iOS8 tableviewcell height changing when rotating device in Swift - ios

Question

I am trying to use the new auto size for my tableview. Im doing this:
tableView.rowHeight = UITableViewAutomaticDimension
I have a multiline-uilabel in my UITableViewCell with some constraints that is working splendid; the height of the rows is dynamic when I enter the tableview in both landscape and portrait! Awesome!
... but when I rotate the device the rows get the basic height (i.e. 44).
I added this row:
override func willAnimateRotationToInterfaceOrientation(toInterfaceOrientation: UIInterfaceOrientation, duration: NSTimeInterval)
{
self.tableView.reloadData()
}
And the problem vanishes. But should this really be necessary? There must be a better way to fix this?
Edit:
I just found out that the same problem occurs when I'm deleting a row in the table view like this:
tableView.deleteRowsAtIndexPaths([indexPath], withRowAnimation: .Fade)
Am I missing something here? Why aint this working out of the box?
Edit again:
I've now doing like this:
self.tableView.estimatedRowHeight = 44
tableView.rowHeight = UITableViewAutomaticDimension
Then when my data is fetched from API:
self.tableView.reloadData()
self.tableView.beginUpdates()
self.tableView.endUpdates()
This seems to cover all cases I've tested so far, but it seems really hacky! Without the begin/end-updates the cells are displaying some really funky heights at the first load. (But when rotating the device, the cells adjust their heights correctly.)
This all just seems so buggy. I've not found a single guide which cover these cases correctly.

Answer 1

I had a similar issue with rotation where the entire searchbar and tableView were displaced-down on very rotation from portrait to landscape and back. See-> Swift searchBar separates from top of tableView after searchController.active during rotation:
Swift searchBar separates from top of tableView after searchController.active during rotation
I pasted your override function i.e.:
override func willAnimateRotationToInterfaceOrientation(toInterfaceOrientation: UIInterfaceOrientation, duration: NSTimeInterval)
{
self.tableView.reloadData()
}
after viewDidLoad function and my problem disappeared. Don't know why. Glenn Tisman

Answer 2

According to the WWDC session from this year, if the cell already uses Autolayout, then it is supposed to automatically resize for you. It would do this by trying to call systemLayoutSizeFittingSize:(CGSize), or if you have not used autolayout, it would try to call sizeThatFits:(CGSize)
On thing to make sure of if you're supporting iOS7 as well is that setting tableView.rowHeight and tableView.estimatedRowHeight will cause strange behavior, and you would want to conditionally call one or the other, but not both, depending on which version of iOS the app is running on.
If you're having issues with the label in particular, you might also check that you're using the new "Automatic Preferred Max Layout Width" attribute for the UILabel (if you're in a storyboard, this is under the "Attributes" inspector) and that lines is set to '0'. See the documentation for more detail. See also "Behavior of Labels" in the iOS Interface Catalog for some caveats about mixing certain behaviors of UILabel and getting strange results.
Finally, you might see what is happening in the newly added rotation methods for size classes:
-willTransitionToSize:withTransitionCoordinator:
-willTransitionToTraitCollection:withTransitionCoordinator: