Buttons Bootstrap 3 icons

grek

How i can add icon to boostrap 3 buttons ?
'class_name'=> 'icon-pencil7', - change a not add <span>
if i add
'text' => '<i class="icon-pencil7">Compose</i>',
i see this as a code

kthorngren

Here is an example of what I use:

                buttons: [
                    {extend: 'copy',
                        text: '<i class="fa fa-copy"></i> Copy',
                    },

Kevin