feat(ios): add link rendering, theme, and onLinkPress

packages/ios-enriched-markdown/Sources/EnrichedMarkdown/Rendering/RendererFactory.swift

@@ -41,6 +41,8 @@ final class RendererFactory {
             return EmphasisRenderer(factory: self, config: config)
         case .heading:
             return HeadingRenderer(factory: self, config: config)
+        case .link:
+            return LinkRenderer(factory: self, config: config)
         default:
             return childrenOnlyRenderer
         }

packages/ios-enriched-markdown/Sources/EnrichedMarkdown/Rendering/Renderers/LinkRenderer.swift

@@ -0,0 +1,36 @@
+import UIKit
+
+final class LinkRenderer: NodeRenderer {
+    private let factory: RendererFactory
+    private let config: MarkdownStyleConfig
+
+    init(factory: RendererFactory, config: MarkdownStyleConfig) {
+        self.factory = factory
+        self.config = config
+    }
+
+    func render(node: MarkdownASTNode, into output: NSMutableAttributedString, context: RenderContext) {
+        let start = output.length
+        factory.renderChildren(of: node, into: output, context: context)
+
+        let range = RenderContext.rangeForRenderedContent(in: output, start: start)
+        guard range.length > 0 else { return }
+
+        let url = node.attribute("url") ?? ""
+        let linkStyle = config.link
+        let linkColor = linkStyle.foregroundColor
+        let underline = linkStyle.underline ?? true
+        let underlineStyle = underline ? NSUnderlineStyle.single.rawValue : 0
+
+        let linkValue: Any = URL(string: url) ?? url
+        output.addAttribute(.link, value: linkValue, range: range)
+
+        output.enumerateAttributes(in: range, options: []) { _, subrange, _ in
+            if let linkColor {
+                output.addAttribute(.foregroundColor, value: linkColor, range: subrange)
+                output.addAttribute(.underlineColor, value: linkColor, range: subrange)
+            }
+            output.addAttribute(.underlineStyle, value: underlineStyle, range: subrange)
+        }
+    }
+}

packages/ios-enriched-markdown/Sources/EnrichedMarkdown/Theme/DefaultMarkdownTheme.swift

@@ -45,6 +45,10 @@ enum DefaultMarkdownTheme {
                 .foregroundStyle(Semantic.secondary)
                 .marginBottom(8)
 
+            Link()
+                .foregroundStyle(Semantic.tint)
+                .underline()
+
             Strong()
             Emphasis()
         }

packages/ios-enriched-markdown/Sources/EnrichedMarkdown/Theme/Elements/Link.swift

@@ -0,0 +1,28 @@
+import SwiftUI
+
+public struct Link: MarkdownThemeElement {
+    public var fontSpec: ThemeFontSpec?
+    public var fontWeight: Font.Weight?
+    public var fontDesign: Font.Design?
+    public var foregroundColorSpec: ThemeColorSpec?
+    public var marginTop: CGFloat?
+    public var marginBottom: CGFloat?
+    public var lineHeight: CGFloat?
+    public var textAlignment: TextAlignment?
+    public var underline: Bool?
+
+    public init() {}
+
+    public func underline(_ enabled: Bool = true) -> Self {
+        var copy = self
+        copy.underline = enabled
+        return copy
+    }
+
+    public func apply(to config: inout MarkdownStyleConfig, traitCollection: UITraitCollection) {
+        applyElementStyle(to: &config.link, traitCollection: traitCollection)
+        if let underline {
+            config.link.underline = underline
+        }
+    }
+}

packages/ios-enriched-markdown/Sources/EnrichedMarkdown/Theme/MarkdownStyleConfig.swift

@@ -7,21 +7,24 @@ public struct ElementStyle: Equatable, Sendable {
     public var marginBottom: CGFloat?
     public var lineHeight: CGFloat?
     public var textAlignment: NSTextAlignment?
+    public var underline: Bool?
 
