Abstract class allowing UIViews to be programmatically initialized while using IB internally for layout

IBLoadableView.swift

import UIKit

/// Allows loading view from Nibs named the same as the class.
class IBLoadableView: UIView {
    
    fileprivate var view: UIView!
    
    convenience init() {
        self.init(frame: CGRect.zero)
    }
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        xibSetup()
        setup()
    }
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        xibSetup()
        setup()
    }
    
}

// MARK: - Setup

extension IBLoadableView {
    
    /// Any setup after initiaization can be done here. Always call super at some point.
    func setup() {
        backgroundColor = .clear
    }
    
}

// MARK: - XIB Loading 

fileprivate extension IBLoadableView {
    
    func xibSetup() {
        view = loadViewFromNib(named: nameOfClass)
        
        addSubview(view)
        view.layoutWithEdgesEqualToSuperView()
        awakeFromNib()
    }
    
    func loadViewFromNib(named name: String) -> UIView {
        let bundle = Bundle(for: type(of: self))
        
        if nibExists(withName: name, in: bundle) {
            let nib = UINib(nibName: name, bundle: bundle)
            let view = nib.instantiate(withOwner: self, options: nil).first as! UIView
            
            return view
        } else if let superclass = superclass {
            return loadViewFromNib(named: superclass.nameOfClass)
        } else {
            fatalError("No NIB found: \(nameOfClass)")
        }
    }
    
    func nibExists(withName name: String, in bundle: Bundle) -> Bool {
        return bundle.path(forResource: name, ofType: "nib") != nil
    }
    
}