Communication with Iframe

Hello,

I use Vaadin 7.5 and an Iframe in my application ( see https://vaadin.com/forum#!/thread/11006414).
The communication from Vaadin-Application to Iframe works well with JavaScript.
What ist the best way , to communicate from iframe to Vaadin-application?
Example: I click a Button in my Iframe and then my table in the Vaadin-application is filled with parameters from Iframe.

Thanks
Patrick