Add support for sliders (#63)

.swiftlint.yml

@@ -371,6 +371,9 @@ only_rules:
   # The variable should be placed on the left, the constant on the right of a comparison operator.
   - yoda_condition
 
+attributes:
+  attributes_with_arguments_always_on_line_above: false
+
 deployment_target: # Availability checks or attributes shouldn’t be using older versions that are satisfied by the deployment target.
   iOSApplicationExtension_deployment_target: 16.0
   iOS_deployment_target: 16.0

Example/ExampleApp/Responses/QuestionnaireResponseStorage.swift

@@ -11,8 +11,7 @@ import SwiftUI
 
 
 class QuestionnaireResponseStorage: ObservableObject {
-    @Published
-    private var responses: [URL: [QuestionnaireResponse]] = [:]
+    @Published private var responses: [URL: [QuestionnaireResponse]] = [:]
 
 
     func append(_ response: QuestionnaireResponse, for identifier: URL) {

Example/ExampleUITests/ExampleUITests.swift

@@ -6,6 +6,8 @@
 // SPDX-License-Identifier: MIT
 //
 
+// We disable file length because this is a test
+// swiftlint:disable file_length
 import XCTest
 
 // We disable type body length rule because this is a test
@@ -301,6 +303,36 @@ final class ExampleUITests: XCTestCase {
         app.swipeDown(velocity: XCUIGestureVelocity.fast)
     }
 
+    func testSliderExample() throws {
+        let app = XCUIApplication()
+        app.launch()
+
+        let sliderExampleButton = app.collectionViews.buttons["Slider Example"]
+
+        // Open questionnaire and start
+        sliderExampleButton.tap()
+
+        // Access the slider
+        let slider = app.sliders.firstMatch
+        XCTAssertTrue(slider.exists, "The slider does not exist")
+
+        // Calculate normalized position for the desired value
+        let desiredValue: CGFloat = 5
+        let sliderRange: CGFloat = 10
+        let normalizedPosition = desiredValue / sliderRange
+
+        // Adjust the slider's value
+        slider.adjust(toNormalizedSliderPosition: normalizedPosition)
+
+        // Check that the slider's value is now equal to the desired value
+        if let valueString = slider.value as? String, let value = Double(valueString) {
+            let sliderValue = CGFloat(value)
+            XCTAssertEqual(sliderValue, desiredValue, accuracy: 1)
+        } else {
+            XCTFail("Slider value is not a readable number.")
+        }
+    }
+
     // MARK: UI Tests for Clinical Questionnaires
 
     func testPHQ9Example() throws {

Package.swift

@@ -49,7 +49,8 @@ let package = Package(
                 .copy("Resources/IPSS.json"),
                 .copy("Resources/FormExample.json"),
                 .copy("Resources/MultipleEnableWhen.json"),
-                .copy("Resources/ImageCapture.json")
+                .copy("Resources/ImageCapture.json"),
+                .copy("Resources/SliderExample.json")
             ]
         ),
         .testTarget(

Sources/FHIRQuestionnaires/Questionnaire+Resources.swift

@@ -36,6 +36,9 @@ extension Questionnaire {
 
     /// A FHIR questionnaire demonstrating an image capture step
     public static var imageCaptureExample: Questionnaire = loadQuestionnaire(withName: "ImageCapture")
+
+    /// A FHIR questionnaire demonstrating a slider
+    public static var sliderExample: Questionnaire = loadQuestionnaire(withName: "SliderExample")
 
     /// A collection of example `Questionnaire`s provided by the FHIRQuestionnaires target to demonstrate functionality
     public static var exampleQuestionnaires: [Questionnaire] = [
@@ -46,7 +49,8 @@ extension Questionnaire {
         .dateTimeExample,
         .formExample,
         .multipleEnableWhen,
-        .imageCaptureExample
+        .imageCaptureExample,
+        .sliderExample
     ]
 
     // MARK: Examples of clinical research FHIR Questionnaires

Sources/FHIRQuestionnaires/Resources/SliderExample.json

@@ -0,0 +1,42 @@
+{
+  "resourceType": "Questionnaire",
+  "language": "en-US",
+  "id": "Stanford University-slider-example",
+  "title": "Slider Example",
+  "status": "draft",
+  "publisher": "Stanford University",
+  "url": "http://biodesign.stanford.edu/questionnaires/sliderexample",
+  "item": [
+    {
+      "linkId": "1",
+      "text": "How bad is the pain on a scale of 0-10?",
+      "type": "integer",
+      "extension": [
+        {
+          "url": "http://hl7.org/fhir/StructureDefinition/questionnaire-itemControl",
+          "valueCodeableConcept": {
+            "coding": [
+              {
+                "system": "http://hl7.org/fhir/questionnaire-item-control",
+                "code": "slider",
+                "display": "Slider"
+              }
+            ]
+          }
+        },
+        {
+          "url": "http://hl7.org/fhir/StructureDefinition/minValue",
+          "valueInteger": 0
+        },
+        {
+          "url": "http://hl7.org/fhir/StructureDefinition/maxValue",
+          "valueInteger": 10
+        },
+        {
+          "url": "http://hl7.org/fhir/StructureDefinition/questionnaire-sliderStepValue",
+          "valueInteger": 1
+        }
+      ]
+    }
+  ]
+}

