swift - Request from WKWebView -


i'm working vk api. want token when page finished load. how this? , how send token controller?

class loginviewcontroller: uiviewcontroller {      var _webview: wkwebview      override func viewdidload() {         super.viewdidload()          self.view.addsubview(_webview)          _webview.settranslatesautoresizingmaskintoconstraints(false)         let height = nslayoutconstraint(item: _webview, attribute: .height, relatedby: .equal, toitem: view, attribute: .height, multiplier: 1, constant: 0)         let width = nslayoutconstraint(item: _webview, attribute: .width, relatedby: .equal, toitem: view, attribute: .width, multiplier: 1, constant: 0)          self.view.addconstraints([height, width])          let url = nsurl(string: "https://oauth.vk.com/authorize?client_id=4876947&scope=audio&redirect_uri=https://oauth.vk.com/blank.html&display=mobile&v=5.30&response_type=token")         let request = nsurlrequest(url : url!)         _webview.loadrequest(request)     }      required init(coder adecoder: nscoder) {         self._webview = wkwebview(frame: cgrectzero)         super.init(coder: adecoder)     } }