable/ic_dynamic_title_behavior.xml

@@ -0,0 +1,30 @@
+<vector
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="194dp"
+    android:height="128dp"
+    android:viewportWidth="194"
+    android:viewportHeight="128"
+>
+  <path
+        android:strokeWidth="1"
+        android:pathData="M135.5,27V101C135.5,101.828 134.828,102.5 134,102.5H60C59.172,102.5 58.5,101.828 58.5,101V27C58.5,26.172 59.172,25.5 60,25.5H97H134C134.828,25.5 135.5,26.172 135.5,27Z"
+        android:fillColor="#ffffff"
+        android:strokeColor="#8AB4F8"
+    />
+  <path
+        android:pathData="M64,49C64,43.477 68.477,39 74,39L135,39V59L74,59C68.477,59 64,54.523 64,49V49Z"
+        android:fillColor="#D2E3FC"
+    />
+  <path
+        android:pathData="M74,49m-10,0a10,10 0,1 1,20 0a10,10 0,1 1,-20 0"
+        android:fillColor="#1A73E8"
+    />
+  <path
+        android:pathData="M125,79C125,84.523 120.523,89 115,89L59,89L59,69L115,69C120.523,69 125,73.477 125,79V79Z"
+        android:fillColor="#D2E3FC"
+    />
+  <path
+        android:pathData="M115,79m-10,0a10,10 0,1 1,20 0a10,10 0,1 1,-20 0"
+        android:fillColor="#1A73E8"
+    />
+</vector>

catalog/src/main/res/values/strings.xml

@@ -43,6 +43,9 @@
     <string
         name="behavior_name_skip_logic_info"
     >If Yes is selected, a follow-up question is displayed. If No is selected, no follow-up questions are displayed.</string>
+    <string
+        name="behavior_name_dynamic_question_title"
+    >Dynamic Question Title</string>
     <string
         name="behavior_name_calculated_expression_info"
     >Input age to automatically calculate birthdate until birthdate is updated manually.</string>

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

@@ -31,6 +31,7 @@ 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.answerExpression
+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.extractAnswerOptions
@@ -49,6 +50,7 @@ import com.google.android.fhir.datacapture.extensions.validateLaunchContext
 import com.google.android.fhir.datacapture.fhirpath.ExpressionEvaluator
 import com.google.android.fhir.datacapture.fhirpath.ExpressionEvaluator.detectExpressionCyclicDependency
 import com.google.android.fhir.datacapture.fhirpath.ExpressionEvaluator.evaluateCalculatedExpressions
+import com.google.android.fhir.datacapture.fhirpath.evaluateToBase
 import com.google.android.fhir.datacapture.fhirpath.fhirPathEngine
 import com.google.android.fhir.datacapture.validation.Invalid
 import com.google.android.fhir.datacapture.validation.NotValidated
@@ -64,7 +66,9 @@ import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.flow.update
+import org.hl7.fhir.r4.model.Base
 import org.hl7.fhir.r4.model.Coding
+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
@@ -533,6 +537,20 @@ internal class QuestionnaireViewModel(application: Application, state: SavedStat
     return options
   }
 
+  internal fun resolveCqfExpression(
+    questionnaireResponseItem: QuestionnaireResponseItemComponent,
+    element: Element,
+  ): List<Base> {
+    val cqfExpression = element.cqfExpression ?: return emptyList()
+    if (cqfExpression.isFhirPath) {
+      return evaluateToBase(
+        questionnaireResponse,
+        questionnaireResponseItem,
+        cqfExpression.expression
+      )
+    } else throw UnsupportedOperationException("${cqfExpression.language} not supported yet")
+  }
+
   private suspend fun loadAnswerExpressionOptions(
     item: QuestionnaireItemComponent,
     expression: Expression,
@@ -685,6 +703,7 @@ internal class QuestionnaireViewModel(application: Application, state: SavedStat
             answersChangedCallback = answersChangedCallback,
             resolveAnswerValueSet = { resolveAnswerValueSet(it) },
             resolveAnswerExpression = { resolveAnswerExpression(it) },
+            resolveCqfExpression = { resolveCqfExpression(questionnaireResponseItem, it) },
             draftAnswer = draftAnswerMap[questionnaireResponseItem],
             enabledDisplayItems =
               questionnaireItem.item.filter {

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

@@ -16,7 +16,18 @@
 
 package com.google.android.fhir.datacapture.extensions
 
+import org.hl7.fhir.r4.model.Element
 import org.hl7.fhir.r4.model.Expression
+import org.hl7.fhir.r4.utils.ToolingExtensions
+
+internal const val EXTENSION_CQF_EXPRESSION_URL: String =
+  "http://hl7.org/fhir/StructureDefinition/cqf-expression"
+
+internal val Element.cqfExpression: Expression?
+  get() =
+    ToolingExtensions.getExtension(this, EXTENSION_CQF_EXPRESSION_URL)?.value?.let {
+      it.castToExpression(it)
+    }
 
 internal val Expression.isXFhirQuery: Boolean
   get() = this.language == Expression.ExpressionLanguage.APPLICATION_XFHIRQUERY.toCode()

datacapture/src/main/java/com/google/android/fhir/datacapture/fhirpath/FhirPathUtil.kt

