Tableview height based on its content - uitableview

Question

I want to create table view's that are constrained to their super view's with a top,left, and right margin, but a lessThanOrEqualTo bottom margin. This way if the tale view's content is taller than its super view it will be constrained to the bottom margin and scroll. But if its e.g. only 3 cells, and the cells have their own internally consistent constraints, the tableview will be e.g. 200 pts tall and their will be space between it and the super view bottom margin. So far when trying this, if i don't specify the bottom constraint or set it as lessThanOrEqual to I see an ambiguous layout warning in the visual debugger.

Answer 1

Tableview height based on its content with UITableViewAutomaticDimension
//make bottom margin constraint #IBOutlet for tableView
#IBOutlet weak var bottomConstraint: NSLayoutConstraint!
#IBOutlet weak var tableView: UITableView!
var rowCount = 3
override func viewDidLoad() {
super.viewDidLoad()
tableView.rowHeight = UITableViewAutomaticDimension
make outlet connection to a tableView bottom constraint
func tableView(_ tableView: UITableView, heightForFooterInSection section: Int) -> CGFloat {
return CGFloat.leastNormalMagnitude
}
var height: [CGFloat] = [0]
func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
let indexRowNo = indexPath.row
//will give you cell height for indexPath
let frame = tableView.rectForRow(at: indexPath)
//if cell height already exists in height update value else append
if self.height.count-1 >= indexRowNo{
height.remove(at: indexRowNo)
height.insert(frame.size.height, at: indexRowNo)
}else{
height.append(frame.size.height)
}
if indexPath.row == (tableView.indexPathsForVisibleRows?.last)?.row {
//remove old cell heights if now tableView has less noOfCell after reloadData
if self.height.count >= rowCount{
for _ in rowCount..<self.height.count{
self.height.removeLast()
}
}
}
// total Height for tableView
let totalHeight: CGFloat = height.reduce(0, +)
//e.g. - less/greater ThanOrEqualTo bottom margin conditions
let viewTotalHeight = self.view.frame.height - 80
if totalHeight <= viewTotalHeight{
let value = (self.view.frame.height) - (totalHeight + 10)
self.bottomConstraint.constant = value
self.tableView.isScrollEnabled = false
}else{
self.bottomConstraint.constant = 0
self.tableView.isScrollEnabled = true
}
}