function make_columns_sortable( $columns ) {

        // For each sortable column.
        foreach ( $this->sortable as $column => $values ) {

            // Make an array to merge into wordpress sortable columns.
            $sortable_columns[ $column ] = $values[0];
        }

        // Merge sortable columns array into wordpress sortable columns.
        $columns = array_merge( $sortable_columns, $columns );

        return $columns;
    }
function make_columns_sortable( $columns ) {

        // For each sortable column.
        foreach ( $this->sortable as $column => $values ) {

            // Make an array to merge into wordpress sortable columns.
            $sortable_columns[ $column ] = $values[0];
        }

        // Merge sortable columns array into wordpress sortable columns.
        $columns = array_merge( $sortable_columns, $columns );

        return $columns;
    }
function make_columns_sortable ( $ columns ) { // For each sortable column. foreach ( $ this -> sortable as $ column => $ values ) { // Make an array to merge into wordpress sortable columns. $ sortable_columns [ $ column ] = $ values [ 0 ] ; } // Merge sortable columns array into wordpress sortable columns. $ columns = array_merge ( $ sortable_columns , $ columns ) ; return $ columns ; }
Make columns sortable

Internal function that adds user defined sortable columns to WordPress default columns.

@param array $columns Columns to be sortable.
Make columns sortable