Steven Deutsch
1.9 KiB
MessagesDataSource
The MessagesDataSource is responsible for returning all forms of data for the MessageCollectionViewCell. This includes the number of cells in the MessageCollectionView, the MessageType for each cell, the Avatar to be used for the AvatarView, the current Sender of each message, and finally the NSAttributedString text for the cellTopLabel and cellBottomLabel of each cell.
The MessagesDataSource requires that you implement the following 3 methods:
func currentSender() -> Sender
func messageForItem(at indexPath: IndexPath, in messagesCollectionView: MessagesCollectionView) -> MessageType
func numberOfMessages(in messagesCollectionView: MessagesCollectionView) -> Int
Providing an avatar image for AvatarView
func avatar(for message: MessageType, at indexPath: IndexPath, in messagesCollectionView: MessagesCollectionView) -> Avatar
You can use the avatar method to return an Avatar object containing the image you want to display in the AvatarView.
The Avatar type has the following 2 properties:
Avatar
public struct Avatar {
public let image: UIImage?
public var initials: String = "?"
}
If no image is provided then the AvatarView will generate a placeholder image using the specified initials of the Avatar. The default value of this method returns an Avatar with initials of "?".
Providing cellTopLabel text & cellBottomLabelText
func cellTopLabelAttributedText(for message: MessageType, at indexPath: IndexPath) -> NSAttributedString?
func cellBottomLabelAttributedText(for message: MessageType, at indexPath: IndexPath) -> NSAttributedString?
The cellTopLabelAttributedText & cellBottomLabelAttributedText methods both default to nil. If these methods return nil the label will have a size of .zero in the MessageCollectionViewCell.