shouldStartLoadWithRequest doesn't run stringByEvaluatingJavaScriptFromString method

Question

I am trying to run the code below in webview's shouldStartLoadWithRequest delegate method but it doesn't make any changes.

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType{
    NSLog(@"webView shouldStartLoadingWithRequest");
    [self.webView stringByEvaluatingJavaScriptFromString:[NSString stringWithFormat:@"document.execCommand('bold', false,null)"]];
    return TRUE;
}

There is no error, it prints the NSLog and everything in the method works great except "stringByEvaluatingJavaScriptFromString" method.

But if I try to make text bold in another function, for example an IBAction method, works fine.

-(IBAction)boldClick:(id)sender
{
    [self.webView stringByEvaluatingJavaScriptFromString:[NSString stringWithFormat:@"document.execCommand('bold', false,null)"]];
}

Actually, this is my company's special application and this UIWebView will not show the web pages. I am using it to show some custom HTML pages. I need to make everything in "shouldStartLoadWithRequest" because I am trying to run an objective-c method from javascript.

UPDATE

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType{

    // Break apart request URL
    NSString *requestString = [[request URL] absoluteString];
    NSArray *components = [requestString componentsSeparatedByString:@":"];


    // Check for your protocol
    if ([components count]==3)
    {
        [self makeBoldText];
        return NO;
    }
    else
    {
        return TRUE;
    }
}

-(void)makeBoldText
{
    [self.webView stringByEvaluatingJavaScriptFromString:[NSString stringWithFormat:@"document.execCommand('bold', false,null)"]];
}

Michał Ciuba · Accepted Answer · 2013-07-15 12:09:07Z

2

The doc says that method webView:shouldStartLoadWithRequest: is sent before a web view begins loading a frame. After you return YES in this method, web view starts loading a request. So any javascript you execute will have no effect, because a new page will be loaded after your JS call.

You can probably use webViewDidFinishLoad: method to execute javascript after page finishes to load. Or if you want to trigger JS by clicking on a link, you can use shouldStartLoadWithRequest but return NO from it.

answered Jul 15, 2013 at 12:09

Michał Ciuba

7,9442 gold badges36 silver badges62 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

shouldStartLoadWithRequest doesn't run stringByEvaluatingJavaScriptFromString method

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related