1#!/usr/bin/env swift
2/// Save a web page as a Safari webarchive.
3///
4/// Usage: save_safari_webarchive [URL] [OUTPUT_PATH]
5///
6/// This will save the page to the desired file, but may fail for
7/// several reasons:
8///
9///   - the web page can't be loaded
10///   - the web page returns a non-200 status code
11///   - there's already a file at that path (it won't overwrite an existing
12///     webarchive)
13///
14/// For a detailed explanation of the code in this script, see
15/// https://alexwlchan.net/2024/creating-a-safari-webarchive/
16///
17/// The canonical copy of this script lives in GitHub, see
18/// https://github.com/alexwlchan/safari-webarchiver
19
20import WebKit
21
22let SCRIPT_VERSION = "1.0.1"
23
24/// Print an error message and terminate the process if there are
25/// any errors while loading a page.
26class ExitOnFailureDelegate: NSObject, WKNavigationDelegate {
27  var urlString: String
28
29  init(_ urlString: String) {
30    self.urlString = urlString
31  }
32
33  func webView(
34    _: WKWebView,
35    didFail: WKNavigation!,
36    withError error: Error
37  ) {
38    fputs("Failed to load \(self.urlString): \(error.localizedDescription)\n", stderr)
39    exit(1)
40  }
41
42  func webView(
43    _: WKWebView,
44    didFailProvisionalNavigation: WKNavigation!,
45    withError error: Error
46  ) {
47    fputs("Failed to load \(self.urlString): \(error.localizedDescription)\n", stderr)
48    exit(1)
49  }
50
51  func webView(
52    _: WKWebView,
53    decidePolicyFor navigationResponse: WKNavigationResponse,
54    decisionHandler: (WKNavigationResponsePolicy) -> Void
55  ) {
56    if let httpUrlResponse = (navigationResponse.response as? HTTPURLResponse) {
57      if httpUrlResponse.statusCode != 200 {
58        fputs("Failed to load \(self.urlString): got status code \(httpUrlResponse.statusCode)\n", stderr)
59        exit(1)
60      }
61    }
62
63    decisionHandler(.allow)
64  }
65}
66
67extension WKWebView {
68
69  /// Load the given URL in the web view.
70  ///
71  /// This method will block until the URL has finished loading.
72  func load(_ urlString: String) {
73    let delegate = ExitOnFailureDelegate(urlString)
74    webView.navigationDelegate = delegate
75
76    if let url = URL(string: urlString) {
77      let request = URLRequest(url: url)
78      self.load(request)
79
80      while (self.isLoading) {
81        RunLoop.main.run(until: Date(timeIntervalSinceNow: 0.1))
82      }
83    } else {
84      fputs("Unable to use \(urlString) as a URL\n", stderr)
85      exit(1)
86    }
87  }
88
89  /// Save a copy of the web view's contents as a webarchive file.
90  ///
91  /// This method will block until the webarchive has been saved,
92  /// or the save has failed for some reason.
93  func saveAsWebArchive(savePath: URL) {
94    var isSaving = true
95
96    self.createWebArchiveData(completionHandler: { result in
97      do {
98        let data = try result.get()
99        try data.write(
100          to: savePath,
101          options: [Data.WritingOptions.withoutOverwriting]
102        )
103        isSaving = false
104      } catch {
105        fputs("Unable to save webarchive file: \(error.localizedDescription)\n", stderr)
106        exit(1)
107      }
108    })
109
110    while (isSaving) {
111      RunLoop.main.run(until: Date(timeIntervalSinceNow: 0.1))
112    }
113  }
114}
115
116if CommandLine.arguments.count == 2 && CommandLine.arguments[1] == "--version" {
117  let filename = (CommandLine.arguments[0] as NSString).lastPathComponent
118  print("\(filename) \(SCRIPT_VERSION)")
119  exit(0)
120}
121
122guard CommandLine.arguments.count == 3 else {
123  fputs("Usage: \(CommandLine.arguments[0]) <URL> <OUTPUT_PATH>\n", stderr)
124  exit(1)
125}
126
127let urlString = CommandLine.arguments[1]
128let savePath = URL(fileURLWithPath: CommandLine.arguments[2])
129
130let webView = WKWebView()
131
132webView.load(urlString)
133webView.saveAsWebArchive(savePath: savePath)
134
135print("Saved webarchive to \(savePath)")