Question

I’m connecting to a webserver with a specific JavaScript. (Using HttpURLConnection atm)
What i need is a connection that makes it possible to manipulate a JavaScript function.
Afterwards i want to run the whole JavaScript again.

I want the following function always to return “new FlashSocketBackend()”

function createBackend() {
    if (flashSocketsWork) {
        return new FlashSocketBackend()
    } else {
        return new COMETBackend()
    }
}

Do i have to use HtmlUnit for this?
Whats the easiest way to connect, manipulate and re-run the script?

Thanks.

Answer 1

With HtmlUnit you indeed can do it.

Even though you can not manipulate an existing JS function, you can however execute what JavaScript code you wish on an existing page.

Example:

WebClient htmlunit = new WebClient();
HtmlPage page = htmlunit.getPage("http://www.google.com");
page = page.executeJavaScript("<JS code here>").getNewPage(); 

//manipulate the JS code and re-excute
page =  page.executeJavaScript("<manipulated JS code here>").getNewPage();

//manipulate the JS code and re-excute
page =  page.executeJavaScript("<manipulated JS code here>").getNewPage();

more:
http://www.aviyehuda.com/2011/05/htmlunit-a-quick-introduction/