         
         let du_collectionView = collectionView as! DUMessageCollectionView
         let du_collectionViewLayout = du_collectionView.collectionViewLayout as! DUMessageCollectionViewFlowLayout
+        
+        var messageItem = messageData(atIndexPath: indexPath, forCollectionView: du_collectionView)
         
         var cellIdentifier: String = ""
         if messageItem.isOutgoingMessage {

// MARK: Class method
public extension DUMessagesViewController {
    static var nib: UINib { return UINib.init(nibName: self.nameOfClass, bundle: NSBundle(identifier: Constants.bundleIdentifier)) }
}



    /// Scroll to the bottom of message collection view
    final public func scrollToBottom(animated animated: Bool) {
        guard collectionView?.numberOfSections() != 0 else { return }
        guard collectionView?.numberOfItemsInSection(0) != 0 else { return }
        
        let lastIndexPath: NSIndexPath = NSIndexPath(forItem: collectionView!.numberOfItemsInSection(0) - 1, inSection: 0)
        scrollTo(indexPath: lastIndexPath, animated: animated)
