Getting a url from javascript form action to ios navigation

Question

I have a script like this:

var form = document.createElement("form");
form.setAttribute("action",url);
form.setAttribute("target",abc);

var win = window.open("","abc");
form.submit();

And I wrote createWebViewWithConfiguration method in the main view controller of my ios project to use window.open(), but there is no url in the first parameter of window.open() method so navigationAction.request.URL goes to about:blank. How can I get the form action url to my ios project?