SugarCRM 7.x How to refresh a dashlet programmatically

Hello everyone, I'm used to search answers on this forum for a while, but for once, I have to ask my own question :)

On sugarcrm 7.6, I made a completely new dashlet, It was difficult but I did it.
Now I need to add a button in the dashlet to refresh it's content.

I guess I can use the loadData method embeded in the myDashlet.js file but how to ?

I tried to something in javascript with
App.***
But I'm not successful :(

Additionnaly, I would like to automatically set filter when I clicked on this button and before refreshing. Any idea ?