Add RTL Switcher in Menu Item

functions.php

function electro_wp_set_direction() {
    global $wp_locale, $wp_styles;

    if ( isset( $_GET['d'] ) ) {
        $direction = $_GET['d'] == 'rtl' ? 'rtl' : 'ltr';
        setcookie( 'electro_demo_direction', $direction, time()+3600 );
    } elseif( isset( $_COOKIE['electro_demo_direction'] ) ) {
        $direction = $_COOKIE['electro_demo_direction'];
        if ( false === $direction ) {
            $direction = isset( $wp_locale->text_direction ) ? $wp_locale->text_direction : 'ltr';
        }
    }

    if( isset( $direction ) ) {
        $wp_locale->text_direction = $direction;
        if ( ! is_a( $wp_styles, 'WP_Styles' ) ) {
            $wp_styles = new WP_Styles();
        }
        $wp_styles->text_direction = $direction;
    }
}

add_action( 'init', 'electro_wp_set_direction' );

function electro_rtl_switch_menu_nav_item( $items, $args ) {

    $available_menu_locations = apply_filters( 'electro_rtl_switch_menu_item_locations', array( 'topbar-right' ) );

    if ( in_array( $args->theme_location, $available_menu_locations ) && apply_filters( 'electro_rtl_switch_menu_item', true ) ) {
        if( is_rtl() ) {
            $url = add_query_arg( array( 'd' => 'ltr' ) );
            $title = esc_html__( 'Switch to LTR', 'electro' );
            $item_title = apply_filters( 'electro_rtl_switch_menu_item_title', '<i class="fa fa-refresh"></i>' . $title );
        } else {
            $url = add_query_arg( array( 'd' => 'rtl' ) );
            $title = esc_html__( 'Switch to RTL', 'electro' );
            $item_title = apply_filters( 'electro_rtl_switch_menu_item_title', '<i class="fa fa-refresh"></i>' . $title );
        }
        $items .= '<li class="menu-item"><a title="' . esc_attr( $title ) . '" href="' . esc_url( $url ) . '">' . $item_title . '</a></li>';
    }

    return $items;
}

add_filter( 'wp_nav_menu_items', 'electro_rtl_switch_menu_nav_item', 10, 2 );