Custom TableViewCell with Subview whose height changes

Question

I'm using a TableView and have a custom TableViewCell that I've added a subview to.

The problem is that I need the subview's height to change sometimes and therefore, the table's contentView would have to be updated as well as the row's height.

The subview of the custom TableViewCell is represented by the yellow background.

These images show what's currently happening in my simulator.

1. On Load

2. After the event that causes the subview's height to increase

What's the best approach to take with something like this?

Should I use constraints? And if so, what kind of constraints should I use? Would I have to then reload the tableview too every time the subview's size changes?

Here is the code I'm currently using for my custom TableViewCell:

import UIKit

class CustomCell: UITableViewCell {

    var newView: UIView!

    override func awakeFromNib() {
        super.awakeFromNib()
        // Initialization code
    }

    override func setSelected(selected: Bool, animated: Bool) {
        super.setSelected(selected, animated: animated)

        // Configure the view for the selected state
    }

    override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
        super.init(style: style, reuseIdentifier: reuseIdentifier)

        self.newView = UIView(frame: self.frame)
        self.newView.backgroundColor = .yellowColor()
        self.addSubview(newView)
    }

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

    override func layoutSubviews() {
        super.layoutSubviews()
        self.newView.frame.size.width = self.frame.size.width // because self.frame.width is different than it was in the init method
   }

    func somethingHappenedThatMySubviewHasToIncreaseInHeight() {
        self.newView.frame.size.height = self.frame.size.height + 40
    }
}

Answer 1

The best approach is to use Auto Layout and self-sizing cells. Setup constraints in storyboard for your custom cell.

You will not need to reload the tableView. Each cell will automatically adjust its height, based on how much vertical space its subview takes.

For more information, see the detailed walkthrough by smileyborg in his answer to Using Auto Layout in UITableView for dynamic cell layouts & variable row heights.