How to pass data back to webpage? - windows-phone-8

Question

I am working on a WP8 application, containing the WebBrowser control in which I open a html page, containing javascript. The javascript contains the following function:
function send(data) {
windows.external.notify(data);
var xhr = new XMLHttpRequest();
xhr.open('GET', 'getresponse', false);
xhr.send(null);
var result = xhr.responseText;
if (result) {
return JSON.parse(result);
}
}
Basically this function calls the native C# side of the app, where I run some functions and I need to be able to return some data from the native side to the send function. I wanted to use an XMLHttpRequest for this, where my idea was to "intercept" the request url (in this case 'getresponse') and return the data I want by including it in the response.
Is this please possible on Windows Phone 8 using the WebBrowser control?
Once again, all I need to do is this:
Have a javascript function (in this case called "send") which connects to the native app (using windows.external.notify) and pass data back to this "send" function so that it can return it (and so that other JS function can use it).
Is this please possible? If not using the XMLHttpRequest, maybe using another technique?
Thank you all for your help!

Answer 1

You are looking for InvokeScript.
If you have full control over the page that is displayed inside the WebBrowser (e.g. the server is your's), you can define the JS-function to be called:
webBrowser.InvokeScript("yourJSFunction", "param1", "param2");
If you display a website from a foreign webserver you can inject JS like this (this uses jQuery):
webBrowser.InvokeScript("eval", "window.youInjectedFunction = function() {" +
"window.external.notify('and_notify_back');" +
"}; " +
"window.readyStateCheckInterval = setInterval(function() {" +
"window.external.notify('timer');" +
"if (document.readyState === 'complete') {" +
"clearInterval(window.readyStateCheckInterval);window.yourInjectedFuntion();" +
"}}, 100);" +
"");
I used the timer, as you can not be certain if the InvokeScript is called after the page is completely loaded.
If you can control the source, you should definitely go for option 1.