wcml_is_variable_product

/**
 * This example is extracted from the Adventure Tours compatibility class in the WCML code. 
 */

add_filter( 'wcml_is_variable_product', 'is_variable_tour', 10, 2 );

function is_variable_tour( $is_variable, $product_id ){
    $var_tour_meta = get_post_meta( $product_id, '_variable_tour', true );

    if( $is_variable && $var_tour_meta == 'yes' ){
        $is_variable = true;
    }elseif( $var_tour_meta == 'no' ){
        $is_variable = false;
    }

    return $is_variable;
}