Use Wicket to generate Google Analytics e-commerce tracking

I'm developing an e-commerce using Wicket to render pages. I have a "BasePage" with the main layout and, in my "thank you for purchasing" page, I want to add Google Analytics e-commerce tracking code. As reference, the JS code like this:

<script type="text/javascript>
  var _gaq = _gaq || [];
  _gaq.push(['_setAccount', 'UA-12345678-9']);
  _gaq.push(['_addTrans', '123', '', '12.56', '', '5.00']);
  _gaq.push(['_addItem', '123', 'sku-1', 'Product 1', 'Category X', '12.56', '1']);
  _gaq.push(['_addItem', '123', 'sku-2', 'Product 2', 'Category Y', '13.45', '1']);
  _gaq.push(['_trackTrans']);
  (function() {
    var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
    ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '开发者_开发问答.google-analytics.com/ga.js';
    var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
  })();
</script>

HTML code for cart and checkout was easy, but how can I generate this JS dynamically with Wicket?

Yes just to have a simple use of IHeaderContributor. Btw, are you using a framework for your wicket e-commerce? I have been trying to integrate one or two without much luck.

 class BasePage extends Page implements IHeaderContributor {
        public BasePage(String id){
                super(id);
        }
        @Override
        public void renderHead(IHeaderResponse response){
                //You might want renderOnLoadJavascript....
                // Btw, I didn't format your string for java, you need to add quotation
                // marks or put it as one line.
                response.renderJavascript("var _gaq = _gaq || [];
                         _gaq.push(['_setAccount', 'UA-12345678-9']);
                         _gaq.push(['_addTrans', '123', '', '12.56', '', '5.00']);
                         _gaq.push(['_addItem', '123', 'sku-1', 'Product 1', 'Category X', '12.56', '1']);
                         _gaq.push(['_addItem', '123', 'sku-2', 'Product 2', 'Category Y', '13.45', '1']);
                         _gaq.push(['_trackTrans']);
                         (function() {
                             var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
                             ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
                             var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
                         })();"
                );
        }
 }

I don't think Wicket gives you any help in building the javascript itself, you have to construct the JS string manually, and then either declare your <script> tag as a Label component and set the JS string as its model or use the IHeaderContributor interface.