If your html tag looks like this:
var this_data = $(this).attr('data-my-data');
I like to use these in click functions
<script>
$(document).ready(function() { //12PM DOC READY
$( ".mybutton" ).click(function() {
var this_data = $(this).attr('data-my-data');
alert(this_data);
});
}); //12PM DOC READY
</script>
This will alert “some cool data”