Google Plus One Button - How to add a callback?

Question

I have the google+ button being rendered on my site as follows:

In the JS:

    var po = document.createElement(\'script\'); po.type = \'text/javascr         


        

Answer 1

In addition to Jenny's answer you can also use a HTML5-valid +1 tag by setting the class attribute to g-plusone, and prefixing any button attributes with data- such as callback

From https://developers.google.com/+/web/+1button/