@@ -19,6 +19,8 @@ package com.google.android.fhir.datacapture.fhirpath
 import ca.uhn.fhir.context.FhirContext
 import ca.uhn.fhir.context.FhirVersionEnum
 import org.hl7.fhir.r4.hapi.ctx.HapiWorkerContext
+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.utils.FHIRPathEngine
 
@@ -34,3 +36,22 @@ internal val fhirPathEngine: FHIRPathEngine =
  */
 internal fun evaluateToDisplay(expressions: List<String>, data: Resource) =
   expressions.joinToString(" ") { fhirPathEngine.evaluateToString(data, it) }
+
+/**
+ * Evaluates the expressions over list of resources [QuestionnaireResponse] and
+ * [QuestionnaireResponseItemComponent] and returns the resulting elements FhirPath supplements
+ * https://build.fhir.org/ig/HL7/sdc/expressions.html#fhirpath-supplements %resource =
+ * [QuestionnaireResponse] %context = [QuestionnaireResponseItemComponent]
+ */
+internal fun evaluateToBase(
+  questionnaireResponse: QuestionnaireResponse,
+  questionnaireResponseItemComponent: QuestionnaireResponseItemComponent,
+  expression: String
+) =
+  fhirPathEngine.evaluate(
+    null,
+    questionnaireResponse,
+    null,
+    questionnaireResponseItemComponent,
+    expression
+  )

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

@@ -26,7 +26,6 @@ import com.google.android.fhir.datacapture.extensions.getHeaderViewVisibility
 import com.google.android.fhir.datacapture.extensions.initHelpViews
 import com.google.android.fhir.datacapture.extensions.localizedInstructionsSpanned
 import com.google.android.fhir.datacapture.extensions.localizedPrefixSpanned
-import com.google.android.fhir.datacapture.extensions.localizedTextSpanned
 import com.google.android.fhir.datacapture.extensions.updateTextAndVisibility
 
 /** View for the prefix, question, and hint of a questionnaire item. */
@@ -49,7 +48,7 @@ internal class HeaderView(context: Context, attrs: AttributeSet?) : LinearLayout
       questionnaireItem = questionnaireViewItem.questionnaireItem
     )
     prefix.updateTextAndVisibility(questionnaireViewItem.questionnaireItem.localizedPrefixSpanned)
-    question.updateTextAndVisibility(questionnaireViewItem.questionnaireItem.localizedTextSpanned)
+    question.updateTextAndVisibility(questionnaireViewItem.questionTitle)
     hint.updateTextAndVisibility(
       questionnaireViewItem.enabledDisplayItems.localizedInstructionsSpanned
     )

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

@@ -17,15 +17,21 @@
 package com.google.android.fhir.datacapture.views
 
 import android.content.Context
+import android.text.Spanned
+import androidx.core.text.toSpanned
 import androidx.recyclerview.widget.RecyclerView
 import com.google.android.fhir.datacapture.R
 import com.google.android.fhir.datacapture.extensions.answerExpression
+import com.google.android.fhir.datacapture.extensions.cqfExpression
 import com.google.android.fhir.datacapture.extensions.displayString
+import com.google.android.fhir.datacapture.extensions.localizedTextSpanned
 import com.google.android.fhir.datacapture.validation.NotValidated
 import com.google.android.fhir.datacapture.validation.Valid
 import com.google.android.fhir.datacapture.validation.ValidationResult
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.runBlocking
+import org.hl7.fhir.r4.model.Base
+import org.hl7.fhir.r4.model.Element
 import org.hl7.fhir.r4.model.Questionnaire
 import org.hl7.fhir.r4.model.QuestionnaireResponse
 
@@ -80,6 +86,7 @@ data class QuestionnaireViewItem(
     {
       emptyList()
     },
+  private val resolveCqfExpression: (Element) -> List<Base> = { emptyList() },
   internal val draftAnswer: Any? = null,
   internal val enabledDisplayItems: List<Questionnaire.QuestionnaireItemComponent> = emptyList()
 ) {
@@ -199,6 +206,18 @@ data class QuestionnaireViewItem(
         }
       }
 
+  /**
+   * Fetches the question title that should be displayed to user. The title is evaluated from
+   * cqf-expression on textElement if exists, otherwise it is derived from translatable textElement
+   * property
+   */
+  internal val questionTitle: Spanned? by lazy {
+    questionnaireItem.textElement
+      .takeIf { it.cqfExpression != null }
+      ?.let { resolveCqfExpression(it).firstOrNull()?.primitiveValue()?.toSpanned() }
+      ?: questionnaireItem.localizedTextSpanned
+  }
+
   /**
    * Returns whether this [QuestionnaireViewItem] and the `other` [QuestionnaireViewItem] have the
    * same [Questionnaire.QuestionnaireItemComponent] and
@@ -210,7 +229,8 @@ data class QuestionnaireViewItem(
    */
   internal fun hasTheSameItem(other: QuestionnaireViewItem) =
     questionnaireItem === other.questionnaireItem &&
-      questionnaireResponseItem === other.questionnaireResponseItem
+      questionnaireResponseItem === other.questionnaireResponseItem &&
+      questionTitle == other.questionTitle
 
   /**
    * Returns whether this [QuestionnaireViewItem] and the `other` [QuestionnaireViewItem] have the