WKWebview could not load asset files because of Authorization - ios

Question

I have a WKWebview applying AWS Cognito.
Every request to the server has to be added Authorization into request header.
let access_token = "Bearer \(key)"
let header: [String: String] = [
"Authorization": access_token
]
if let url = URL(string: "https://myserverdomain.amazonaws.com/api/v3/graphs?date=2020-08-28") {
var request: URLRequest = URLRequest(url: url)
request.allHTTPHeaderFields = header
wkWebview.load(request)
}
With this code, I already can load the page content but CSS in the page. I checked with chrome (using ModHeader chrome extension to add header) and it works, show correctly, also Android.
I inspected by Chrome and the CSS link in < head > tag like this, it is not the same folder with the HTML file (I don't know if it is the reason).
<link rel="stylesheet" type="text/css" href="https://myserverdomain.amazonaws.com/assets/graphs/style.css"></script>
I can load the css content only with the code:
let access_token = "Bearer \(key)"
let header: [String: String] = [
"Authorization": access_token
]
if let url = URL(string: "https://myserverdomain.amazonaws.com/assets/graphs/style.css") {
var request: URLRequest = URLRequest(url: url)
request.allHTTPHeaderFields = header
wkWebview.load(request)
}
UIWebview was deprecated, Is there any way to set WKWebview with a global header as always?
Thank you for your help.

Answer 1

You can redirect all webview's requests to your URLSession with your configuration. To do that you can register your custom URLProtocol for https scheme. There is a hack for WKWebView to intercept url requests with WKBrowsingContextController private class and your URLProtocol implementation e.g.:
class MiddlewareURLProtocol : URLProtocol {
static let handledKey = "handled"
lazy var session : URLSession = {
// Config your headers
let configuration = URLSessionConfiguration.default
//configuration.httpAdditionalHeaders = ["Authorization" : "..."]
return URLSession(configuration: configuration, delegate: self, delegateQueue: nil)
}()
var sessionTask : URLSessionTask?
override var task: URLSessionTask? {
return sessionTask
}
static func registerClass() {
let sel = NSSelectorFromString("registerSchemeForCustomProtocol:")
if let cls = NSClassFromString("WKBrowsingContextController") as? NSObject.Type, cls.responds(to:sel) {
// Register https protocol
cls.perform(sel, with: "https")
}
URLProtocol.registerClass(Self.self)
}
override class func canInit(with request: URLRequest) -> Bool {
return URLProtocol.property(forKey: Self.handledKey, in: request) == nil
}
override class func canonicalRequest(for request: URLRequest) -> URLRequest {
return request
}
override class func requestIsCacheEquivalent(_ a: URLRequest, to b: URLRequest) -> Bool {
super.requestIsCacheEquivalent(a, to: b)
}
override func startLoading() {
let redirect = (request as NSURLRequest).mutableCopy() as! NSMutableURLRequest
URLProtocol.setProperty(true, forKey: Self.handledKey, in: redirect)
sessionTask = session.dataTask(with: redirect as URLRequest)
task?.resume()
}
override func stopLoading() {
task?.cancel()
}
}
extension MiddlewareURLProtocol : URLSessionDataDelegate {
func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?) {
if let err = error {
client?.urlProtocol(self, didFailWithError: err)
}
else {
client?.urlProtocolDidFinishLoading(self)
}
}
func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive response: URLResponse, completionHandler: #escaping (URLSession.ResponseDisposition) -> Void) {
client?.urlProtocol(self, didReceive: response, cacheStoragePolicy: .allowed)
completionHandler(.allow)
}
func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive data: Data) {
client?.urlProtocol(self, didLoad: data)
}
func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, willCacheResponse proposedResponse: CachedURLResponse, completionHandler: #escaping (CachedURLResponse?) -> Void) {
completionHandler(proposedResponse)
}
func urlSession(_ session: URLSession, task: URLSessionTask, willPerformHTTPRedirection response: HTTPURLResponse, newRequest request: URLRequest, completionHandler: #escaping (URLRequest?) -> Void) {
let redirect = (request as NSURLRequest).mutableCopy() as! NSMutableURLRequest
Self.removeProperty(forKey: Self.handledKey, in: redirect)
client?.urlProtocol(self, wasRedirectedTo: redirect as URLRequest, redirectResponse: response)
self.task?.cancel()
let error = NSError(domain: NSCocoaErrorDomain, code: CocoaError.Code.userCancelled.rawValue, userInfo: nil)
client?.urlProtocol(self, didFailWithError: error)
}
}
Just register your protocol on app start to handle all requests:
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
MiddlewareURLProtocol.registerClass()
...
}
NOTE: To prevent Apple static checks for private classes you can store class names in the array:
let className = ["Controller", "Context", "Browsing", "WK"].reversed().joined()