swiftui-text-editing

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Styled Text Editing

Patterns for displaying styled text and building rich text editors in SwiftUI. Covers Text styling, AttributedString, TextEditor with selection-based formatting, and custom formatting definitions.

When This Skill Activates

Use this skill when the user:

• Wants to display styled or formatted text
• Needs rich text editing with bold/italic/underline controls
• Asks about AttributedString or TextEditor
• Wants text formatting toolbars
• Asks about Markdown rendering in Text views
• Needs custom text attributes or formatting constraints
• Wants selection-based text formatting

Decision Tree

What text feature do you need?
|
+- Display styled read-only text
|  +- Simple styling (one style) -> Text Styling section below
|  +- Mixed styles in one string -> AttributedString section below
|  +- Markdown content -> Markdown section below
|
+- Edit plain text
|  +- TextEditor(text: $stringBinding)
|
+- Edit rich/styled text
|  +- Basic rich editor -> Rich Text Editing section below
|  +- With formatting toolbar -> Formatting Controls section below
|  +- With custom constraints -> Custom Formatting section below

API Availability

API	Minimum Version	Notes
Text with modifiers	iOS 13	.font(), .bold(), .italic()
TextEditor(text:)	iOS 14	Plain string binding
.foregroundStyle()	iOS 15	Preferred over .foregroundColor()
AttributedString	iOS 15	Rich text model
.bold(condition)	iOS 16	Conditional bold/italic
.underline(pattern:)	iOS 16	Dash, dot patterns
TextEditor(text:selection:)	iOS 18	AttributedString + selection
AttributedTextSelection	iOS 18	Selection-based formatting
text.transformAttributes(in:)	iOS 18	Modify attributes in selection
AttributedTextFormattingDefinition	iOS 18	Custom formatting constraints
@Environment(\.fontResolutionContext)	iOS 18	Resolve font properties

Top 5 Mistakes

#	Mistake	Fix
1	Using .foregroundColor() on new projects	Use .foregroundStyle() — supports gradients and ShapeStyle
2	.animation(.spring()) without value: on text	Deprecated in iOS 15 — always pass value: parameter
3	Expecting full Markdown in Text	Text only supports inline Markdown: bold, italic, [links]. No lists, tables, code blocks, images
4	Creating new AttributedString instances on every body evaluation	Cache complex AttributedString objects in @State or computed properties outside body
5	Using TextEditor(text: $string) for rich text	Use TextEditor(text: $attributedString, selection: $selection) with AttributedString binding (iOS 18+)

Text Styling Quick Reference

// Font
Text("Hello").font(.headline)
Text("Custom").font(.system(size: 24, design: .rounded))

// Weight
Text("Bold").fontWeight(.bold)

// Color — prefer foregroundStyle over foregroundColor
Text("Styled").foregroundStyle(.red)
Text("Gradient").foregroundStyle(
    .linearGradient(colors: [.yellow, .blue], startPoint: .top, endPoint: .bottom)
)

// Decorations
Text("Bold").bold()
Text("Conditional").bold(someCondition)
Text("Underline").underline(true, pattern: .dash, color: .blue)
Text("Strike").strikethrough(true, pattern: .dot, color: .red)

// Layout
Text("Centered").multilineTextAlignment(.center)
Text("Spaced").lineSpacing(10)
Text("Truncated").lineLimit(2).truncationMode(.tail)

AttributedString

// Create and style ranges
var text = AttributedString("Red and Blue")
if let redRange = text.range(of: "Red") {
    text[redRange].foregroundColor = .red
    text[redRange].font = .headline
}
if let blueRange = text.range(of: "Blue") {
    text[blueRange].foregroundColor = .blue
    text[blueRange].underlineStyle = .single
}

// Display
Text(text)

Available Attributes

Attribute	Type	Example
.font	Font	.headline
.foregroundColor	Color	.red
.backgroundColor	Color	.yellow
.underlineStyle	UnderlineStyle	.single
.underlineColor	Color	.blue
.strikethroughStyle	UnderlineStyle	.single
.strikethroughColor	Color	.red
.inlinePresentationIntent	InlinePresentationIntent	.stronglyEmphasized (bold), .emphasized (italic)

