view raw
Matrosov Alexander Matrosov Alexander - 6 months ago 52
iOS Question

Invoke method in objective c code from HTML code using UIWebView

I have .html file in my iOS app. HTML file has few div blocks with onClick methods.
When I tap on these blocks I invoke some javascript code in web view, but I need also know about these events in my source code.

For example when I tap on web element and onClick is called I need to invoke some method in the code e.g.

- (void)didTouchedWebElementWithId

Can I do this stuff. Thanks.


To call method of Objective-C in JS:

the below url helps in doing that

How to invoke Objective C method from Javascript and send back data to Javascript in iOS?

There is no way of executing, we make workaround by a navigation to other page and during the navigation, a webview delegate will watch for prefix of the navigation and execute the method we specified.


        <script type='text/javascript'>
            function getText()
                return document.getElementById('txtinput').value;
            function locationChange()
                window.location = 'ios:webToNativeCall';
    <body style='overflow-x:hidden;overflow-y:hidden;'>
        <h2 style = "font-size:16px;" align='center'>Hi Welcome to Webpage</h2>
        <p align='center' style = "font-size:12px;">Please Click the button after entering the text</p>
            <input type='text' style='width:90px;height:30px;' id='txtinput'/>
            <input type='button' style='width:90px;height:30px;' onclick='locationChange()' value='click me'>

Objective-C code

when you click button in html page the below delegate will fired and navigation cancelled because we return NO and respective method is called

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
    if ([[[request URL] absoluteString] hasPrefix:@"ios:"]) {

        // Call the given selector
        [self performSelector:@selector(webToNativeCall)];        
        // Cancel the location change
        return NO;
    return YES;

- (void)webToNativeCall
    NSString *returnvalue =  [self.webviewForHtml stringByEvaluatingJavaScriptFromString:@"getText()"];

    self.valueFromBrowser.text = [NSString stringWithFormat:@"From browser : %@", returnvalue ];