Extension that make easier to add UIView or UIViewController as Header of UITableView

UITableView+.swift

//
//  UITableView+.swift
//
//  Created by Joao Reichert on 18/02/19.
//  Copyright © 2019 Reichert. All rights reserved.
//

import UIKit

extension UITableView {
    
    /// Add Header from View with Auto Layout
    func addHeader(from view: UIView) {
        let container = UIView()
        container.translatesAutoresizingMaskIntoConstraints = false
        container.sv(view)
        
        view.snp.makeConstraints { (make) in
            make.edges.equalTo(container)
        }
        
        self.tableHeaderView = container
        
        container.snp.makeConstraints { (make) in
            make.centerX.equalTo(self.snp.centerX)
            make.width.equalTo(self.snp.width)
            make.top.equalTo(self.snp.top)
        }
        
        self.tableHeaderView?.layoutIfNeeded()
        let temp = self.tableHeaderView
        self.tableHeaderView = temp
    }
    
    /// Add new header do UITableView from viewController
    func addHeader(from headerViewController: UIViewController, inside viewController: UIViewController) {
        
        viewController.add(headerViewController)
        self.addHeader(from: headerViewController.view)
    }
    
    /*
    To update the header frame on device rotation
    update layout in viewWillTransitionToSize, but do it in the next draw loop (by wrapping with Dispatch.main.async), since layoutIfNeed() needs to know the correct parent frame first:
    
    override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
        super.viewWillTransition(to: size, with: coordinator)
        DispatchQueue.main.async {
            self.tableView.tableHeaderView?.layoutIfNeeded()
            self.tableView.tableHeaderView = self.tableView.tableHeaderView
        }
    }
     */
}