iPhone X InputAccessoryView Fix

ComposeView.swift

//
//  ComposeView.swift

import UIKit
class ComposeView: UIView {

// ........
//  Other layout code and methods
// ........
  
  
//We're adding the bottom constraint here to make sure we belong to window  
override func didMoveToWindow() {
        super.didMoveToWindow()
        if #available(iOS 11.0, *) {
            if let window = window {
                bottomAnchor.constraintLessThanOrEqualToSystemSpacingBelow(window.safeAreaLayoutGuide.bottomAnchor, multiplier: 1.0).isActive = true
            }
        }
    }
    
}