NibBackedView.swift

//
//  NibBackedView.swift
//  Coop
//
//  Created by Jonah Burke on 1/8/19.
//  Copyright © 2019 Jonah Burke. All rights reserved.
//

import UIKit

protocol NibBackedView where Self: UIView {
    var contents: UIView? { get }
    var backingNib: UINib { get }
}

extension NibBackedView {
    var backingNib: UINib {
        let name = String(describing: type(of: self)) + "Contents"
        return UINib(nibName: name, bundle: nil)
    }

    func loadFromBackingNib() {
        backingNib.instantiate(withOwner: self, options: nil)

        if let contents = contents {
            addSubview(contents)
            contents.translatesAutoresizingMaskIntoConstraints = false
            contents.align(to: layoutMarginsGuide)
        }
    }
}