Call swift function with javascript using UIWebview

Question

I apologize if this has been asked but I was unable to find any answer or solution. I am looking to call a JavaScript function from a "UIWebView" and listen for it in swift. Any example I have found uses "WKWebView". There has to be an easy way to listen to a JavaScript function like the below:

// HTML / JS
<div id ="myDiv" onclick="listenInSwift()">myItem</div>

Is this possible with a UIWebView? Thanks all!

Answer 1

Implement listenInSwift like this:

function listenInSwift() {
    window.location = 'yoururlscheme://somehost?greeting=hello'
} 

Then listen for this URL with this code in your UIWebViewDelegate class:

func webView(_ webView: UIWebView, shouldStartLoadWithRequest request: NSURLRequest, navigationType navigationType: UIWebViewNavigationType) -> Bool {
    if request.URL.scheme == 'yoururlscheme' {
        print('Hello JavaScript...')
    }
}

Don't forget to register your URL Scheme (in this case 'yoururlscheme') in Xcode.

To load a local file in the web view, try this:

let baseURL = NSURL.fileURLWithPath(NSBundle.mainBundle().bundlePath);
let relativePath = "www/\(file)"
let fileURL = NSURL(string: relativePath, relativeToURL: baseURL);
let URLRequest = NSURLRequest(URL: fileURL!);
webView.loadRequest(URLRequest)