data-export

# Data Export Generator Generate production data export and import infrastructure -- JSON export via Codable, CSV generation with proper escaping, PDF report rendering with UIGraphicsPDFRenderer, GDPR-compliant full data export, file import with UTType-based picker, and share sheet integration. No third-party dependencies. ## When This Skill Activates Use this skill when the user: - Asks to "add data export" or "export user data" - Wants "CSV export" or "JSON export" or "PDF export" - Mentions "GDPR data portability" or "right to data portability" - Asks about "exporting all user data" for compliance - Wants to "import data" from files or competitor apps - Mentions "share sheet" for exporting data - Asks about "data backup" or "data download" ## Pre-Generation Checks ### 1. Project Context Detection - [ ] Check deployment target (iOS 16+ / macOS 13+) - [ ] Check Swift version (requires Swift 5.9+) - [ ] Identify data model layer (SwiftData, Core Data, custom structs) - [ ] Identify source file locations ### 2. Existing Export Detection Search for existing export code: ``` Glob: **/*Export*.swift, **/*Import*.swift, **/*CSV*.swift, **/*PDF*.swift Grep: "UIGraphicsPDFRenderer" or "CSVExport" or "UIActivityViewController" or "ShareLink" or "fileExporter" ``` If existing export code found: - Ask if user wants to replace or add additional formats - Identify which formats are already supported ### 3. Data Model Detection Search for data models that need exporting: ``` Grep: "@Model" or "NSManagedObject" or "struct.*Codable" or "class.*Codable" ``` Identify the models to build export conformances for. ## Configuration Questions Ask user via AskUserQuestion: 1. **Export formats needed?** - JSON (structured, machine-readable, best for GDPR) - CSV (tabular data, spreadsheet-compatible) - PDF (formatted reports with headers, tables, branding) - Multiple (select which combination) 2. **What data needs exporting?** - All user data -- GDPR compliance (every piece of stored user data) - Specific data types (user selects which models to export) - Reports/summaries (aggregated data, not raw records) 3. **Do you need import capability?** - No -- export only - Yes -- from files (JSON, CSV via file picker) - Yes -- from competitor apps (custom format parsing) 4. **How should users trigger export?** - Share sheet (system share UI with multiple destinations) - Settings screen (dedicated export section) - Export button (inline in content views) - Automatic backup (periodic export to iCloud/local) ## Generation Process ### Step 1: Read Templates Read `templates.md` for production Swift code. ### Step 2: Create Core Files Generate these files: 1. `DataExportManager.swift` -- Central export coordinator with format routing 2. `DataExportable.swift` -- Protocol for models that support export ### Step 3: Create Format-Specific Files Based on configuration: 3. `CSVExporter.swift` -- If CSV format selected 4. `PDFExporter.swift` -- If PDF format selected ### Step 4: Create Import Files If import capability selected: 5. `DataImporter.swift` -- File picker and format parser ### Step 5: Determine File Location Check project structure: - If `Sources/` exists -> `Sources/DataExport/` - If `App/` exists -> `App/DataExport/` - Otherwise -> `DataExport/` ## Output Format After generation, provide: ### Files Created ``` DataExport/ ├── DataExportable.swift # Protocol for exportable models ├── DataExportManager.swift # Central export coordinator ├── CSVExporter.swift # CSV generation (optional) ├── PDFExporter.swift # PDF rendering (optional) └── DataImporter.swift # File import (optional) ``` ### Integration with Data Models **Make a model exportable:** ```swift struct Expense: Codable, DataExportable { let id: UUID let title: String let amount: Double let date: Date let category: String // DataExportable conformance static var csvHeaders: [String] { ["ID", "Title", "Amount", "Date", "Category"] } var csvRow: [String] { [id.uuidString, title, String(format: "%.2f", amount), ISO8601DateFormatter().string(from: date), category] } var pdfDescription: String { "\(title) - $\(String(format: "%.2f", amount)) (\(category))" } } ``` **Export from a view:** ```swift struct ExpenseListView: View { let expenses: [Expense] @State private var exportURL: URL? @State private var showShareSheet = false var body: some View { List(expenses) { expense in ExpenseRow(expense: expense) } .toolbar { Menu { Button("Export as JSON") { Task { await exportAs(.json) } } Button("Export as CSV") { Task { await exportAs(.csv) } } Button("Export as PDF") { Task { await exportAs(.pdf) } } } label: { Label("Export", systemImage: "square.and.arrow.up") } } .sheet(isPresented: $showShareSheet) { if let exportURL { ShareSheet(activityItems: [exportURL]) } } } private func exportAs(_ format: DataExportManager.ExportFormat) async { do { exportURL = try await