Create full page screenshots from a table view controller

UITableView+Screenshots.swift

import Foundation
import UIKit

extension UITableViewController: UIScreenshotServiceDelegate {

    public func screenshotService(_ screenshotService: UIScreenshotService, generatePDFRepresentationWithCompletion completionHandler: @escaping (Data?, Int, CGRect) -> Void) {
        let originalFrame = tableView.frame
        let originalContentOffset = tableView.contentOffset

        // Layout into an extra large frame, to force the actual heights to be calculated for all rows with estimated heights
        let oversizedContentSize = CGSize(width: tableView.contentSize.width, height: 100000)
        tableView.frame = CGRect(origin: .zero, size: oversizedContentSize)
        tableView.layoutIfNeeded()
        let actualContentSize = tableView.contentSize

        let data = NSMutableData()
        UIGraphicsBeginPDFContextToData(data, .zero, nil)
        UIGraphicsBeginPDFPageWithInfo(CGRect(origin: .zero, size: actualContentSize), nil)
        if let context = UIGraphicsGetCurrentContext() {
            tableView.contentOffset = .zero
            tableView.frame = CGRect(origin: .zero, size: actualContentSize)
            
            tableView.layoutIfNeeded()
            tableView.layer.render(in: context)
        }
        else {
            completionHandler(nil, 0, .zero)
        }
        UIGraphicsEndPDFContext()
        
        tableView.frame = originalFrame
        tableView.contentOffset = originalContentOffset

        let offsetInPDF = actualContentSize.height - originalContentOffset.y - originalFrame.height
        completionHandler(data as Data, 0, CGRect(origin: CGPoint(x: 0, y: offsetInPDF), size: self.view.frame.size))
    }
}