Creating PDFs From WKWebView

Creating PDFs From WKWebView

//
//  ViewController.swift
//  WebKitPDFAndImageDemo
//
//  Created by Aryaman Sharda on 2/18/23.
//

import UIKit
import WebKit

class ViewController: UIViewController {
    private lazy var webView: WKWebView = {
        // We'll go ahead and use the default configuration here. Some cool options here, but not in scope.
        let webView = WKWebView(frame: .zero, configuration: WKWebViewConfiguration())

        // This will be used to determine when the web page has fully loaded.
        webView.navigationDelegate = self

        view.addSubview(webView)
        webView.pinToSuperview()
        return webView
    }()

    override func viewDidLoad() {
        super.viewDidLoad()
        loadURL(from: "https://www.digitalbunker.dev")
    }

    private func loadURL(from string: String) {
        guard let url = URL(string: string) else {
            return
        }

        webView.load(URLRequest(url: url))
    }

    private func saveAsPDF(title: String?) {
        let pdfConfiguration = WKPDFConfiguration()

        /// Using `webView.scrollView.frame` allows us to capture the entire page, not just the visible portion
        pdfConfiguration.rect = CGRect(x: 0, y: 0, width: webView.scrollView.contentSize.width, height: webView.scrollView.contentSize.height)

        webView.createPDF(configuration: pdfConfiguration) { result in
            switch result {
            case .success(let data):
                guard let downloadsDirectory = FileManager.default.urls(for: .downloadsDirectory, in: .userDomainMask).first else {
                    return
                }

                do {
                    let savePath = downloadsDirectory.appendingPathComponent(title ?? "PDF").appendingPathExtension("pdf")
                    try data.write(to: savePath)

                    print("Successfully created and saved PDF at \(savePath)")
                } catch let error {
                    print("Could not save pdf due to \(error.localizedDescription)")
                }

            case .failure(let failure):
                print(failure.localizedDescription)
            }
        }
    }
}

extension ViewController: WKNavigationDelegate {
    func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
        // The web view has finished loading the resource, we can now create a PDF
        saveAsPDF(title: webView.title)
    }
}

extension UIView {
    func pinToSuperview() {
        guard let superview else { return }

        translatesAutoresizingMaskIntoConstraints = false

        NSLayoutConstraint.activate([
            topAnchor.constraint(equalTo: superview.topAnchor),
            bottomAnchor.constraint(equalTo: superview.bottomAnchor),
            leadingAnchor.constraint(equalTo: superview.leadingAnchor),
            trailingAnchor.constraint(equalTo: superview.trailingAnchor)
        ])
    }
}