Getting constraint error on updating the constraint in cellforRow - ios

Question

I have a UITableViewCell with collectionView inside it. constraint are pretty simple leading 0 , trailing 0 , top 10 and bottom 10 and height constraint of UICollection view is 160 . Connected an IBOutlet to height constraint. In cell for row I am updating the heigth constraint.
But getting error in debug
Code of cell for row is
func videoCell(for tableView:UITableView ,with indexPath:IndexPath , videos:[VideoCollectionViewCellConfigure] ) -> VideoTableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "VideoTableViewCell", for: indexPath) as! VideoTableViewCell
cell.videoConfigurators = videos
cell.collectionCellClickedBlock = self.videoCollectionCellClicked(_:_:)
if videos.count > 0 {
let video = videos[0]
cell.videoCollectionViewHeightConstraint.constant = video.height
}
cell.videoCollectionView.reloadData()
return cell
}
2018-04-16 12:42:10.815998+0530 CineBee[5280:74417] [LayoutConstraints]
Unable to simultaneously satisfy constraints.
Probably at least one of the constraints in the following list is one you don't want.
Try this:
(1) look at each constraint and try to figure out which you don't expect;
(2) find the code that added the unwanted constraint or
constraints and fix it.
(
"<NSLayoutConstraint:0x6000006878a0 UICollectionView:0x7f86109c4c00.height
== 180 (active)>",
"<NSLayoutConstraint:0x604000885870 V:[UICollectionView:0x7f86109c4c00]-(10)-| (active, names: '|':UITableViewCellContentView:0x7f8615803ca0 )>",
"<NSLayoutConstraint:0x604000888de0 V:|-(10)-
[UICollectionView:0x7f86109c4c00] (active, names: '|':UITableViewCellContentView:0x7f8615803ca0 )>",
"<NSLayoutConstraint:0x60400088dde0 'UIView-Encapsulated-Layout-Height'
UITableViewCellContentView:0x7f8615803ca0.height == 180.5 (active)>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x6000006878a0
UICollectionView:0x7f86109c4c00.height == 180 (active)>

Answer 1

Try this
override func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
var defaultHeight = /*your default height*/
if videos.count > 0 {
let video = videos[0]
return video.height + 10 + 10 // video height + top padding + bottom padding
}
return defaultHeight
}
Also remove the collectionView height constraint from the Interface builder. Now you don't have to set constraint in the cellForItemAtIndexPath.

Answer 2

According to your error report, it seems like the case I was attempting to address in this SO question. If the conflicting constraints contain UIView-Encapsulated-Layout-Height it means the conflict arises during calculating dynamic height based on autolayout. Just lower one of the vertical constraints priority to 999 - if the code works, it's ok and you are good to go.