Back Button Code for Checkpoint #32

gistfile1.txt

- (void) updateBackButton {
    if ([self.webView canGoBack]) {
        if (!self.navigationItem.leftBarButtonItem) {
            [self.navigationItem setHidesBackButton:YES animated:NO];
            UIBarButtonItem *backButton = [[UIBarButtonItem alloc] initWithTitle:@"< Login" style:UIBarButtonItemStylePlain target:self action:@selector(backButtonClicked)];
            self.navigationItem.leftBarButtonItem = backButton;
        } 
    } else {
        [self.navigationItem setLeftBarButtonItem:nil animated:YES];
    }
}

- (void) backButtonClicked {
    if ([self.webView canGoBack]) {
        [self.webView goBack];
    }
}

- (void)webViewDidFinishLoad:(UIWebView *)webView {
    [self updateBackButton];
}