     public init(
         font: UIFont? = nil,
         foregroundColor: UIColor? = nil,
         marginTop: CGFloat? = nil,
         marginBottom: CGFloat? = nil,
         lineHeight: CGFloat? = nil,
-        textAlignment: NSTextAlignment? = nil
+        textAlignment: NSTextAlignment? = nil,
+        underline: Bool? = nil
     ) {
         self.font = font
         self.foregroundColor = foregroundColor
         self.marginTop = marginTop
         self.marginBottom = marginBottom
         self.lineHeight = lineHeight
         self.textAlignment = textAlignment
+        self.underline = underline
     }
 
     public mutating func merge(_ other: ElementStyle) {
@@ -31,6 +34,7 @@ public struct ElementStyle: Equatable, Sendable {
         if let marginBottom = other.marginBottom { self.marginBottom = marginBottom }
         if let lineHeight = other.lineHeight { self.lineHeight = lineHeight }
         if let textAlignment = other.textAlignment { self.textAlignment = textAlignment }
+        if let underline = other.underline { self.underline = underline }
     }
 }
 
@@ -42,6 +46,7 @@ public struct MarkdownStyleConfig: Equatable, Sendable {
     public var heading4: ElementStyle
     public var heading5: ElementStyle
     public var heading6: ElementStyle
+    public var link: ElementStyle
     public var strong: ElementStyle
     public var emphasis: ElementStyle
 
@@ -53,6 +58,7 @@ public struct MarkdownStyleConfig: Equatable, Sendable {
         heading4: ElementStyle = ElementStyle(),
         heading5: ElementStyle = ElementStyle(),
         heading6: ElementStyle = ElementStyle(),
+        link: ElementStyle = ElementStyle(),
         strong: ElementStyle = ElementStyle(),
         emphasis: ElementStyle = ElementStyle()
     ) {
@@ -63,6 +69,7 @@ public struct MarkdownStyleConfig: Equatable, Sendable {
         self.heading4 = heading4
         self.heading5 = heading5
         self.heading6 = heading6
+        self.link = link
         self.strong = strong
         self.emphasis = emphasis
     }
@@ -75,6 +82,7 @@ public struct MarkdownStyleConfig: Equatable, Sendable {
         heading4.merge(other.heading4)
         heading5.merge(other.heading5)
         heading6.merge(other.heading6)
+        link.merge(other.link)
         strong.merge(other.strong)
         emphasis.merge(other.emphasis)
     }
@@ -102,4 +110,3 @@ public struct MarkdownStyleConfig: Equatable, Sendable {
         default: heading1 = style
         }
     }
-}

packages/ios-enriched-markdown/Sources/EnrichedMarkdown/Views/Environment+LinkPress.swift

@@ -0,0 +1,18 @@
+import SwiftUI
+
+private struct MarkdownLinkPressHandlerKey: EnvironmentKey {
+    static let defaultValue: ((URL) -> Void)? = nil
+}
+
+public extension EnvironmentValues {
+    var markdownLinkPressHandler: ((URL) -> Void)? {
+        get { self[MarkdownLinkPressHandlerKey.self] }
+        set { self[MarkdownLinkPressHandlerKey.self] = newValue }
+    }
+}
+
+public extension View {
+    func onLinkPress(_ action: @escaping (URL) -> Void) -> some View {
+        environment(\.markdownLinkPressHandler, action)
+    }
+}

packages/ios-enriched-markdown/Sources/EnrichedMarkdown/Views/MarkdownTextViewRepresentable.swift

@@ -3,21 +3,50 @@ import UIKit
 
 struct MarkdownTextViewRepresentable: UIViewRepresentable {
     let attributedText: NSAttributedString
+    let onLinkPress: ((URL) -> Void)?
+
+    func makeCoordinator() -> Coordinator {
+        Coordinator()
+    }
 
     func makeUIView(context: Context) -> MarkdownTextView {
-        MarkdownTextView()
+        let textView = MarkdownTextView()
+        textView.delegate = context.coordinator
+        return textView
     }
 
     func updateUIView(_ textView: MarkdownTextView, context: Context) {
+        context.coordinator.onLinkPress = onLinkPress
         textView.setMarkdownAttributedText(attributedText)
     }
 
