Conveniences for type-safe instant ion from nibs

NibLoadable.swift

//
//  NibLoadable.swift
//  Reusable
//
//  Copyright (c) <2018>, Gabriel O'Flaherty-Chan
//  All rights reserved.
//
//  Redistribution and use in source and binary forms, with or without
//  modification, are permitted provided that the following conditions are met:
//  1. Redistributions of source code must retain the above copyright
//  notice, this list of conditions and the following disclaimer.
//  2. Redistributions in binary form must reproduce the above copyright
//  notice, this list of conditions and the following disclaimer in the
//  documentation and/or other materials provided with the distribution.
//  3. All advertising materials mentioning features or use of this software
//  must display the following acknowledgement:
//  This product includes software developed by skysent.
//  4. Neither the name of the skysent nor the
//  names of its contributors may be used to endorse or promote products
//  derived from this software without specific prior written permission.
//
//  THIS SOFTWARE IS PROVIDED BY skysent ''AS IS'' AND ANY
//  EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
//  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
//  DISCLAIMED. IN NO EVENT SHALL skysent BE LIABLE FOR ANY
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//  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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//  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//


import UIKit

public protocol NibLoadable { }
extension UIView: NibLoadable { }
extension NibLoadable where Self: UIView {

  public static var nib: UINib? {
    let bundle = Bundle(for: self)
    let resource = String(describing: self)
    guard bundle.path(forResource: resource, ofType: "nib") != nil else {
      return nil
    }

    return UINib(nibName: resource, bundle: bundle)
  }

  static var reuseIdentifier: String {
    return String(describing: self)
  }


  /* Only use for final classes, as this find a nib with a name cooresponding to class name
   */
  public var viewFromNib: UIView? {
    return type(of: self).viewFromNib(owner: self)
  }

  public static func viewFromNib(owner: Any?) -> UIView? {
    let view = nib?.instantiate(withOwner: owner, options: nil).first
    return view as? UIView
  }

  public static var viewFromNib: Self? {
    let view = nib?.instantiate(withOwner: nil, options: nil).first
    return view as? Self
  }
}