Multiple PHP warnings given when Tab Label is empty

This patch changes bootstrap_horizontal_tabs\Plugin\Field\FieldFormatter\BootstrapHorizontalTabs::viewElements so that it leaves $elements array empty if there is no data in field.

This approach looks promising! Assigning myself for the review...

Okay, I agree with the proposal that the $elements array should be an empty array if there are no $items. This is the same design as in the core Link field, whose viewElements method starts by setting $element = [];, and would effectively return the empty array if there are no items.

The proposed implementation in #6, however, would still populate some of the $elements array, namely

    $elements['#tabs_wrapper_attributes'] = new Attribute($tabs_wrapper_attributes);
    $elements['#content_wrapper_attributes'] = new Attribute($content_wrapper_attributes);

While this wouldn't result in any PHP warnings or unexpected content, it seems better to return a truly empty array.

Due to additional logic we have in the code, we can't precisely follow the implementation of the Link module, but the attached patch effectively returns the same result if there are no items.

Unassigning myself so someone else can review.

Updated patch in #9 does achieve result in a cleaner way.

Automatically closed - issue fixed for 2 weeks with no activity.