Interactive label

FullInteractiveLabel.swift

import UIKit
import PlaygroundSupport

final class FullInteractiveLabel: UILabel {

    private let dataDetector: NSDataDetector?
    private var detectedResults: [NSTextCheckingResult] {
        guard let text = attributedText?.string ?? self.text else { return [] }

        return dataDetector?.matches(in: text, range: NSRange(location: 0, length: text.count)) ?? []
    }
    private let tapGesture = UITapGestureRecognizer()
    private let layoutManager = NSLayoutManager()
    private let textContainer = NSTextContainer(size: .zero)
    private let textStorage = NSTextStorage()
    override var text: String? {
        didSet {
            guard !detectedResults.isEmpty else { return }
            guard let text = self.text else { return }

            attributedText = NSAttributedString(string: text,
                                                            attributes: [.foregroundColor: textColor, .font: font])
        }
    }

    override var attributedText: NSAttributedString? {
        didSet {
            let results = detectedResults
            
            guard !results.isEmpty else { return }
            guard let oldText = attributedText, !oldText.string.isEmpty else {
                textStorage.setAttributedString(NSAttributedString())
                return
            }

            let mutableText = NSMutableAttributedString(attributedString: oldText)

            results.forEach {
                mutableText.addAttribute(.foregroundColor, value: resultsColor, range: $0.range)
            }

            guard oldText != mutableText else {
                textStorage.setAttributedString(mutableText)
                return
            }

            attributedText = mutableText
        }
    }
    override var lineBreakMode: NSLineBreakMode {
        didSet {
            textContainer.lineBreakMode = lineBreakMode
        }
    }
    override var numberOfLines: Int {
        didSet {
            textContainer.maximumNumberOfLines = numberOfLines
        }
    }
    private let resultsColor: UIColor
    private var detectedResultTapped: (NSTextCheckingResult, String) -> Void = { _, _ in }


    // MARK: - Callbacks

    func onDetectedDataTap(execute work: @escaping (NSTextCheckingResult, String) -> Void) {
        detectedResultTapped = work
    }

    private func didTapDetectedResult(_ result: NSTextCheckingResult, on text: String) {
        detectedResultTapped(result, text)
    }


    // MARK: - Update

    override func layoutSubviews() {
        super.layoutSubviews()
        textContainer.size = bounds.size
    }

    @objc
    private func tapped(_ gesture: UITapGestureRecognizer) {
        gesture.cancelsTouchesInView = false
        
        let results = detectedResults
        
        guard !results.isEmpty else { return }
        guard gesture.state == .ended else { return }
        guard let text = self.text else { return }

        let touchLocation = gesture.location(in: gesture.view)
        let indexOfCharacter = layoutManager.characterIndex(for: touchLocation,
                                                            in: textContainer,
                                                            fractionOfDistanceBetweenInsertionPoints: nil)

        for result in results {
            guard let range = Range(result.range, in: text) else { continue }
            guard result.range.contains(indexOfCharacter) else { continue }

            gesture.cancelsTouchesInView = true

            didTapDetectedResult(result, on: String(text[range]))

            return
        }
    }


    // MARK: - Init

    init(resultsColor: UIColor = .red, dataTypes: NSTextCheckingTypes) {
        dataDetector = try? NSDataDetector(types: dataTypes)

        self.resultsColor = resultsColor

        super.init(frame: .zero)

        backgroundColor = .white
        textColor = .darkText
        isUserInteractionEnabled = true
        numberOfLines = 0

        textContainer.lineFragmentPadding = 0
        textContainer.lineBreakMode = lineBreakMode
        textContainer.maximumNumberOfLines = numberOfLines

        layoutManager.addTextContainer(textContainer)

        textStorage.addLayoutManager(layoutManager)

        tapGesture.addTarget(self, action: #selector(tapped))
        addGestureRecognizer(tapGesture)
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