DataExportManager.shared.export( expenses, format: format, filename: "expenses" ) showShareSheet = true } catch { // Handle error } } } ``` **SwiftUI ShareLink (iOS 16+):** ```swift if let url = exportURL { ShareLink(item: url) { Label("Share Export", systemImage: "square.and.arrow.up") } } ``` **Import from file picker:** ```swift struct ImportView: View { @State private var showFilePicker = false @State private var importedItems: [Expense] = [] var body: some View { Button("Import Data") { showFilePicker = true } .fileImporter( isPresented: $showFilePicker, allowedContentTypes: DataImporter.supportedTypes ) { result in Task { let url = try result.get() importedItems = try await DataImporter.importFile( from: url, as: Expense.self ) } } } } ``` ### GDPR Data Portability For full GDPR compliance, export ALL user data: ```swift func exportAllUserData() async throws -> URL { let allData = GDPRExportData( profile: try await fetchUserProfile(), expenses: try await fetchAllExpenses(), settings: try await fetchUserSettings(), exportDate: Date(), appVersion: Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String ?? "1.0" ) let encoder = JSONEncoder() encoder.outputFormatting = [.prettyPrinted, .sortedKeys] encoder.dateEncodingStrategy = .iso8601 let data = try encoder.encode(allData) let url = FileManager.default.temporaryDirectory .appendingPathComponent("user-data-export.json") try data.write(to: url) return url } ``` ### Testing ```swift @Test func jsonExportRoundTrip() async throws { let expenses = [ Expense(id: UUID(), title: "Coffee", amount: 4.50, date: Date(), category: "Food") ] let url = try await DataExportManager.shared.export( expenses, format: .json, filename: "test" ) let data = try Data(contentsOf: url) let decoded = try JSONDecoder().decode([Expense].self, from: data) #expect(decoded.count == 1) #expect(decoded.first?.title == "Coffee") } @Test func csvExportFormatsCorrectly() { let expenses = [ Expense(id: UUID(), title: "Coffee, Large", amount: 4.50, date: Date(), category: "Food") ] let csv = CSVExporter.generate( from: expenses, headers: Expense.csvHeaders, rowMapper: { $0.csvRow } ) #expect(csv.contains("\"Coffee, Large\"")) // Commas escaped with quotes #expect(csv.hasPrefix("ID,Title,Amount,Date,Category")) } @Test func importParsesCSV() async throws { let csvContent = "ID,Title,Amount\n1,Coffee,4.50\n2,Lunch,12.00" let url = FileManager.default.temporaryDirectory.appendingPathComponent("test.csv") try csvContent.write(to: url, atomically: true, encoding: .utf8) let rows = try CSVExporter.parse(from: url) #expect(rows.count == 2) #expect(rows.first?["Title"] == "Coffee") } ``` ## Common Patterns ### Export to Temporary File for Sharing Always export to a temporary directory, then present via share sheet: ```swift let url = FileManager.default.temporaryDirectory .appendingPathComponent("export.\(format.fileExtension)") try data.write(to: url) // Present via UIActivityViewController or ShareLink ``` ### GDPR Export Should Include Everything For GDPR Article 20 compliance, export must include: - All personal data the user provided - All data generated about the user - With clear field descriptions ### CSV Must Handle Special Characters Wrap fields containing commas, quotes, or newlines in double quotes; escape internal quotes by doubling them. ## Gotchas ### Temporary Files Cleanup Delete large export files after sharing completes rather than relying on the system's periodic cleanup. ### PDF Rendering on Background Thread `UIGraphicsPDFRenderer` must be used on the main thread if it references UIKit views. For data-only PDF generation (text, lines, rectangles), it is safe to render on a background thread. ### Large Dataset Memory For exporting thousands of records, stream the output instead of building the entire string/data in memory. Write CSV line-by-line to a file handle. For JSON, use JSONSerialization with streams. ### ShareLink vs UIActivityViewController Use `ShareLink` for the simple case; use `UIActivityViewController` when you need excluded activities, completion handlers, or custom activities. ### File Import Security Scoped URLs `.fileImporter` URLs are security-scoped: call `url.startAccessingSecurityScopedResource()` before reading, `url.stopAccessingSecurityScopedResource()` after. ## References - **templates.md** -- All production Swift templates for data export/import - [UIGraphicsPDFRenderer](https://developer.apple.com/documentation/uikit/uigraphicspdfrenderer) - [UIActivityViewController](https://developer.apple.com/documentation/uikit/uiactivityviewcontroller) - [UniformTypeIdentifiers](https://developer.apple.com/documentation/uniformtypeidentifiers) - [GDPR Article 20 - Right to Data Portability](https://gdpr-info.eu/art-20-gdpr/) - Related: `generators/settings-screen` -- Settings screen with export button - Related: `generators/account-deletion` -- Account deletion includes data export option