MarkdownTextView

Rich Markdown Editing for iOS

MarkdownTextView is an iOS framework for adding rich Markdown editing capabilities. Support for Markdown syntax is implemented inside an easily extensible NSTextStorage subclass, with a UITextView subclass being provided for convenience.

Screenshot

Example App

Check out the includeded Example app to try out the text view and to see how MarkdownTextView is integrated into the project.

Installation

With CocoaPods:

pod "MarkdownTextView"

With Carthage:

github "indragiek/MarkdownTextView"

Getting Started

The simplest possible usage is as follows:

let textView = MarkdownTextView(frame: CGRectZero)
view.addSubview(textView)

This gives you a text view with support for most of the features defined in the original Markdown implementation (strong, emphasis, inline code, code blocks, block quotes, headers) with the default styling provided by the framework.

Customizing Appearance

All of the styling can be customized using standard NSAttributedString attributes. For example, if you wanted to customize bold text such that it appeared red, you would do this:

var attributes = MarkdownTextAttributes()
attributes.strongAttributes = [
	NSForegroundColorAttributeName: UIColor.redColor()
]
let textStorage = MarkdownTextStorage(attributes: attributes)
let textView = MarkdownTextView(frame: CGRectZero, textStorage: textStorage)
view.addSubview(textView)

Extensions Support

Extension classes conforming to the HighlighterType protocol can be used to add support for unofficial Markdown extensions. The framework comes with the following extensions already implemented:

From Github Flavored Markdown:

• MarkdownStrikethroughHighlighter - Support for ~~strikethrough~~
• MarkdownFencedCodeHighlighter - Support for fenced code blocks
• LinkHighlighter - Support for auto-linking

Other:

• MarkdownSuperscriptHighlighter - Support for super^scripted^text

These extensions do not come activated by default. They must manually be added to an instance of MarkdownTextStorage as follows:

let textStorage = MarkdownTextStorage()
var error: NSError?
if let linkHighlighter = LinkHighlighter(errorPtr: &error) {
    textStorage.addHighlighter(linkHighlighter)
} else {
    assertionFailure("Error initializing LinkHighlighter: \(error)")
}
textStorage.addHighlighter(MarkdownStrikethroughHighlighter())
textStorage.addHighlighter(MarkdownSuperscriptHighlighter())
if let codeBlockAttributes = attributes.codeBlockAttributes {
    textStorage.addHighlighter(MarkdownFencedCodeHighlighter(attributes: codeBlockAttributes))
}

let textView = MarkdownTextView(frame: CGRectZero, textStorage: textStorage)
view.addSubview(textView)

Credits

• John Gruber's original Markdown implementation for most of the regular expressions used in this project.
• RFMarkdownTextView for the idea to implement this as an NSTextStorage subclass

Contact

• Indragie Karunaratne
• @indragie
• http://indragie.com

License

MarkdownTextView is licensed under the MIT License. See LICENSE for more information.