Dynamic Cell Sizing:Overriding Xcode storyboard constraints

Question

By right, this should give a adjusted cell based on the content.However, the height of my cell is still based on the storyboard property and is there a way to let the height adjust dynamically by overriding the storyboard property?

func collectionView(_ collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
sizeForItemAt indexPath: IndexPath) -> CGSize {
if let chatsText = chats[indexPath.row].message {
    let size = CGSize(width: 250, height: 1000)
        let options =   NSStringDrawingOptions.usesFontLeading.union(.usesLineFragmentOrigin)
        let estimatedFrame = NSString(string: chatsText).boundingRect(with: size, options: options, attributes: [NSAttributedStringKey.font : UIFont.systemFont(ofSize: 18)], context: nil)
        return CGSize(width: view.frame.width, height: estimatedFrame.height + 20)
    }

    return CGSize(width: view.frame.width, height: 200)
}
}

 func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell{
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellIdentifierA, for: indexPath) as! ChatCollectionViewCell
 //   cell.messageReceived.text = chats.reversed()[indexPath.row].message
     let senderIDNumber = Auth.auth().currentUser?.uid
    if chats[indexPath.row].senderID == senderIDNumber {
    cell.messageSend.text = chats[indexPath.row].message
        if let chatsText = chats[indexPath.row].message {
            let size = CGSize(width: 250, height: 1000)
            let options = NSStringDrawingOptions.usesFontLeading.union(.usesLineFragmentOrigin)
            let estimatedFrame = NSString(string: chatsText).boundingRect(with: size, options: options, attributes: [NSAttributedStringKey.font : UIFont.systemFont(ofSize: 18)], context: nil)
            cell.messageSend.frame = CGRect(x:0,y:0,width:250 + 16, height:estimatedFrame.height + 20)

         //showOutgoingMessage(text: chats[indexPath.row].message)
    }
    else {
   /* cell.messageReceived.text = chats[indexPath.row].message */
    }
    }
     return cell
    }

Answer 1

Just after you set your chats array in your code add the following line :

yourCollectionViewName.reloadData()

You probably pass into your sizeForItemAtIndexPath method before setting your array of chat. reloadData method will reload your collectionView and calculate cell size again.

Answer 2

maybe you forget to set collection view's delete to your layout object. in this case, you've confirmed flow layout protocol already:

UICollectionViewDelegateFlowLayout

two ways to set collection view's delegate:

1st. by programming:

collectionView.delegate = self // if your view controller confirms UICollectionViewDelegateFlowLayout

2nd. in storyboard: control and drag to the view controller

BTW, if this is not the right ans, please upload your repo to public, like Github, we would help you fix it.