MessageKit/Documentation/FAQs.md

MessageKit Frequently Asked Questions

• Why doesn't the MessageInputBar appear in my controller?
• How can I remove the AvatarView from the cell?
• How can I move the AvatarView to prevent it from overlapping text in the MessageBottomLabel or CellTopLabel?
• How can I dismiss the keyboard?
• How can I get a reference to the MessageType in the MessageCellDelegate methods?
• Animations are laggy/Scrolling is not smooth/General poor performance
• How can I use MessageKit with SwiftUI

Why doesn't the MessageInputBar appear in my controller?

If you're using the MessagesViewController as a child view controller then you have to call becomeFirstResponder() on your view controller. The reason is because the MessageInputBar is the inputAccessoryView of the MessagesViewController. This means that it is not in the view hierarchy of MessagesViewController's root view.

class ParentVC: UIViewController {
    override func viewDidLoad() {
       super.viewDidLoad()
       let childVC = MessagesViewController()
       addChildViewController(childVC)
       self.view.addSubview(childVC.view)
       childVC.didMove(toParentViewController:self)
       self.becomeFirstResponder()
    }
}

How can I remove the AvatarView from the cell?

You can set the AvatarView to hidden through the configureAvatarView(_:AvatarView,for:MessageType,at:IndexPath,in:MessagesCollectionView) method of MessagesDisplayDelegate.

func configureAvatarView(_ avatarView: AvatarView, for message: MessageType, at indexPath: IndexPath, in messagesCollectionView: MessagesCollectionView) {
  avatarView.isHidden = true
}

If you would also like to remove the space the AvatarView occupies, you have to change the properties outgoingAvatarSize or incomingAvatarSize of the CellSizeCalculator object for the respective message to CGSize.zero in viewDidLoad.

if let layout = messagesCollectionView.collectionViewLayout as? MessagesCollectionViewFlowLayout {
  layout.textMessageSizeCalculator.outgoingAvatarSize = .zero
  layout.textMessageSizeCalculator.incomingAvatarSize = .zero
}

If you would like to remove the space the AvatarView occupies from all CellSizeCalculators there are convenience methods so that you do not have to specify it for each CellSizeCalculator on MessagesCollectionViewFlowLayout.

if let layout = messagesCollectionView.collectionViewLayout as? MessagesCollectionViewFlowLayout {
  layout.setMessageIncomingAvatarSize(.zero)
  layout.setMessageOutgoingAvatarSize(.zero)
}

How can I move the AvatarView to prevent it from overlapping text in the MessageBottomLabel or CellTopLabel?

If you have resized the AvatarView to be larger than the default size in MessageKit then you may notice that the AvatarView overlaps text either in the MessageBottomLabel or CallTopLabel. MessageKit allows the AvatarView to overlap this text on purpose so that users can create more complex layouts that fit their needs.

If you would like to move the AvatarView, there are convenience methods that allow you to change the horizontal or vertical positioning of the AvatarView for both incoming and outgoing messages.

if let layout = messagesCollectionView.collectionViewLayout as? MessagesCollectionViewFlowLayout {
    // set the vertical position of the Avatar for incoming messages so that the bottom of the Avatar
    // aligns with the bottom of the Message
    layout.setMessageIncomingAvatarPosition(.init(vertical: .messageBottom))

    // set the vertical position of the Avatar for outgoing messages so that the bottom of the Avatar
    // aligns with the `cellBottom`
    layout.setMessageOutgoingAvatarPosition(.init(vertical: .cellBottom))
}

There are other options provided as well so take a look at the AvatarPosition struct to see what they are.

How can I dismiss the keyboard?

The MessagesViewController needs to resign the first responder.

let controller = MessagesViewController()
controller.resignFirstResponder()

How can I get a reference to the MessageType in the MessageCellDelegate methods?

You can use UICollectionView's method indexPath(for: UICollectionViewCell) to get the IndexPath for the MessageCollectionViewCell argument. Using this IndexPath, you can then get the MessageType for this cell through the MessagesDataSource method messageForItem(at:IndexPath,in:MessagesCollectionView).

func didTapMessage(in cell: MessageCollectionViewCell) {
    guard let indexPath = messagesCollectionView.indexPath(for: cell) else { return }
    guard let messagesDataSource = messagesCollectionView.messagesDataSource else { return }
    let message = messagesDataSource.messageForItem(at: indexPath, in: messagesCollectionView)
}

Animations are laggy/Scrolling is not smooth/General poor performance

In general, if you're experiencing performance issues, you should look through the implementation of your MessageKit delegate methods like var currentSender, etc to find any expensive/blocking method calls or operations. Some delegate methods are called many times per message rendered and thus if their implementations are not efficient then performance can significantly degrade. Avoid doing blocking activities like synchronous database lookups, keychain access, networking, etc. in your MessageKit delegate methods. You should instead cache what you need.

How can I use MessageKit with SwiftUI?

MessageKit support of SwiftUI is experimental at best and there is no active work being done on adding more support