Agent Skills: Share Card Generator

Share Card Generator

Generate a production share card system that renders app content (achievements, statistics, quotes, milestones) as shareable images with SwiftUI ImageRenderer, customizable styles, optional QR code overlays, and native ShareLink integration.

When This Skill Activates

Use this skill when the user:

• Asks to "generate share cards" or "create shareable images"
• Wants to "share achievements as images" or "share stats to social media"
• Mentions "social media cards" or "shareable content cards"
• Asks about "exporting content as images" or "screenshot sharing"
• Wants "branded share images" or "share card templates"
• Asks to "add ShareLink with image" or "share rendered SwiftUI view"
• Wants "QR code on share image" or "deep link in share card"

Pre-Generation Checks

1. Project Context Detection

• [ ] Check Swift version (requires Swift 5.9+)
• [ ] Check deployment target (iOS 16+ / macOS 13+ minimum for ImageRenderer)
• [ ] Check for @Observable support (iOS 17+ / macOS 14+)
• [ ] Identify source file locations

2. Conflict Detection

Search for existing share/export code:

Glob: **/*ShareCard*.swift, **/*ShareImage*.swift, **/*SocialCard*.swift
Grep: "ImageRenderer" or "ShareLink" or "UIGraphicsImageRenderer" or "share.*image"

If existing share infrastructure found:

• Ask if user wants to replace or extend it
• If extending, integrate with existing models and styles

3. Platform Detection

Determine if generating for iOS (UIImage) or macOS (NSImage) or both (cross-platform PlatformImage typealias).

Configuration Questions

Ask user via AskUserQuestion:

1. Card style?

   • Minimal (clean, text-focused, light/dark adaptive)
   • Branded (app logo, brand colors, custom typography)
   • Statistics (data-heavy with charts/numbers emphasis)

2. Share destinations?

   • Social media (Instagram, Twitter/X — optimized aspect ratios)
   • Messages / General sharing (flexible sizing)
   • Both — recommended

3. Card size preset?

   • Square (1080x1080 — Instagram, general purpose)
   • Story (1080x1920 — Instagram Stories, TikTok)
   • Wide (1200x630 — Twitter/X, Open Graph)
   • Custom (user-specified dimensions)

4. Include QR code?

   • Yes (deep link or App Store URL embedded in card corner)
   • No (cleaner card, no link)

5. Content types? (multi-select)

   • Achievements / Milestones
   • Statistics / Progress
   • Quotes / Text content
   • Custom (user defines their own content model)

Generation Process

Step 1: Read Templates

Read templates.md for production Swift code.

Step 2: Create Core Files

Generate these files:

1. ShareCardContent.swift — Protocol and concrete content types (achievement, statistics, quote)
2. ShareCardStyle.swift — Enum with predefined styles, colors, fonts, layout configuration
3. ShareCardRenderer.swift — @MainActor renderer using ImageRenderer to convert SwiftUI views to images
4. ShareCardView.swift — The SwiftUI view that composes the card layout (background, content, branding)

Step 3: Create UI Files

5. ShareCardSheet.swift — Complete sharing sheet with style picker, live preview, and ShareLink

Step 4: Create Optional Files

Based on configuration:

• QRCodeOverlay.swift — If QR code selected (CoreImage-based QR generator)
• ShareCardPreview.swift — SwiftUI Preview helpers for design iteration

Step 5: Determine File Location

Check project structure:

• If Sources/ exists -> Sources/ShareCard/
• If App/ exists -> App/ShareCard/
• Otherwise -> ShareCard/

Output Format

After generation, provide:

Files Created

ShareCard/
├── ShareCardContent.swift    # Protocol + concrete content types
├── ShareCardStyle.swift      # Style enum with colors, fonts, layout
├── ShareCardRenderer.swift   # ImageRenderer-based rendering
├── ShareCardView.swift       # Card layout SwiftUI view
├── ShareCardSheet.swift      # Share sheet with preview + ShareLink
├── QRCodeOverlay.swift       # CoreImage QR code (optional)
└── ShareCardPreview.swift    # Preview helpers (optional)

Integration Steps

Share an achievement:

struct AchievementDetailView: View {
    let achievement: Achievement
    @State private var showShareCard = false

    var body: some View {
        VStack {
            // ... achievement detail content ...

