https://github.com/appstefan/HighlightSwift
Code syntax highlighting in Swift and SwiftUI
https://github.com/appstefan/HighlightSwift
ios macos swift swiftui syntax-highlighting tvos
Last synced: 2 days ago
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Code syntax highlighting in Swift and SwiftUI
- Host: GitHub
- URL: https://github.com/appstefan/HighlightSwift
- Owner: appstefan
- License: mit
- Created: 2023-05-11T15:17:41.000Z (about 3 years ago)
- Default Branch: main
- Last Pushed: 2024-11-27T17:42:48.000Z (over 1 year ago)
- Last Synced: 2026-05-29T00:28:06.356Z (about 1 month ago)
- Topics: ios, macos, swift, swiftui, syntax-highlighting, tvos
- Language: Swift
- Homepage:
- Size: 758 KB
- Stars: 202
- Watchers: 6
- Forks: 37
- Open Issues: 9
-
Metadata Files:
- Readme: README.md
- License: LICENSE.md
Awesome Lists containing this project
- awesome-swift - HighlightSwift - Convert code strings into syntax highlighted `AttributedString` in Swift and SwiftUI. (Utilities and Extensions)
README
# HighlightSwift
[](https://swiftpackageindex.com/appstefan/HighlightSwift)
[](https://swiftpackageindex.com/appstefan/HighlightSwift)
Syntax Highlighting for Swift and SwiftUI
## Contents
#### `Highlight`
Swift class to convert a `String` of code into a syntax highlighted `AttributedString`
* 🔍 Automatic language detection
* 📚 Support for 50+ common languages
* 🌈 Choose from 30 built-in color themes or use custom CSS
* 🧰 Built with [highlight.js](https://github.com/highlightjs/highlight.js) & `JavaScriptCore`
* ☑️ Complete concurrency checking enabled
* 🖥️ Works on iOS, iPadOS, macOS, and tvOS
#### `CodeText`
SwiftUI view to display a `String` of code with syntax highlighting
* 🌗 Color theme syncs automatically with Dark Mode
* 📜 Theme background color included with `.card` style
* 🔠 Works with `Text` modifiers like `.bold()` or `.font()`
* ⚙️ Includes modifiers to set the color theme, style & language
* 📫 Callback modifiers to get the highlight results, language & score
* 🍃 Memory efficient using an internal `Highlight` environment entry
## Highlight
Create an instance of `Highlight` and convert a `String` of code into a syntax highlighted `AttributedString`:
```swift
let someCode = """
print(\"Hello World\")
"""
let highlight = Highlight()
let attributedText = try await highlight.attributedText(someCode)
```
Add the `language:` parameter to set the language and disable automatic language detection:
```swift
let attributedText = try await highlight.attributedText(someCode, language: "swift")
```
Use the `colors:` parameter to change the color theme.
```swift
let attributedText = try await highlight.attributedText(someCode, colors: .dark(.github))
```
Apply a custom CSS theme with the `.custom` option.
Refer to the highlight.js [Theme Guide](https://highlightjs.readthedocs.io/en/latest/theme-guide.html#) for details:
```swift
let someCSS = """
.hljs {
display: block;
overflow-x: auto;
padding: 0.5em;
}
"""
let attributedText = try await highlight.attributedText(someCode, colors: .custom(css: someCSS))
```
The `.request()` function returns a `HighlightResult` with extra information:
```swift
let result: HighlightResult = try await highlight.request(someCode)
print(result)
```
```swift
HighlightResult(
attributedText: "...",
relevance: 5,
language: "swift",
languageName: "Swift?",
backgroundColor: #1F2024FF,
hasIllegal: false,
isUndefined: false)
```
##
### `CodeText`
Create a `CodeText` view with some code:
```swift
let someCode: String = """
print(\"Hello World\")
"""
var body: some View {
CodeText(someCode)
}
```
The font design is always `.monospaced`.
Other text modifiers can be applied:
```swift
CodeText(someCode)
.font(.callout)
.fontWeight(.semibold)
```
Add the `.highlightLanguage()` modifier to set the language and disable automatic detection:
```swift
CodeText(someCode)
.highlightLanguage(.swift)
```
#### Colors
Add the `.codeTextColors()` modifier to set the color theme. The built-in color themes update automatically with Dark Mode to the corresponding dark variant.
```swift
CodeText(someCode)
.codeTextColors(.github)
```
Choose the `.custom` option to use any custom CSS color theme. Refer to the official highlight.js [Theme Guide](https://highlightjs.readthedocs.io/en/latest/theme-guide.html#) for more info.
```swift
CodeText(someCode)
.codeTextColors(.custom(dark: .custom(css: someDarkCSS), light: .custom(css: someLightCSS)))
```
#### Styles
The default style is `.plain` without any background or padding. Some of the color themes are more legible with their corresponding background color. Add the `.codeTextStyle()` modifier and choose the `.card` style to show the background:
```swift
CodeText(someCode)
.codeTextStyle(.card)
```
The `.card` style has a few customization options, for example:
```swift
CodeText(someCode)
.codeTextStyle(.card(cornerRadius: 0, stroke: .separator, verticalPadding: 12))
```
#### Results
Add `.onHighlightSuccess()` to get the highlight results, including the detected language, relevancy score, background color and other details. Unexpected errors are unlikely but can be handled with `.onHighlightFailure()` if necessary for debugging.
```swift
CodeText(someCode)
.onHighlightSuccess { result in
...
}
.onHighlightFailure { error in
...
}
```
There is also a combined `.onHighlightResult()` equivalent of the two callbacks above.
```swift
CodeText(someCode)
.onHighlightResult { result in
switch result {
case .success:
...
case .failure:
...
}
}
```
A previously stored highlight result can be passed to the `CodeText`.
In combination with `.onHighlightSuccess()` the result can be persisted when the view might reappear frequently, such as in a list view:
```swift
let someCode: String = """
print(\"Hello World\")
"""
@State var result: HighlightResult?
var body: some View {
List {
...
CodeText(someCode, result: result)
.onHighlightSuccess { result in
self.result = result
}
...
}
}
```
## Installation
### Project
1. In Xcode, go to `File` > `Add packages...`
2. Enter `https://github.com/appstefan/highlightswift` in the field and click `Add Package`
### Package
In `Package.swift` add this repository as a dependency:
```swift
dependencies: [
.package(url: "https://github.com/appstefan/highlightswift.git", from: "1.1")
],
targets: [
.target(
name: "YourPackageName",
dependencies: ["HighlightSwift"]
)
]
```
## Author
Stefan, thrower_ranges.0d@icloud.com
## License
HighlightSwift is available under the MIT license. See the [LICENSE.md](/LICENSE.md) file.
Highlight.js is available under the BSD license. See the [LICENSE.md](/Sources/HighlightSwift/HighlightJS/LICENSE.md) file.