Sources/FHIRQuestionnaires/Resources/SliderExample.json.license

@@ -0,0 +1,6 @@
+
+This source file is part of the ResearchKitOnFHIR open source project
+
+SPDX-FileCopyrightText: 2023 Stanford University and the project authors (see CONTRIBUTORS.md)
+
+SPDX-License-Identifier: MIT

Sources/ResearchKitOnFHIR/FHIRExtensions/FHIRExtensions.swift

@@ -13,8 +13,10 @@ import ModelsR4
 extension QuestionnaireItem {
     /// Supported FHIR extensions for QuestionnaireItems
     private enum SupportedExtensions {
+        static let itemControl = "http://hl7.org/fhir/StructureDefinition/questionnaire-itemControl"
         static let questionnaireUnit = "http://hl7.org/fhir/StructureDefinition/questionnaire-unit"
         static let regex = "http://hl7.org/fhir/StructureDefinition/regex"
+        static let sliderStepValue = "http://hl7.org/fhir/StructureDefinition/questionnaire-sliderStepValue"
         static let validationMessage = "http://biodesign.stanford.edu/fhir/StructureDefinition/validationtext"
         static let maxDecimalPlaces = "http://hl7.org/fhir/StructureDefinition/maxDecimalPlaces"
         static let minValue = "http://hl7.org/fhir/StructureDefinition/minValue"
@@ -33,6 +35,17 @@ extension QuestionnaireItem {
         }
         return isHidden
     }
+
+    /// Defines the control type for the answer for a question
+    /// - Returns: A code representing the control type (i.e. slider)
+    var itemControl: String? {
+        guard let itemControlExtension = getExtensionInQuestionnaireItem(url: SupportedExtensions.itemControl),
+              case let .codeableConcept(concept) = itemControlExtension.value,
+              let itemControlCode = concept.coding?.first?.code?.value?.string else {
+            return nil
+        }
+        return itemControlCode
+    }
 
     /// The minimum value for a numerical answer.
     /// - Returns: An optional `NSNumber` containing the minimum value allowed.
@@ -66,6 +79,17 @@ extension QuestionnaireItem {
         }
         return NSNumber(value: maxDecimalPlaces)
     }
+
+    /// The offset between numbers on a numerical slider
+    /// - Returns: An optional `NSNumber` representing the size of each discrete offset on the scale.
+    var sliderStepValue: NSNumber? {
+        guard let sliderStepValueExtension = getExtensionInQuestionnaireItem(url: SupportedExtensions.sliderStepValue),
+              case let .integer(integerValue) = sliderStepValueExtension.value,
+              let sliderStepValue = integerValue.value?.integer as? Int32 else {
+            return nil
+        }
+        return NSNumber(value: sliderStepValue)
+    }
 
     /// The unit of a quantity answer type.
     /// - Returns: An optional `String` containing the unit (i.e. cm) if it was provided.

Sources/ResearchKitOnFHIR/FHIRToResearchKit/QuestionnaireItem+ResearchKit.swift

@@ -142,7 +142,7 @@ extension QuestionnaireItem {
     /// - Returns: An object of type `ORKAnswerFormat` representing the type of answer this question accepts.
     private func toORKAnswerFormat(valueSets: [ValueSet]) throws -> ORKAnswerFormat {
         // swiftlint:disable:previous cyclomatic_complexity
-        // We have to cover all the switch cases in the following statement driving up the overal comlexity.
+        // We have to cover all the switch cases in the following statement driving up the overall complexity.
         switch type.value {
         case .boolean:
             return ORKBooleanAnswerFormat.booleanAnswerFormat()
@@ -165,6 +165,16 @@ extension QuestionnaireItem {
             answerFormat.maximum = maxValue
             return answerFormat
         case .integer:
+            if itemControl == "slider" {
+                let answerFormat = ORKScaleAnswerFormat(
+                    maximumValue: maxValue?.intValue ?? 0,
+                    minimumValue: minValue?.intValue ?? 0,
+                    defaultValue: minValue?.intValue ?? 0,
+                    step: Int(truncating: sliderStepValue ?? 1)
+                )
+                return answerFormat
+            }
+
             let answerFormat = ORKNumericAnswerFormat.integerAnswerFormat(withUnit: nil)
             answerFormat.minimum = minValue
             answerFormat.maximum = maxValue

