BootstrapFormField::onBeforeRender
Adds the form-control class to *just* the formfield, not the holder.
This seems a bit of a hack, but addExtraClass() affects both the holder and the field, so that's not a realistic option. We can't have form-control on the wrapping div.
Signature
public function onBeforeRender(FormField
$field )
Parameters
$field
— FormField