src/Meta/Box.php
public function addSortableColumn($columns)
    {
        if ($this->data) {
            foreach ($this->data as $id => $field) {
                if ($field->admin_column_sortable) {
                    $columns[$id] = $field->label;
                }
            }
        }

        return $columns;
    }
public function addSortableColumn($columns)
    {
        if ($this->data) {
            foreach ($this->data as $id => $field) {
                if ($field->admin_column_sortable) {
                    $columns[$id] = $field->label;
                }
            }
        }

        return $columns;
    }
public function addSortableColumn ( $ columns ) { if ( $ this -> data ) { foreach ( $ this -> data as $ id => $ field ) { if ( $ field -> admin_column_sortable ) { $ columns [ $ id ] = $ field -> label ; } } } return $ columns ; }
Used to make all columns sortable.

@param  array $columns
@return array
Used to make all columns sortable .