ContextLabel 1.6.0

ContextLabel 1.6.0

TestsTested
LangLanguage SwiftSwift
License MIT
ReleasedLast Release May 2019
SPMSupports SPM

Maintained by Michael Loistl, Michael Loistl.



  • By
  • Michael Loistl

Build Status

ContextLabel

A simple to use drop in replacement for UILabel written in Swift that provides automatic detection of links such as URLs, phone numbers, twitter style usernames and hashtags.

How to use it in your project

ContextLabel doesn't have any special dependencies so just include the files ContextLabel.swift in your project. Then use the ContextLabel class in replacement for UILabel.

Delegates & Closures

ContextLabel supports both, delegates and closures. Once a delegate is set, closures are ignored.

Text font

From version 1.3 you can optionally set a different font for each linkresult by returning a font within the closure or delegate:

contextLabel.textFont = { (linkResult) in
  return UIFont.systemFont(ofSize: 16)
}
func contextLabel(_ sender: ContextLabel, textFontForLinkResult linkResult: LinkResult) -> UIFont {
  return UIFont.systemFont(ofSize: 16)
}

Text colors

ContextLabel supports different colors for URLs, twitter style usernames and hashtags. By default the link text colors are set to userHandle RGB(71,90,109), hashtag RGB(151, 154, 158) and url/email/text links RGB(45, 113, 178) when using closures.

To set your own text colors, return the desired UIColor within the closure or delegate:

contextLabel.foregroundColor = { (linkResult) in
	switch linkResult.detectionType {
  case .userHandle:
    return UIColor(red: 71.0/255.0, green: 90.0/255.0, blue: 109.0/255.0, alpha: 1.0)
  case .hashtag:
    return UIColor(red: 151.0/255.0, green: 154.0/255.0, blue: 158.0/255.0, alpha: 1.0)
  case .url, .email:
    return UIColor(red: 45.0/255.0, green: 113.0/255.0, blue: 178.0/255.0, alpha: 1.0)
  case .textLink:
    return UIColor(red: 45.0/255.0, green: 113.0/255.0, blue: 178.0/255.0, alpha: 1.0)
  case .phoneNumber:
    return UIColor(red: 45.0/255.0, green: 113.0/255.0, blue: 178.0/255.0, alpha: 1.0)
  default:
    return .black
  }
}
func contextLabel(_ sender: ContextLabel, foregroundColorForLinkResult linkResult: LinkResult) -> UIColor {
  return sender.foregroundColor(linkResult)
}

Highlighted text colors

If there is no UIColor returned from foregroundHighlightedColor, an alpha of 0.5 is applied to the set text color when a link is detected.

To set your own text highlight colors, return the desired UIColor within the closure or delegate:

contextLabel.foregroundHighlightedColor = { (linkResult) in
  return .lightGray
}
func contextLabel(_ sender: ContextLabel, foregroundHighlightedColorForLinkResult linkResult: LinkResult) -> UIColor {
  return sender.foregroundHighlightedColor(linkResult)
}

Underline style

By default detected links are not underlined.

To set your own underline style, return the desired NSUnderlineStyle within the closure or delegate:

contextLabel.underlineStyle = { (linkResult) in
  return .styleNone
}
func contextLabel(_ sender: ContextLabel, underlineStyleForLinkResult linkResult: LinkResult) -> NSUnderlineStyle
  return sender.underlineStyle(linkResult)
}

Modify attributed string

From version 1.3 you can also modify the attributed string before it gets finally applied to the label via the following closure or delegate:

contextLabel.modifiedAttributedString = { (attributedString) in
  var _attributedString = attributedString

  // Modify attributes

  return _attributedString
}
func contextLabel(_ sender: ContextLabel, modifiedAttributedString attributedString: NSAttributedString) -> NSAttributedString {
  var _attributedString = modifiedAttributedString

  // Modify attributes

  return _attributedString
}

Selection handling

When tapping the label, the closure didTouch: (TouchResult) -> Void will be called for each touch state:

didTouch: { [weak self] (touchResult) in
    switch touchResult.state {
    case .began:
        // Do something
    case .ended:
        // Do something
    default:
        break
    }
}

From version 1.3.0 you can alternativly implement the delegate:

func contextLabel(_ sender: ContextLabel, didTouchWithTouchResult touchResult: TouchResult) {
    switch touchResult.state {
    case .began:
        // Do something
    case .ended:
        // Do something
    default:
        break
    }
}

The touch behaviour changed from version 1.2.0.

The touchResult includes everything you need to take action on the selected string.

public struct TouchResult {
    public let linkResult: LinkResult?
    public let touches: Set<UITouch>
    public let event: UIEvent?
    public let state: UIGestureRecognizerState
}
public struct LinkResult {
    public let detectionType: ContextLabel.LinkDetectionType
    public let range: NSRange
    public let text: String
    public let textLink: TextLink?
}
public enum LinkDetectionType {
    case none
    case userHandle
    case hashtag
    case url
    case email
    case textLink
    case phoneNumber
}

Did copy

To allow copying of text into pastboard via longpress set contextLabel.canCopy = true and implement the following closure or delegate:

contextLabel.didCopy = { (text) in
  
}
func contextLabel(_ sender: ContextLabel, didCopy text: String?) {
  
}

Text links

ContextLabel automatically recognizes words starting with # and @ as well as manually defined text links.

A text link is defined at the minimum by a string ”text link” and an action which is a closure that gets called when the user touches the defined text. From version 0.3.1, all occurencies of a given text are recognized within the label text. To limit the recognition within the label text, an optional range can be set when initializing a TextLink.

TextLink(text: String, range: NSRange? = nil, options: NSString.CompareOptions = [], action: @escaping ()->())

Use of cache

When setting the text, ContextLabel generates an instance of ’ContextLabelData’ which is a NSObject subclass that can be persisted in order to enable reuse for unchanged data.

’ContextLabelData’ holds the actual attributedString, the linkRangeResults and a userInfo dictionary which can be used to compare against the model data to see if it’s still valid.

if let cachedContextLabelData: ContextLabelData =  {
	// Set cached contextLabelData
	contextLabel.contextLabelData = cachedTextContextLabelData
} else {
	// Set label text
	contextLabel.text = text

	// Cache contextLabelData that has been generated from contextLabel
	cacheContextLabelData(contextLabel.contextLabelData)
}          

Maintenance Expectations

While contributions are always welcome, do not expect a lot of feature evolution beyond the current state. Feel free to fork this library or open pull requests if you'd like to add new features or need fixes and Swift updates.

License & Credits

ContextLabel is is released under the MIT License. ContextLabel was inspired by KILabel (https://github.com/Krelborn/KILabel).

Contact