Sources/ResearchKitOnFHIR/ResearchKitToFHIR/ORKTaskResult+FHIR.swift

@@ -52,16 +52,18 @@ extension ORKTaskResult {
             responseAnswer.value = createBooleanResponse(result)
         case let result as ORKChoiceQuestionResult:
             responseAnswer.value = createChoiceResponse(result)
+        case let result as ORKFileResult:
+            responseAnswer.value = createAttachmentResponse(result)
         case let result as ORKNumericQuestionResult:
             responseAnswer.value = createNumericResponse(result)
         case let result as ORKDateQuestionResult:
             responseAnswer.value = createDateResponse(result)
-        case let result as ORKTimeOfDayQuestionResult:
-            responseAnswer.value = createTimeResponse(result)
+        case let result as ORKScaleQuestionResult:
+            responseAnswer.value = createScaleResponse(result)
         case let result as ORKTextQuestionResult:
             responseAnswer.value = createTextResponse(result)
-        case let result as ORKFileResult:
-            responseAnswer.value = createAttachmentResponse(result)
+        case let result as ORKTimeOfDayQuestionResult:
+            responseAnswer.value = createTimeResponse(result)
         default:
             // Unsupported result type
             responseAnswer.value = nil
@@ -92,7 +94,15 @@ extension ORKTaskResult {
             return .decimal(FHIRPrimitive(FHIRDecimal(value.decimalValue)))
         }
     }
-
+
+    private func createScaleResponse(_ result: ORKScaleQuestionResult) -> QuestionnaireResponseItemAnswer.ValueX? {
+        guard let value = result.scaleAnswer else {
+            return nil
+        }
+
+        return .integer(FHIRPrimitive(FHIRInteger(value.int32Value)))
+    }
+
     private func createTextResponse(_ result: ORKTextQuestionResult) -> QuestionnaireResponseItemAnswer.ValueX? {
         guard let text = result.textAnswer else {
             return nil

Tests/ResearchKitOnFHIRTests/FHIRToResearchKitTests.swift

@@ -52,13 +52,25 @@ final class FHIRToResearchKitTests: XCTestCase {
         let valueSets = Questionnaire.containedValueSetExample.getContainedValueSets()
         XCTAssertEqual(valueSets.count, 1)
     }
+
+    func testItemControlExtension() throws {
+        let testItemControl = Questionnaire.sliderExample.item?.first?.itemControl
+        let itemControlValue = try XCTUnwrap(testItemControl)
+        XCTAssertEqual(itemControlValue, "slider")
+    }
 
     func testRegexExtension() throws {
         let testRegex = Questionnaire.textValidationExample.item?.first?.validationRegularExpression
         // swiftlint:disable:next line_length
         let regex = try NSRegularExpression(pattern: "^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$")
         XCTAssertEqual(regex, testRegex)
     }
+
+    func testSliderStepValueExtension() throws {
+        let testSliderStepValue = Questionnaire.sliderExample.item?.first?.sliderStepValue
+        let sliderStepValue = try XCTUnwrap(testSliderStepValue)
+        XCTAssertEqual(sliderStepValue, 1)
+    }
 
     func testValidationMessageExtension() throws {
         let testValidationMessage = Questionnaire.textValidationExample.item?.first?.validationMessage

Tests/ResearchKitOnFHIRTests/ResearchKitToFHIRTests.swift

@@ -98,6 +98,24 @@ final class ResearchKitToFHIRTests: XCTestCase {
         }
         XCTAssertEqual(testValue, responseValue)
     }
+
+    func testScaleResponse() {
+        let testValue = 1
+        var responseValue: Int?
+
+        let scaleResult = ORKScaleQuestionResult(identifier: "scaleResult")
+        scaleResult.scaleAnswer = testValue as NSNumber
+        let taskResult = createTaskResult(scaleResult)
+
+        let fhirResponse = taskResult.fhirResponse
+        let answer = fhirResponse.item?.first?.answer?.first?.value
+
+        if case let .integer(value) = answer,
+           let unwrappedValue = value.value?.integer {
+            responseValue = Int(unwrappedValue)
+        }
+        XCTAssertEqual(testValue, responseValue)
+    }
 
     func testQuantityResponse() {
         let testValue: Decimal = 1.5