getCookie method Null safety

Future<Cookie?> getCookie(
  1. {required Uri url,
  2. required String name,
  3. InAppWebViewController? iosBelow11WebViewController}
)

Gets a cookie by its name for the given url.

iosBelow11WebViewController is used for getting the cookie (also session-only cookie) using JavaScript (cookie with isHttpOnly enabled cannot be found, see: https://developer.mozilla.org/en-US/docs/Web/HTTP/Cookies#restrict_access_to_cookies) from the current context of the WebView managed by that controller when you need to target iOS below 11. JavaScript must be enabled in order to work. In this case the url parameter is ignored.

NOTE for iOS below 11.0: All the cookies returned this way will have all the properties to null except for Cookie.name and Cookie.value. If iosBelow11WebViewController is null or JavaScript is disabled for it, it will try to use a HeadlessInAppWebView to get the cookie (session-only cookie and cookie with isHttpOnly enabled won't be found!).

Implementation

Future<Cookie?> getCookie(
    {required Uri url,
    required String name,
    InAppWebViewController? iosBelow11WebViewController}) async {
  assert(url.toString().isNotEmpty);
  assert(name.isNotEmpty);

  if (defaultTargetPlatform == TargetPlatform.iOS) {
    var platformUtil = PlatformUtil();
    var version = double.tryParse(await platformUtil.getSystemVersion());
    if (version != null && version < 11.0) {
      List<Cookie> cookies = await _getCookiesWithJavaScript(
          url: url, webViewController: iosBelow11WebViewController);
      return cookies
          .cast<Cookie?>()
          .firstWhere((cookie) => cookie!.name == name, orElse: () => null);
    }
  }

  Map<String, dynamic> args = <String, dynamic>{};
  args.putIfAbsent('url', () => url.toString());
  List<dynamic> cookies = await _channel.invokeMethod('getCookies', args);
  cookies = cookies.cast<Map<dynamic, dynamic>>();
  for (var i = 0; i < cookies.length; i++) {
    cookies[i] = cookies[i].cast<String, dynamic>();
    if (cookies[i]["name"] == name)
      return Cookie(
          name: cookies[i]["name"],
          value: cookies[i]["value"],
          expiresDate: cookies[i]["expiresDate"],
          isSessionOnly: cookies[i]["isSessionOnly"],
          domain: cookies[i]["domain"],
          sameSite:
              HTTPCookieSameSitePolicy.fromValue(cookies[i]["sameSite"]),
          isSecure: cookies[i]["isSecure"],
          isHttpOnly: cookies[i]["isHttpOnly"],
          path: cookies[i]["path"]);
  }
  return null;
}