Added algorithm for pagination to PDF export, allowing to export consent forms with more than 1 page (#49)

.github/workflows/build-and-test.yml

@@ -85,15 +85,6 @@ jobs:
   buildandtestuitests_ios:
     name: Build and Test UI Tests iOS
     uses: StanfordSpezi/.github/.github/workflows/xcodebuild-or-fastlane.yml@v2
-    strategy:
-      matrix:
-        include:
-          - buildConfig: Debug
-            resultBundle: TestApp-iOS.xcresult
-            artifactname: TestApp-iOS.xcresult
-          - buildConfig: Release
-            resultBundle: TestApp-iOS-Release.xcresult
-            artifactname: TestApp-iOS-Release.xcresult
     with:
       runsonlabels: '["macOS", "self-hosted"]'
       path: 'Tests/UITests'
@@ -125,23 +116,13 @@ jobs:
   buildandtestuitests_visionos:
     name: Build and Test UI Tests visionOS
     uses: StanfordSpezi/.github/.github/workflows/xcodebuild-or-fastlane.yml@v2
-    strategy:
-      matrix:
-        include:
-          - buildConfig: Debug
-            resultBundle: TestApp-visionOS.xcresult
-            artifactname: TestApp-visionOS.xcresult
-          - buildConfig: Release
-            resultBundle: TestApp-visionOS-Release.xcresult
-            artifactname: TestApp-visionOS-Release.xcresult
     with:
       runsonlabels: '["macOS", "self-hosted"]'
       path: 'Tests/UITests'
       scheme: TestApp
       destination: 'platform=visionOS Simulator,name=Apple Vision Pro'
-      buildConfig: ${{ matrix.buildConfig }}
-      resultBundle: ${{ matrix.resultBundle }}
-      artifactname: ${{ matrix.artifactname }}
+      resultBundle: TestApp-visionOS.xcresult
+      artifactname: TestApp-visionOS.xcresult
   uploadcoveragereport:
     name: Upload Coverage Report
     needs: [buildandtest_ios, buildandtest_visionos, buildandtest_macos, buildandtestuitests_ios, buildandtestuitests_ipad, buildandtestuitests_visionos]

Package.swift

@@ -2,9 +2,9 @@
 
 //
 // This source file is part of the Stanford Spezi open-source project
-// 
+//
 // SPDX-FileCopyrightText: 2022 Stanford University and the project authors (see CONTRIBUTORS.md)
-// 
+//
 // SPDX-License-Identifier: MIT
 //
 
@@ -33,7 +33,8 @@ let package = Package(
     dependencies: [
         .package(url: "https://github.com/StanfordSpezi/Spezi", from: "1.2.1"),
         .package(url: "https://github.com/StanfordSpezi/SpeziViews", from: "1.3.1"),
-        .package(url: "https://github.com/apple/swift-collections.git", from: "1.1.0")
+        .package(url: "https://github.com/apple/swift-collections.git", from: "1.1.0"),
+        .package(url: "https://github.com/techprimate/TPPDF", from: "2.6.0")
     ] + swiftLintPackage(),
     targets: [
         .target(
@@ -42,7 +43,8 @@ let package = Package(
                 .product(name: "Spezi", package: "Spezi"),
                 .product(name: "SpeziViews", package: "SpeziViews"),
                 .product(name: "SpeziPersonalInfo", package: "SpeziViews"),
-                .product(name: "OrderedCollections", package: "swift-collections")
+                .product(name: "OrderedCollections", package: "swift-collections"),
+                .product(name: "TPPDF", package: "TPPDF")
             ],
             swiftSettings: [
                 swiftConcurrency
@@ -54,6 +56,9 @@ let package = Package(
             dependencies: [
                 .target(name: "SpeziOnboarding")
             ],
+            resources: [
+                .process("Resources/")
+            ],
             swiftSettings: [
                 swiftConcurrency
             ],

Sources/SpeziOnboarding/ConsentView/ConsentDocument+Export.swift

@@ -9,7 +9,7 @@
 import PDFKit
 import PencilKit
 import SwiftUI
-
+import TPPDF
 
 /// Extension of `ConsentDocument` enabling the export of the signed consent page.
 extension ConsentDocument {
@@ -18,7 +18,7 @@ extension ConsentDocument {
     /// force the ink used in the `UIImage` of the `PKDrawing` to always be black by adjusting the signature ink according to the color scheme.
     @MainActor private var blackInkSignatureImage: UIImage {
         var updatedDrawing = PKDrawing()
-        
+
         for stroke in signature.strokes {
             let blackStroke = PKStroke(
                 ink: PKInk(stroke.ink.inkType, color: colorScheme == .light ? .black : .white),
@@ -43,101 +43,21 @@ extension ConsentDocument {
     }
     #endif
 
