UITableView inside UITableViewCell with dynamic height

Question

I need to put UITableView inside UITableViewCell with auto-layout because second table has different number of rows and one row can have different height.
This is my ViewController

class ViewController: UIViewController {

    let tableView = UITableView()
    let cellId = "firstTableCellId"

    override func viewDidLoad() {
        super.viewDidLoad()
        setupView()
        tableView.reloadData()
        view.backgroundColor = UIColor.gray
    }

    func setupView() {
        tableView.delegate = self
        tableView.dataSource = self
        tableView.separatorStyle = .none
        tableView.register(NextTable.self, forCellReuseIdentifier: cellId)
        tableView.backgroundColor = UIColor.green
        tableView.separatorStyle = .singleLine

        view.addSubview(tableView)
        view.addConstraintsWithFormat("V:|-60-[v0]-5-|", views: tableView)
        view.addConstraintsWithFormat("H:|-8-[v0]-8-|", views: tableView)
    }
}

extension ViewController: UITableViewDelegate {

}

extension ViewController: UITableViewDataSource {
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return 2
    }

    func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
        return UITableViewAutomaticDimension
    }

    func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat {
        return 80
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: cellId, for: indexPath) as! NextTable
        cell.layoutIfNeeded()
        return cell
    }
}

And NextTable which is the cell in first table

class NextTable: UITableViewCell {

    var myTableView: UITableView!
    let cellId = "nextTableCellId"

    override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
        super.init(style: style, reuseIdentifier: reuseIdentifier)
        backgroundColor = UIColor.brown
        setupView()
        myTableView.reloadData()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }

    let label: UILabel = {
        let label = UILabel()
        label.numberOfLines =  0
        label.lineBreakMode = .byWordWrapping
        label.text = "Next table:"
        label.textColor = UIColor.black
        label.sizeToFit()
        label.backgroundColor = UIColor.cyan
        return label
    }()

    func setupView() {
        myTableView = UITableView()
        myTableView.delegate = self
        myTableView.dataSource = self
        myTableView.separatorStyle = .singleLineEtched
        myTableView.backgroundColor = UIColor.blue
        myTableView.register(TableCell.self, forCellReuseIdentifier: cellId)
        myTableView.isScrollEnabled = false

        addSubview(myTableView)
        addSubview(label)
        addConstraintsWithFormat("H:|-30-[v0]-30-|", views: myTableView)
        addConstraintsWithFormat("H:|-30-[v0]-30-|", views: label)

        addConstraint(NSLayoutConstraint(item: label, attribute: .top, relatedBy: .equal, toItem: self, attribute: .top, multiplier: 1.0, constant: 15))
        addConstraint(NSLayoutConstraint(item: myTableView, attribute: .top, relatedBy: .equal, toItem: label, attribute: .bottom, multiplier: 1.0, constant: 0))
        addConstraint(NSLayoutConstraint(item: label, attribute: .bottom, relatedBy: .equal, toItem: myTableView, attribute: .top, multiplier: 1.0, constant: 0))
        addConstraint(NSLayoutConstraint(item: myTableView, attribute: .bottom, relatedBy: .equal, toItem: self, attribute: .bottom, multiplier: 1.0, constant: -15))
    }
}

extension NextTable: UITableViewDelegate {

}

extension NextTable: UITableViewDataSource {

    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return 5
    }

    func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
        return UITableViewAutomaticDimension
    }

    func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat {
        return 60
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: cellId, for: indexPath) as! TableCell
        cell.layoutIfNeeded()
        return cell
    }
}

And cell in second table

class TableCell: UITableViewCell {
    let label: UILabel = {
        let label = UILabel()
        label.numberOfLines =  0
        label.lineBreakMode = .byWordWrapping
        label.text = "Some text"
        label.textColor = UIColor.black
        label.sizeToFit()
        label.backgroundColor = UIColor.red
        return label
    }()

    override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
        super.init(style: style, reuseIdentifier: reuseIdentifier)
        backgroundColor = UIColor.yellow
        setupView()
    }

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

    func setupView(){
        addSubview(label)
        addConstraintsWithFormat("V:|-8-[v0]-8-|", views: label)
        addConstraintsWithFormat("H:|-5-[v0]-5-|", views: label)
    }
}

This is the effect of my code
There is no second table so I create new class and use it in cell as new table view

class InnerTableView: UITableView {
    override var intrinsicContentSize: CGSize {
        return self.contentSize
    }
}

And now table is show but size is too large
What can I do to show full second table without empty space at bottom of cell.

Answer 1

I added override for property in my table view:

override var intrinsicContentSize: CGSize {
    self.layoutIfNeeded()
    return self.contentSize
}

Full code for my table in table can you find on my GitHub