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 swif

Answer 1

this worked fine for me:

func webView(_ webView: UIWebView, shouldStartLoadWith request: URLRequest, navigationType: UIWebViewNavigationType) -> Bool {
    if request.url?.scheme == "com.example.app" {
        print("I’m some JavaScript hoho")
    }

    return true
}

Note: you have to add "com.example.app" or whatever in your xcode project settings. Go to info, scroll down and find URL Scheme. Add your desired scheme there. Leave the other stuff the way it is. Then it should work just fine.

Answer 2

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)