WKWebView and NSURLProtocol not working

Question

When using the old UIWebView you could catch the requests by implementing a custom NSURLProtocol. I us this to handle requests that requires authentication.

I tried the same code and it doesn't work with the new WKWebView but my protocol class isn't called at all. Is someone experiencing the same problem or is there a better way of doing authentication with the WKWebView?

Without any modifications I get a 401 response in the decidePolicyForNavigationResponse delegate function. I've also tried connection to the server with a NSURLConnection and handling the authentication with a NSURLConnectionDataDelegate. That works but the stored credentials isn't picked up by the WKWebView.

Solution 1

Updated answer for iOS 11 and macOS 10.13

Since iOS 11 it is possible to declare an object that conforms to the WKURLSchemeHandler protocol and register it in the WKWebView configuration: -[WKWebViewConfiguration setURLSchemeHandler:forURLScheme:].

Old answer

WKWebView makes requests and renders content out-of-process, meaning your app does not hear the requests they make. If you are missing a functionality, now is the time to open a bug report and/or an enhancement request with Apple.

As of iOS 10.3 SDK, WKWebView is still unable to make use of custom NSURLProtocols using public APIs.

---

Enterprising developers have found an interesting method: +[WKBrowsingContextController registerSchemeForCustomProtocol:] It supposedly adds the provided scheme to a list of custom protocol handled schemes and should then work with NSURLProtocol.

Solution 2

WKWebView has a navigationDelegate property. If that delegate is set WKWebView will call the didReceiveAuthenticationChallenge method on that delegate if the method is implemented. You need to place your authentication code in this method. Example:

- (void)webView:(WKWebView *)webView didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge completionHandler:(void (^)(NSURLSessionAuthChallengeDisposition, NSURLCredential *))completionHandler {
    NSURLCredential *credential = [[NSURLCredential alloc] initWithUser:@"bob"
                                                               password:@"pass"
                                                            persistence:NSURLCredentialPersistenceNone];
    completionHandler(NSURLSessionAuthChallengeUseCredential, credential);
}

Solution 3

Try this approach: https://github.com/WildDylan/WKWebViewWithURLProtocol/tree/master/Example/WKWebViewWithURLProtocol

It may be uses private API - i'm not sure ;)

Comments

[Johan]

I tried that solution but WKWebView didn't pick up the credentials after reload

[ivanC]

sorry to hear about that ,if u got any news, pls info me

[Alex]

So, so disappointing. Has Apple given any reason for this change?

[Léo Natan]

@Alex The out-of-process makes it difficult to implement.

[karlbecker_com]

Thanks for updating this for the latest iOS SDKs! Pretty disappointing it's still not supported... hope lots of radars have been opened to make this a reality.

[Léo Natan]

This is interesting, albeit written strangely. All that is needed is calling [WKBrowsingContextController registerSchemeForCustomProtocol:@"schemes"];

[catlan]

This was added in iOS 11.

[Léo Natan]

No, HTTP protocols are not allowed. I have not looked if it might be possible using private API.

[Léo Natan]

@RamaniHitesh Your code JS nothing to do with this issue. Please don’t spam.

[Neftanic]

Did anyone tried to submit app with using private API?

[Léo Natan]

@Neftanic If you are going to use private API, at least do minimal attempt to hide it. You can search Google how to do it.