Rich Text Editing (iOS 18+)

struct RichTextEditorView: View {
    @State private var text = AttributedString("Select text to format")
    @State private var selection = AttributedTextSelection()

    @Environment(\.fontResolutionContext) private var fontResolutionContext

    var body: some View {
        VStack {
            TextEditor(text: $text, selection: $selection)
                .frame(height: 200)

            HStack {
                Button(action: toggleBold) {
                    Image(systemName: "bold")
                }
                Button(action: toggleItalic) {
                    Image(systemName: "italic")
                }
                Button(action: toggleUnderline) {
                    Image(systemName: "underline")
                }
            }
        }
    }

    private func toggleBold() {
        text.transformAttributes(in: &selection) {
            let font = $0.font ?? .default
            let resolved = font.resolve(in: fontResolutionContext)
            $0.font = font.bold(!resolved.isBold)
        }
    }

    private func toggleItalic() {
        text.transformAttributes(in: &selection) {
            let font = $0.font ?? .default
            let resolved = font.resolve(in: fontResolutionContext)
            $0.font = font.italic(!resolved.isItalic)
        }
    }

    private func toggleUnderline() {
        text.transformAttributes(in: &selection) {
            if $0.underlineStyle != nil {
                $0.underlineStyle = nil
            } else {
                $0.underlineStyle = .single
            }
        }
    }
}

Reading Selection Attributes

// Get current attributes at the selection/cursor
let attributes = selection.typingAttributes(in: text)
let currentColor = attributes.foregroundColor ?? .primary

// Set color on selection
text.transformAttributes(in: &selection) {
    $0.foregroundColor = .blue
}

Custom Formatting Definition (iOS 18+)

Constrain which formatting options are available in the editor:

struct MyTextFormatting: AttributedTextFormattingDefinition {
    typealias Scope = AttributeScopes.SwiftUIAttributes

    static let fontWeight = ValueConstraint(
        \.font,
        constraint: { font in
            guard let font = font else { return nil }
            let weight = font.resolve().weight
            return font.weight(weight == .bold ? .regular : .bold)
        }
    )
}

// Apply to TextEditor
TextEditor(text: $text, selection: $selection)
    .textFormattingDefinition(MyTextFormatting.self)

Markdown in Text

// Inline markdown support
Text("This is **bold** and *italic* text")
Text("Visit [Apple](https://www.apple.com)")
Text("Code: `inline code`")

Markdown Limitations

Text supports only inline Markdown:

• ✅ Bold (**text**), italic (*text*), links, inline code
• ❌ Line breaks, block formatting, lists, tables, code blocks, images, block quotes

Review Checklist

Text Display

• Using .foregroundStyle() instead of deprecated .foregroundColor()
• .lineLimit() paired with .help() tooltip or .textSelection(.enabled) for truncated text
• Dynamic Type supported — using system font styles, not hardcoded sizes
• Colors adapt to dark mode — using system colors or semantic styles

AttributedString

• Complex AttributedString cached in @State, not recreated in body
• Range lookups use safe if let range = text.range(of:) pattern
• Appropriate attributes used (.inlinePresentationIntent for semantic bold/italic)

TextEditor

• Rich text uses TextEditor(text: $attributedString, selection: $selection) (iOS 18+)
• Formatting toolbar uses text.transformAttributes(in: &selection) pattern
• Font resolution uses @Environment(\.fontResolutionContext) for toggle logic
• Accessibility labels provided for formatting buttons

Localization

• User-facing strings use LocalizedStringKey
• Markdown in localized strings uses Text(LocalizedStringKey("**Bold** text"))

References

• SwiftUI Text and Symbol Modifiers
• Building Rich SwiftUI Text Experiences
• AttributedString Documentation
• TextEditor Documentation