Add shortcode to Navigation block

Question

I am using a FSE theme and I need to add a short code in the navigation block. I Know there is no direct way to do that but i also have found this hook block_core_navigation_render_inner_blocks. Using that hook works if i try to add the mini-cart (WooCommerce) block but now i need to add a shortcode. The code is:

add_filter(
    'block_core_navigation_render_inner_blocks',
    function( $inner_blocks ) { 

        $menu_item = [
            'blockName'    => 'core/shortcode',         
            'attrs'        => [
                "text" => 'fk_cart_menu',               
            ],
            'innerBlocks'  => [],
            'innerHTML'    => '',
            'innerContent' => [],
        ];
        $inner_blocks->offsetSet( null, $menu_item );
        return $inner_blocks;
    }
);

I do not see the shortcode in the navigation block. Why? The shortcode exists, i also checked it with shortcode_exists() that returns true I also tried using [fk_car_menu] with parentesis, without any luck.

Answer 1

Despite the name, the shortcode block doesn't actually return a block; so the shortcode block cannot be rendered by block_core_navigation_render_inner_blocks as it only renders blocks. This is why in your test, the WooCommerce block worked but the shortcode block did not.

A possible way around this limitation is to register your own dynamic block that calls do_shortcode(...) in the render callback then use it in your add_filter(...) code, eg:

function so78080575_render_callback() {
  // return your shortcode, not echo..
  return do_shortcode( '[fk_cart_menu]' );
}

/* Register a simple, dynamic block */
function so78080575_register_block() {
  if ( !function_exists( 'register_block_type' ) ) {
    // return if block editor unavailable
    return;
  }
  register_block_type( 'so/78080575',
    $args = array(
      'title' => 'FK Cart Menu',
      'icon' => 'smiley',
      'render_callback' => 'so78080575_render_callback' // to render shortcode
    )
  );
}
add_action( 'init', 'so78080575_register_block' );


add_filter(
    'block_core_navigation_render_inner_blocks', // accepts only valid blocks
    function( $inner_blocks ) { 

        $menu_item = new WP_Block(['blockName' => 'so/78080575']);
        $inner_blocks->offsetSet( null, $menu_item );

        return $inner_blocks;
    }
);

Hopefully this gets you closer to what you are looking to achieve...