♻️ Update experience font parsing

Sources/AppcuesKit/Data/Models/Experience/ExperienceComponent.swift

@@ -184,7 +184,7 @@ extension ExperienceComponent {
 
         let fontName: String?
         let fontSize: Double?
-        let fontWeight: String?
+        let fontWeight: Double?
         let letterSpacing: Double?
         let lineHeight: Double?
         let textAlignment: String?
@@ -211,7 +211,7 @@ extension ExperienceComponent {
             width: Double? = nil,
             fontName: String? = nil,
             fontSize: Double? = nil,
-            fontWeight: String? = nil,
+            fontWeight: Double? = nil,
             letterSpacing: Double? = nil,
             lineHeight: Double? = nil,
             textAlignment: String? = nil,

Sources/AppcuesKit/Presentation/Extensions/Inits/Font+Double.swift

@@ -0,0 +1,108 @@
+//
+//  Font+Double.swift
+//  Appcues
+//
+//  Created by Matt on 2021-11-02.
+//
+
+import SwiftUI
+
+@available(iOS 13.0, *)
+extension Font {
+
+    /// Init `Font` from an experience JSON model values.
+    init?(name: String?, size: Double?, weight: Double?) {
+        guard let size = CGFloat(size) else { return nil }
+        guard let name = name else {
+            self = .system(size: size, weight: Font.Weight(double: weight) ?? .regular)
+            return
+        }
+
+        // A space is invalid for PostScript font names, and so we can safely avoid collisions with a custom font named "System".
+        if name.starts(with: "System ") {
+            // Expected format is `System $Design $Weight`.
+            let parts = name.split(separator: " ")
+            if parts.count == 3 {
+                self = .system(
+                    size: size,
+                    weight: Font.Weight(string: String(parts[2])) ?? .regular,
+                    design: Font.Design(string: String(parts[1])) ?? .default
+                )
+            } else {
+                self = .system(size: size)
+            }
+        } else {
+            if let weight = weight {
+                self = .custom(name, size: size, weight: weight)
+            } else {
+                self = .custom(name, size: size)
+            }
+        }
+    }
+
+    static func custom(_ name: String, size: CGFloat = UIFont.labelFontSize, weight: CGFloat = 0) -> Font {
+        let descriptor = UIFontDescriptor(fontAttributes: [
+            .name: name,
+            kCTFontVariationAttribute as UIFontDescriptor.AttributeName: [
+                // 0x77676874 == OpenType variation axis tag for `wght`
+                // https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6fvar.html
+                0x77676874: weight
+            ]
+        ])
+
+        return Font(UIFont(descriptor: descriptor, size: size))
+    }
+}
+
+@available(iOS 13.0, *)
+extension Font.Weight {
+
+    /// Init `Font.Weight` from an experience JSON fontName keyword.
+    init?(string: String?) {
+        switch string {
+        case "Black": self = .black
+        case "Heavy": self = .heavy
+        case "Bold": self = .bold
+        case "Semibold": self = .semibold
+        case "Medium": self = .medium
+        case "Regular": self = .regular
+        case "Light": self = .light
+        case "Thin": self = .thin
+        case "Ultralight": self = .ultraLight
+        default: return nil
+        }
+    }
+
+    /// Init `Font.Weight` from an experience JSON model value.
+    init?(double: Double?) {
+        guard let double = double else { return nil }
+
+        switch double {
+        case 850...1_000: self = .black
+        case 750..<850: self = .heavy
+        case 650..<750: self = .bold
+        case 550..<650: self = .semibold
+        case 450..<550: self = .medium
+        case 350..<450: self = .regular
+        case 250..<350: self = .light
+        case 150..<250: self = .thin
+        case 1..<150: self = .ultraLight
+        default: return nil
+        }
+    }
+}
+
+@available(iOS 13.0, *)
+extension Font.Design {
+
+    /// Init `Font.Design` from an experience JSON fontName keyword.
+    init?(string: String?) {
+        switch string {
+        case "Default": self = .default
+        case "Monospaced": self = .monospaced
+        case "Rounded": self = .rounded
+        case "Serif": self = .serif
+        default: return nil
+        }
+    }
+}

Sources/AppcuesKit/Presentation/UI/AppcuesStyle.swift

@@ -56,7 +56,7 @@ internal struct AppcuesStyle {
         self.horizontalAlignment = HorizontalAlignment(string: model?.horizontalAlignment) ?? .center
         self.verticalAlignment = VerticalAlignment(string: model?.verticalAlignment) ?? .center
 
-        let fontSize = model?.fontSize ?? 17
+        let fontSize = model?.fontSize ?? UIFont.labelFontSize
         self.font = Font(name: model?.fontName, size: fontSize, weight: model?.fontWeight)
         self.letterSpacing = CGFloat(model?.letterSpacing)
         if let lineHeight = CGFloat(model?.lineHeight) {