Swift JSQMessagesViewController name on top - uicollectionview

Question

I am displaying the sender name of the receiver. However, I don't want to display the name on every single text that the person sends. For example, if he/she sends a a message consecutively, I just want it to display the name on top of the first message. I'll provide a screenshot of my chat here:
In other words, I just want it to display the name of the user on the very 'first' message he/she sends. I tried to solve this issue, in the attributedTextForMessageBubbleTopLabelAt with no luck.
I have tried to check if the senderId of the previous message is equal to the previous senderId - and then somehow find out if it can be shown or not. But, this has resulted in many, many failed attempts with optional errors, index out of range, and just simply not working solutions.
This is the code I have right now:
let message = messages[indexPath.item]
switch message.senderId {
case FIRAuth.auth()!.currentUser!.uid:
return nil
break
default:
guard let senderDisplayName = message.senderDisplayName else {
assertionFailure()
return nil
}
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.alignment = NSTextAlignment.left
let attributedString = NSAttributedString(string: message.senderDisplayName,
attributes: [
NSParagraphStyleAttributeName: paragraphStyle,
NSBaselineOffsetAttributeName: NSNumber(value: 0)
])
return attributedString
break
}

Answer 1

This is a difficult problem at first to solve when you first look at it. What we need to do is determine if a message is the first in a set of messages. So I created a function to determine wether or not a message is the first one sent by that person.
private func firstMessageInSet(indexOfMessage: IndexPath) -> Bool {
return messages[safe: indexOfMessage.item - 1]?.senderId() == messages[safe: indexOfMessage.item]?.senderId()
}
it simply checks the pervious message's senderId to see if it is the same as the current message.
Then just call that guy in this method:
override func collectionView(_ collectionView: JSQMessagesCollectionView!, attributedTextForMessageBubbleTopLabelAt indexPath: IndexPath!) -> NSAttributedString! {
guard let message = messages[safe: indexPath.item] else { return nil }
return firstMessageInSet(indexOfMessage: indexPath) ? nil : NSAttributedString(string: message.senderDisplayName)
}
This will check if its the first in the set and if it is return the senderDisplayName. Now this is using short hand but is eventually the same as
if firstMessageInSet(indexOfMessage: indexPath) {
return NSAttributedString(string: message.senderDisplayName)
} else {
return nil
}
Hope that that helps you good luck with things 🤖