IOS/Objective-C: Deallocate web view in Detail View Controller - ios

Question

I have a master table and detail view controller. The detail VC shows URLs through a web view.
If using the built in navigation of the master/detail setup, if I go back and then press a different table cell, the detail view will update the web view. This is true whether I use a UIWebView or a WKWebView.
However, within the detail view, without having to go back to the table, I want to give the user the option to view more than one url through the same web view. I am trying to do this in viewwillappear by changing the url for the request. However, the UIWebView (or alternatively WKWebView) continue to show the same url. I can't seem to get rid of the first url.
I've tried all kinds of ways to close or stop the existing web view, clear the cache, delete cookies etc. before reloading the new one but still see the same url. Would appreciate any suggestions. Here is my code and some of the things I've tried that don't work:
-(void) changeURL: (NSNumber*)param {
NSURL *testurl1=[NSURL URLWithString:#"http://www.apple.com"];
NSURL *testurl2 =[NSURL URLWithString:#"http://www.google.com"];
//if param is 1 {
_urlToLoad = testurl1;}
else {
_urlToLoad = testurl2;}
}
Edit: Method below is updateInterface, not viewWillAppear
-(void) updateInterface {
UIWebView *webView;
NSURLRequest *request=[NSURLRequest requestWithURL:_urlToLoad];
webView = nil;//This blocks the web view from loading at all for some reason I can't understand. Setting wkWebView to nil does not block loading.
[webView stopLoading];//no effect
[webView loadRequest:request];
[[NSURLCache sharedURLCache] removeCachedResponseForRequest:request];
[[NSURLCache sharedURLCache] removeAllCachedResponses];
NSString *myDomain = #"www.google.com";
for(NSHTTPCookie *cookie in [[NSHTTPCookieStorage sharedHTTPCookieStorage] cookies]) {
if([[cookie domain] isEqualToString:myDomain]) {
[[NSHTTPCookieStorage sharedHTTPCookieStorage] deleteCookie:cookie];
}
}
//wkwebview version
WKWebView *wkwebView;
WKWebViewConfiguration *wkConfig = [[WKWebViewConfiguration alloc] init];
wkwebView = nil;
wkwebView = [[WKWebView alloc] initWithFrame:self.view.frame configuration:wkConfig];
wkwebView.navigationDelegate = self;
[wkwebView loadRequest:request];
[webView addSubview:wkwebView];
CGRect webFrame = [[UIScreen mainScreen] applicationFrame];
webFrame.origin.y = 100.0; // statusbar
webFrame.origin.y -= 100.0; // statusbar 20 px cut from y of frame
webView = [[UIWebView alloc] initWithFrame:webFrame];
}

Answer 1

The UIViewController method "viewWillAppear" has the following signature in Objective-C:
- (void)viewWillAppear:(BOOL)animated
, you implemented it without any arguments.
The result is that, instead of being taken as an override of the original method defined in the superclass UIViewController, it is treated as a brand new, custom method introduced by your subclass; and unless you call it explicitly somewhere, it will never execute.
Source: SDK Reference