            Button("Share Achievement") {
                showShareCard = true
            }
        }
        .sheet(isPresented: $showShareCard) {
            ShareCardSheet(
                content: AchievementCardContent(
                    title: achievement.title,
                    subtitle: achievement.description,
                    metric: "\(achievement.points) pts",
                    iconName: achievement.iconName,
                    brandName: "MyApp"
                )
            )
        }
    }
}

Share statistics:

ShareCardSheet(
    content: StatisticsCardContent(
        title: "Weekly Progress",
        stats: [
            StatItem(label: "Steps", value: "52,340"),
            StatItem(label: "Calories", value: "3,200"),
            StatItem(label: "Distance", value: "28.5 km"),
        ],
        brandName: "FitTracker"
    )
)

Share a quote:

ShareCardSheet(
    content: QuoteCardContent(
        quote: "The only way to do great work is to love what you do.",
        attribution: "Steve Jobs",
        brandName: "DailyQuotes"
    )
)

Inline ShareLink (without sheet):

struct QuickShareButton: View {
    let content: any ShareCardContent
    @State private var renderedImage: PlatformImage?

    var body: some View {
        Group {
            if let image = renderedImage {
                ShareLink(
                    item: Image(platformImage: image),
                    preview: SharePreview(content.title, image: Image(platformImage: image))
                )
            } else {
                ProgressView()
            }
        }
        .task {
            let renderer = ShareCardRenderer()
            renderedImage = await renderer.render(content: content, style: .branded)
        }
    }
}

Testing

@Test
func rendersAchievementCard() async throws {
    let content = AchievementCardContent(
        title: "First Run",
        subtitle: "Completed your first 5K run",
        metric: "500 pts",
        iconName: "figure.run",
        brandName: "FitApp"
    )

    let renderer = ShareCardRenderer()
    let image = await renderer.render(content: content, style: .branded)
    #expect(image != nil)
    #expect(image!.size.width > 0)
    #expect(image!.size.height > 0)
}

@Test
func allStylesRenderSuccessfully() async throws {
    let content = QuoteCardContent(
        quote: "Test quote",
        attribution: "Author",
        brandName: "App"
    )

    let renderer = ShareCardRenderer()
    for style in ShareCardStyle.allCases {
        let image = await renderer.render(content: content, style: style)
        #expect(image != nil, "Style \(style) failed to render")
    }
}

@Test
func qrCodeGeneratesValidImage() throws {
    let image = QRCodeGenerator.generate(
        from: "https://example.com/share/123",
        size: CGSize(width: 100, height: 100)
    )
    #expect(image != nil)
}

Common Patterns

Achievement Card

Best for: gamification, milestones, unlockables.

• Large icon or badge at top
• Achievement title prominently displayed
• Metric or point value highlighted
• App branding at bottom

Statistics Card

Best for: fitness, finance, productivity apps.

• Grid or list of stat items with labels and values
• Optional trend indicators (up/down arrows)
• Date range context
• App branding at bottom

Quote Card

Best for: reading, journaling, social apps.

• Large quotation marks or decorative element
• Quote text centered with elegant typography
• Attribution below quote
• Minimal branding

Gotchas

Image Quality for Different Platforms

• Instagram: JPEG works, but use high quality (0.9+) to avoid artifacts on text
• Twitter/X: PNG preserves text sharpness but larger file size
• Use @2x scale factor in ImageRenderer for Retina-quality output
• Always render at the display scale: renderer.scale = UIScreen.main.scale (iOS) or NSScreen.main?.backingScaleFactor (macOS)

Memory for Large Renders

• A 1080x1920 card at @3x scale = 3240x5760 pixels = ~75 MB in memory
• Render at @2x maximum for share cards — social platforms compress anyway
• Release the rendered image after sharing completes
• Use autoreleasepool if generating multiple cards in sequence

ImageRenderer Limitations

• ImageRenderer is @MainActor — must be called from the main thread
• Minimum iOS 16 / macOS 13
• Does not render Map, Camera, or WebView content
• Animations are not captured — renders a single frame
• ScrollView content beyond visible bounds is not rendered

Cross-Platform Rendering

• On macOS, ImageRenderer produces NSImage via nsImage property
• On iOS, use uiImage property
• Use the PlatformImage typealias pattern for shared code
• UIGraphicsImageRenderer is UIKit-only — prefer ImageRenderer for SwiftUI cross-platform code

ShareLink Gotchas

• ShareLink requires the shared item to conform to Transferable
• Image conforms to Transferable on iOS 16+ / macOS 13+
• For custom share items, implement Transferable with DataRepresentation
• ShareLink renders as a button — style it to match your UI

References

• templates.md — All production Swift templates
• Related: generators/image-loading — Cache rendered share card images
• Related: ios/deep-linking — Generate deep links for QR codes