Open WooCommerce External Product Links in New Tab

/* WooCommerce External Product Links in New Tab */
add_filter( 'woocommerce_loop_add_to_cart_link',  'njengah_external_add_product_link' , 10, 2 );
remove_action( 'woocommerce_external_add_to_cart', 'woocommerce_external_add_to_cart', 30 );
add_action( 'woocommerce_external_add_to_cart', 'njengah_external_add_to_cart', 30 );
function njengah_external_add_product_link( $link ) {
          global $product;
          if ( $product->is_type( 'external' ) ) {
                    $link = sprintf( '<a rel="nofollow" href="%s" data-quantity="%s" data-product_id="%s" data-product_sku="%s" class="%s" target="_blank">%s</a>',
                    esc_url( $product->add_to_cart_url() ),
                    esc_attr( isset( $quantity ) ? $quantity : 1 ),
                    esc_attr( $product->id ),
                    esc_attr( $product->get_sku() ),
                    esc_attr( isset( $class ) ? $class : 'button product_type_external' ),
                    esc_html( $product->add_to_cart_text() )
                    );
          }
          return $link;
 }
function njengah_external_add_to_cart() {
                    global $product;
                    if ( ! $product->add_to_cart_url() ) {
                    return;
                    }
                    $product_url = $product->add_to_cart_url();
                    $button_text = $product->single_add_to_cart_text();

do_action( 'woocommerce_before_add_to_cart_button' ); ?>
 <p class="cart">
 <a href="<?php echo esc_url( $product_url ); ?>" rel="nofollow" class="single_add_to_cart_button                                                           button alt" target="_blank">  
                    <?php echo esc_html($button_text ); ?></a>
                    </p>
                    <?php do_action( 'woocommerce_after_add_to_cart_button' );
 }

Source: njengah

Above code adds target=”_blank” attribute to all the external links in WooCommerce so that the links will open in a New Tab. If you are running WooCommerce with external product links, you may use this feature.