-
-    /// Creates a representation of the consent form that is ready to be exported via the SwiftUI `ImageRenderer`.
-    ///
-    /// - Parameters:
-    ///   - markdown: The markdown consent content as an `AttributedString`.
-    ///
-    /// - Returns: A SwiftUI `View` representation of the consent content and signature.
-    ///
-    /// - Note: This function avoids the use of asynchronous operations.
-    /// Asynchronous tasks are incompatible with SwiftUI's `ImageRenderer`,
-    /// which expects all rendering processes to be synchronous.
-    @MainActor
-    private func exportBody(markdown: AttributedString) -> some View {
-        VStack {
-            if exportConfiguration.includingTimestamp {
-                HStack {
-                    Spacer()
-
-                    Text("EXPORTED_TAG", bundle: .module)
-                        + Text(verbatim: ": \(DateFormatter.localizedString(from: Date(), dateStyle: .medium, timeStyle: .short))")
-                }
-                .font(.caption)
-                .padding()
-            }
-
-            OnboardingTitleView(title: exportConfiguration.consentTitle)
-
-            Text(markdown)
-                .padding()
-
-            Spacer()
-
-            ZStack(alignment: .bottomLeading) {
-                SignatureViewBackground(name: name, backgroundColor: .clear)
-
-                #if !os(macOS)
-                Image(uiImage: blackInkSignatureImage)
-                #else
-                Text(signature)
-                    .padding(.bottom, 32)
-                    .padding(.leading, 46)
-                    .font(.custom("Snell Roundhand", size: 24))
-                #endif
-            }
-                #if !os(macOS)
-                .frame(width: signatureSize.width, height: signatureSize.height)
-                #else
-                .padding(.horizontal, 100)
-                #endif
-        }
-    }
-
-    /// Exports the signed consent form as a `PDFDocument` via the SwiftUI `ImageRenderer`.
-    ///
+    /// Exports the signed consent form as a `PDFKit.PDFDocument`.
+    /// The PDF generated by TPPDF and then converted to a TPDFKit.PDFDocument.
     /// Renders the `PDFDocument` according to the specified ``ConsentDocument/ExportConfiguration``.
     ///
     /// - Returns: The exported consent form in PDF format as a PDFKit `PDFDocument`
     @MainActor
-    func export() async -> PDFDocument? {
-        let markdown = await asyncMarkdown()
-
-        let markdownString = (try? AttributedString(
-            markdown: markdown,
-            options: .init(interpretedSyntax: .inlineOnlyPreservingWhitespace)
-        )) ?? AttributedString(String(localized: "MARKDOWN_LOADING_ERROR", bundle: .module))
-
-        let renderer = ImageRenderer(content: exportBody(markdown: markdownString))
-        let paperSize = CGSize(
-            width: exportConfiguration.paperSize.dimensions.width,
-            height: exportConfiguration.paperSize.dimensions.height
+    func export() async -> PDFKit.PDFDocument? {
+        let personName = name.formatted(.name(style: .long))
+
+        #if !os(macOS)
+        return await viewModel.export(
+            personName: personName, signatureImage: blackInkSignatureImage
         )
-        renderer.proposedSize = .init(paperSize)
-
-        return await withCheckedContinuation { continuation in
-            renderer.render { _, context in
-                var box = CGRect(origin: .zero, size: paperSize)
-
-                /// Create in-memory `CGContext` that stores the PDF
-                guard let mutableData = CFDataCreateMutable(kCFAllocatorDefault, 0),
-                      let consumer = CGDataConsumer(data: mutableData),
-                      let pdf = CGContext(consumer: consumer, mediaBox: &box, nil) else {
-                    continuation.resume(returning: nil)
-                    return
-                }
-
-                pdf.beginPDFPage(nil)
-                pdf.translateBy(x: 0, y: 0)
-
-                context(pdf)
-
-                pdf.endPDFPage()
-                pdf.closePDF()
-
-                continuation.resume(returning: PDFDocument(data: mutableData as Data))
-            }
-        }
+        #else
+        return await viewModel.export(personName: personName, signature: signature)
+        #endif
     }
 }

Sources/SpeziOnboarding/ConsentView/ConsentDocument.swift

@@ -41,12 +41,12 @@ public struct ConsentDocument: View {
     /// The maximum width such that the drawing canvas fits onto the PDF.
     static let maxWidthDrawing: CGFloat = 550
 
-    let asyncMarkdown: () async -> Data
     private let givenNameTitle: LocalizedStringResource
     private let givenNamePlaceholder: LocalizedStringResource
     private let familyNameTitle: LocalizedStringResource
     private let familyNamePlaceholder: LocalizedStringResource
-    let exportConfiguration: ExportConfiguration
+
+    let viewModel: ConsentDocumentModel
 
     @Environment(\.colorScheme) var colorScheme
     @State var name = PersonNameComponents()
@@ -134,7 +134,7 @@ public struct ConsentDocument: View {
 
     public var body: some View {
         VStack {
-            MarkdownView(asyncMarkdown: asyncMarkdown, state: $viewState.base)
+            MarkdownView(asyncMarkdown: viewModel.asyncMarkdown, state: $viewState.base)
             Spacer()
             Group {
                 nameView
@@ -203,13 +203,16 @@ public struct ConsentDocument: View {
         familyNamePlaceholder: LocalizedStringResource = LocalizationDefaults.familyNamePlaceholder,
         exportConfiguration: ExportConfiguration = .init()
     ) {
-        self.asyncMarkdown = markdown
         self._viewState = viewState
         self.givenNameTitle = givenNameTitle
         self.givenNamePlaceholder = givenNamePlaceholder
         self.familyNameTitle = familyNameTitle
         self.familyNamePlaceholder = familyNamePlaceholder
-        self.exportConfiguration = exportConfiguration
+
+        self.viewModel = ConsentDocumentModel(
+            markdown: markdown,
+            exportConfiguration: exportConfiguration
+        )
     }
 }