How To Clear A UIWebView

Question

I am very new to the whole programming business, and was wondering if there is any way to clear the contents of a UIWebView in iphone programming, so that the l

Answer 1

Swift 4.0 , XCODE 9

webView.loadRequest(URLRequest.init(url: URL.init(string: "about:blank")!))

Answer 2

Try setting the URL to about:blank and reload the page.

Answer 3

Just load an empty html string into it

[self.webView loadHTMLString:@"" baseURL:nil];

Answer 4

Swift, Xcode 7 beta 5

webView.loadRequest(NSURLRequest(URL: NSURL(string: "about:blank")!))

Answer 5

Answer extension for documentation purposes to maybe help someone else:

I had the same desire (clear content before loading next url) but had a UIWebView delegate set to receive webviewDidFinishLoad:(UIWebView)webview message and update another part of UI in response.

Problem: the call to clear the content to also called delegate method, so getting false-hits (that is, getting call when clear is done, too, but delegate is coded to expect call only when real content is loaded).

Solution: use a known URL for clear, and have webviewDidFinishLoad: ignore calls made when that URL is finished:

- (void) startLoadOfNextURL:(NSURL*)url
{
    // clear:
    [self.webView loadHTMLString:@"" baseURL:nil];

    // Load real next URL
    NSURLRequest* request = [NSURLRequest requestWithURL:url];
    [self.webView loadRequest:request];
}


- (void)webViewDidFinishLoad:(UIWebView *)webView
{
    NSLog(@"WebView finished loading: %@", webView);
    if ([self.webView.request.URL.absoluteString isEqualToString:@"about:blank"]) {
        NSLog(@"  This is Blank. Ignoring as false event.");
    }
    else {
        NSLog(@"  This is a real url");
        [self updateUIInSomeWay];
    }
}

Note: using this:

    [self.webView loadHTMLString:@"about:blank" baseURL:nil];

actually causes the words "about:blank" to appear as text in the webview's content pane!

Final complication: In practice, with my two [webview load...] calls so close together, I was finding that instead of a "loaded" event for the clear, the webview was actually canceling it in favor of the second request and calling webView: didFailLoadWithError: for the first load request. Thus, I had to put similar code in that event:

- (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error
{
    NSLog(@"WebView error on: %@", webView);
    NSLog(@"Error is: %@", error);

    NSURL* failingURL = [error.userInfo objectForKey:@"NSErrorFailingURLKey"];
    if ([failingURL.absoluteString isEqualToString:@"about:blank"]) {
        NSLog(@"  This is Blank. Ignoring.");
    }
    else {
        NSLog(@"  This is a real URL.");
        [self doSomethingAboutError];
    }
}

Answer 6

Same answer in Swift 4.2, xCode 10

if let clearURL = URL(string: "about:blank") {
   myWebView.loadRequest(URLRequest(url: clearURL))
}