+    static func dismantleUIView(_ uiView: MarkdownTextView, coordinator: Coordinator) {
+        uiView.delegate = nil
+    }
+
     @available(iOS 16.0, *)
     func sizeThatFits(_ proposal: ProposedViewSize, uiView: MarkdownTextView, context: Context) -> CGSize? {
         let width = proposal.width ?? UIScreen.main.bounds.width
         let size = uiView.sizeThatFits(CGSize(width: width, height: .greatestFiniteMagnitude))
         return CGSize(width: width, height: size.height)
     }
+
+    final class Coordinator: NSObject, UITextViewDelegate {
+        var onLinkPress: ((URL) -> Void)?
+
+        func textView(
+            _ textView: UITextView,
+            shouldInteractWith URL: URL,
+            in characterRange: NSRange,
+            interaction: UITextItemInteraction
+        ) -> Bool {
+            if let onLinkPress {
+                onLinkPress(URL)
+                return false
+            }
+            return true
+        }
+    }
 }
 
 final class MarkdownTextView: UITextView {
@@ -42,10 +71,13 @@ final class MarkdownTextView: UITextView {
 
     private func configure() {
         isEditable = false
+        isSelectable = true
         isScrollEnabled = false
         backgroundColor = .clear
         textContainerInset = .zero
         textContainer.lineFragmentPadding = 0
+        dataDetectorTypes = []
+        linkTextAttributes = [:]
         setContentCompressionResistancePriority(.defaultLow, for: .horizontal)
     }
 

packages/ios-enriched-markdown/Tests/EnrichedMarkdownTests/RendererTests.swift

@@ -209,6 +209,97 @@ final class RendererTests: XCTestCase {
         }
         XCTAssertTrue(boldFound)
     }
+
+
+    func testLinkHasURLAttribute() {
+        let result = MarkdownRenderer.render("[text](https://example.com)", config: config)
+        XCTAssertTrue(result.string.contains("text"))
+
+        var foundLink = false
+        result.enumerateAttribute(.link, in: NSRange(location: 0, length: result.length)) { value, range, _ in
+            let urlString: String?
+            if let url = value as? URL {
+                urlString = url.absoluteString
+            } else {
+                urlString = value as? String
+            }
+            guard let urlString else { return }
+            let substring = (result.string as NSString).substring(with: range)
+            if substring == "text" {
+                XCTAssertEqual(urlString, "https://example.com")
+                foundLink = true
+            }
+        }
+        XCTAssertTrue(foundLink)
+    }
+
+
+    func testLinkThemeOverrideAppliesColor() {
+        var customConfig = config!
+        customConfig.link.foregroundColor = .systemBlue
+
+        let result = MarkdownRenderer.render("[link](https://example.com)", config: customConfig)
+
+        var foundBlue = false
+        result.enumerateAttribute(.foregroundColor, in: NSRange(location: 0, length: result.length)) { value, range, _ in
+            guard let color = value as? UIColor else { return }
+            if result.string[range] == "link" {
+                XCTAssertEqual(color, UIColor.systemBlue)
+                foundBlue = true
+            }
+        }
+        XCTAssertTrue(foundBlue)
+    }
+
+
+    func testLinkInsideParagraphWithInlineStyles() {
+        let result = MarkdownRenderer.render("**bold** and [link](https://example.com) and *italic*", config: config)
+        XCTAssertTrue(result.string.contains("link"))
+
+        var linkFound = false
+        result.enumerateAttribute(.link, in: NSRange(location: 0, length: result.length)) { value, range, _ in
+            guard value != nil else { return }
+            if result.string[range] == "link" {
+                linkFound = true
+            }
+        }
+        XCTAssertTrue(linkFound)
+    }
+
+
+    func testAllAttributeRangesWithinBounds() {
+        let samples = [
+            "# Heading one\n\n## Heading two\n\nA paragraph with a [link](https://example.com) and **bold** nearby.",
+            Self.headingsAndLinksFixture,
+            "Plain\n\n**bold**",
+            "Line one  \nLine two",
+            "Use `code` and **bold**",
+            "![Mountain](https://example.com/img.png)",
+            "Hello ![icon](https://example.com/icon.png) world",
+            "---",
+            "```\ncode\n```",
+            "> quote",
+            "- item",
+            "1. ordered"
+        ]
+
+        for sample in samples {
+            let result = MarkdownRenderer.render(sample, config: config)
+            let length = result.length
+            result.enumerateAttributes(in: NSRange(location: 0, length: length)) { _, range, _ in
+                XCTAssertGreaterThanOrEqual(range.location, 0)
+                XCTAssertLessThanOrEqual(NSMaxRange(range), length)
+            }
+        }
+    }
+
+    private static let headingsAndLinksFixture = """
+    # Heading one
+
+    ## Heading two
+
+    A paragraph with a [link](https://example.com) and **bold** nearby.
+    """
 }
 
 private extension String {