Read More/Less with Swift 3

Question

I want to add \"Read more\" at the end of the paragraph. When I click on the \"Read more\" text, it should be expand and display \"Less\" a

Answer 1

I have done it with trimming the string.

we can compare the string characters length by .count and we can hide read more button if there are less only very few characters in the string.

And removed the last word after trimming to ensure that no visible words are cut off. Then added "...." at the end

        var trimData = ""

        if eventData.eventDescription.count > 500 {
            cell.readMoreLabel.isHidden = false

            if !readMore {

                if eventData.eventDescription.count > 500 {

                    trimData = String(eventData.eventDescription.prefix(500))

                    trimData = trimData.components(separatedBy: " ").dropLast().joined(separator: " ")

                    trimData = trimData+"...."
                } else {
                    trimData = eventData.eventDescription
                }

                cell.readMoreLabel.attributedText = NSAttributedString(string: "Read More", attributes:
                    [.underlineStyle: NSUnderlineStyle.styleSingle.rawValue])



            } else {
                trimData = eventData.eventDescription
                cell.readMoreLabel.attributedText = NSAttributedString(string: "Read Less", attributes:
                    [.underlineStyle: NSUnderlineStyle.styleSingle.rawValue])
            }

        } else {
            trimData = eventData.eventDescription
             cell.readMoreLabel.isHidden = true
        }

Answer 2

• Create an outlet for height constraint of your messageLabel
• Set top layout of your "Read more" button to messageLabel

• On clicking "Read more" button increase height constraint constant, on clicking "Read less" decrease height constraint constant.

  @IBOutlet weak var btn: UIButton!
  
  @IBOutlet weak var lblHeight: NSLayoutConstraint!
  
  var isLabelAtMaxHeight = false
  
  @IBAction func btnAction(_ sender: Any) {
      if isLabelAtMaxHeight {
          btn.setTitle("Read more", for: .normal)
          isLabelAtMaxHeight = false
          lblHeight.constant = 70
      }
      else {
          btn.setTitle("Read less", for: .normal)
          isLabelAtMaxHeight = true
          lblHeight.constant = getLabelHeight(text: yourSummaryText, width: view.bounds.width, font: yourSummaryLabel.font)
      }
  }
  

Get height of a text

    func getLabelHeight(text: String, width: CGFloat, font: UIFont) -> CGFloat {
        let lbl = UILabel(frame: .zero)
        lbl.frame.size.width = width
        lbl.font = font
        lbl.numberOfLines = 0
        lbl.text = text
        lbl.sizeToFit()

        return lbl.frame.size.height
    }