}

let label = FullInteractiveLabel(resultsColor: .blue, dataTypes: NSTextCheckingResult.CheckingType.link.rawValue | NSTextCheckingResult.CheckingType.date.rawValue)

label.backgroundColor = .white
label.font = .systemFont(ofSize: 14)
label.text = "My blog is located at https://rolandleth.com.\nThis is where I write from time to time.\nI wrote this class Friday, 19 January 2018."
label.numberOfLines = 3
label.sizeToFit()

label.onDetectedDataTap { result, text in
    print(result.date)
    print(result.url)
    print(text)
}

PlaygroundPage.current.needsIndefiniteExecution = true
PlaygroundPage.current.liveView = label

InteractiveLabel.swift

import UIKit

final class AttributedLabel: UILabel {

    private let dataDetector = try? NSDataDetector(types: NSTextCheckingResult.CheckingType.link.rawValue)
    private var detectedResults: [NSTextCheckingResult] {
        guard let text = attributedText?.string ?? self.text else { return [] }

        return dataDetector?.matches(in: text, range: NSRange(location: 0, length: text.count)) ?? []
    }
    private let tapGesture = UITapGestureRecognizer()
    private let layoutManager = NSLayoutManager()
    private let textContainer = NSTextContainer(size: .zero)
    private let textStorage = NSTextStorage()
    override var text: String? {
        didSet {
            guard !detectedResults.isEmpty else { return }
            guard let text = self.text else { return }

            attributedText = NSAttributedString(string: text,
                                                attributes: [.foregroundColor: textColor, .font: font])
        }
    }
    override var attributedText: NSAttributedString? {
        didSet {
            guard !detectedResults.isEmpty else { return }
            guard let oldText = self.attributedText, !oldText.string.isEmpty else {
                textStorage.setAttributedString(NSAttributedString())
                return
            }

            let mutableText = NSMutableAttributedString(attributedString: oldText)

            detectedResults.forEach {
                mutableText.addAttribute(.foregroundColor, value: linkColor, range: $0.range)
            }

            guard oldText != mutableText else {
                textStorage.setAttributedString(mutableText)
                return
            }

            attributedText = mutableText
        }
    }
    override var lineBreakMode: NSLineBreakMode {
        didSet {
            textContainer.lineBreakMode = lineBreakMode
        }
    }
    override var numberOfLines: Int {
        didSet {
            textContainer.maximumNumberOfLines = numberOfLines
        }
    }
    private let linkColor: UIColor
    private var linkTapped: (_ url: URL) -> Void = { _ in }


    // MARK: - Callbacks

    func onLinkTap(execute work: @escaping (URL) -> Void) {
        linkTapped = work
    }

    private func didTapLink(_ url: URL) {
        linkTapped(url)
    }


    // MARK: - Update

    override func layoutSubviews() {
        super.layoutSubviews()
        textContainer.size = bounds.size
    }

    @objc
    private func tapped(_ gesture: UITapGestureRecognizer) {
        gesture.cancelsTouchesInView = false
        
        let results = detectedResults
        
        guard !results.isEmpty else { return }
        guard gesture.state == .ended else { return }

        let touchLocation = gesture.location(in: gesture.view)
        let indexOfCharacter = layoutManager.characterIndex(for: touchLocation,
                                                            in: textContainer,
                                                            fractionOfDistanceBetweenInsertionPoints: nil)

        for result in results {
            guard result.range.contains(indexOfCharacter) else { continue }
            guard let url = result.url else { continue }
		
            gesture.cancelsTouchesInView = true
		
            didTapLink(url)
            
            return
        }
    }


    // MARK: - Init

    init(linkColor: UIColor = .red) {
        self.linkColor = linkColor

        super.init(frame: .zero)

        backgroundColor = .white
        textColor = .dark
        isUserInteractionEnabled = true
        numberOfLines = 0

        textContainer.lineFragmentPadding = 0
        textContainer.lineBreakMode = lineBreakMode
        textContainer.maximumNumberOfLines = numberOfLines

        layoutManager.addTextContainer(textContainer)

        textStorage.addLayoutManager(layoutManager)

        tapGesture.addTarget(self, action: #selector(tapped))
        addGestureRecognizer(tapGesture)
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

}