Smarty way to init xib views inside other xibs

ReusableXibView.swift

import UIKit

/// thanks to Badoo
/// https://github.com/badoo/Chatto/blob/master/ChattoAdditions/Source/Input/ReusableXibView.swift
@objc open class ReusableXibView: UIView {

    func loadViewFromNib() -> UIView {
        let bundle = Bundle(for: type(of: self))
        let nib = UINib(nibName: type(of: self).nibName(), bundle: bundle)
        let view = nib.instantiate(withOwner: nil, options: nil).first as! UIView
        return view
    }

    override open func awakeAfter(using aDecoder: NSCoder) -> Any? {
        if self.subviews.count > 0 {
            return self
        }

        let bundle = Bundle(for: type(of: self))
        if let loadedView = bundle.loadNibNamed(type(of: self).nibName(), owner: nil, options: nil)?.first as? UIView {
            loadedView.frame = frame
            loadedView.autoresizingMask = autoresizingMask
            loadedView.translatesAutoresizingMaskIntoConstraints = translatesAutoresizingMaskIntoConstraints
            for constraint in constraints {
                let firstItem = constraint.firstItem === self ? loadedView : constraint.firstItem
                let secondItem = constraint.secondItem === self ? loadedView : constraint.secondItem
                loadedView.addConstraint(NSLayoutConstraint(item: firstItem as Any, attribute: constraint.firstAttribute, relatedBy: constraint.relation, toItem: secondItem, attribute: constraint.secondAttribute, multiplier: constraint.multiplier, constant: constraint.constant))
            }
            return loadedView
        } else {
            return nil
        }
    }

    class func nibName() -> String {
        assert(false, "Must be overriden")
        return ""
    }
}