A simple, powerful SwiftUI text editor for iOS and macOS with live syntax highlighting.

Highlight what's important as your users type.

Supports iOS 13.0+ and macOS 10.15+.

File -> Swift Packages -> Add Package Dependency and use the URL https://github.com/kyle-n/HighlightedTextEditor.

Add pod 'HighlightedTextEditor' to your Podfile and run pod install.

HighlightedTextEditor applies styles to text matching regex patterns you provide. You can apply multiple styles to each regex pattern, as shown in the example below.

import HighlightedTextEditor

// matches text between underscores
let betweenUnderscores = try! NSRegularExpression(pattern: "_[^_]+_", options: [])

struct ContentView: View {
    @State private var text: String = "here is _bold, italicized, red text_"
    
    private let rules: [HighlightRule] = [
        HighlightRule(pattern: betweenUnderscores, formattingRules: [
            TextFormattingRule(fontTraits: [.traitItalic, .traitBold]),
            TextFormattingRule(key: .foregroundColor, value: UIColor.red)
        ])
    ]
    
    var body: some View {
        VStack {
            HighlightedTextEditor(text: $text, highlightRules: rules)
                // optional modifiers
                .autocapitalizationType(.words)
                .keyboardType(.numberPad)
                .autocorrectionType(.no)
        }
    }
}

Notice the NSRegularExpression is instantiated once. It should not be recreated every time the view is redrawn. This helps performance.

I've included a few useful presets for syntax highlighting as static vars on [HighlightRule]. If you have ideas for other useful presets, please feel free to open a pull request with your preset code.

Current presets include:

• markdown
• url

Example of using a preset:

HighlightedTextEditor(text: $text, highlightRules: .markdown)

• .autocapitalizationType(_ type: UITextAutocapitalizationType)
• .autocorrectionType(_ type: UITextAutocorrectionType)
• .backgroundColor(_ color: UIColor)
• .defaultColor(_ color: UIColor)
• .defaultFont(_ font: UIFont)
• .keyboardType(_ type: UIKeyboardType)
• .insertionPointColor(_ color: UIColor)
• .multilineTextAlignment(_ alignment: TextAlignment)

• .allowsDocumentBackgroundColorChange(_ allowsChange: Bool)
• .backgroundColor(_ color: NSColor)
• .defaultColor(_ color: NSColor)
• .defaultFont(_ font: NSFont)
• .drawsBackground(_ shouldDraw: Bool)
• .insertionPointColor(_ color: NSColor)
• .multilineTextAlignment(_ alignment: TextAlignment)

TextFormattingRule uses two different initializers that each set one style.

value uses an older, untyped API so you'll have to check the documentation for what type can be passed in for a given key.

If you are targeting iOS 14 / macOS 11, you can use a convenience initializer taking advantage of new SwiftUI APIs for converting Colors to UIColors or NSColors.

Apple, in its wisdom, has not enabled these features for the XCode 12 GM. If you are using the XCode beta and want to enable this initializer, go to project_name -> Targets -> specified platform -> Build Settings -> Swift Compiler - Custom Flags and add flag -DBETA. <

Are you using HighlightedTextEditor in your app? I would love to feature you here! Please open a pull request that adds a new bullet to the list below with your app's name and a link to its TestFlight or App Store page.

• MongoKitten

AppKit text editor code based on MacEditorTextView by Thiago Holanda.

Created by Kyle Nazario.