Question

i was working with wordpress website. i want to know is there any way to add thumbnail in wordpress nav menu 2nd level child pages. below is the structure for the wordpress nav menu

Menu First Level >>> Title

Menu Second Level >>> thumbnail with title

Menu Third Level >>> Title

Please check the screenshot.

in-short i want to make same functionality which i can control by wp menu option.
Thanks

Answer 1

Its very easy. i just found solution and it works for me

class Menu_With_Description extends Walker_Nav_Menu {
function start_el(&$output, $item, $depth, $args) {
    global $wp_query;

    $indent = ( $depth ) ? str_repeat( "", $depth ) : '';

    $class_names = $value = '';

    $classes = empty( $item->classes ) ? array() : (array) $item->classes;

    $class_names = join( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item ) );
    $class_names = ' class="' . esc_attr( $class_names ) . '"';

    $output .= $indent . '<li id="menu-item-'. $item->ID . '"' . $value . $class_names .'>';

    $attributes  = ! empty( $item->attr_title ) ? ' title="'  . esc_attr( $item->attr_title ) .'"' : '';
    $attributes .= ! empty( $item->target )     ? ' target="' . esc_attr( $item->target     ) .'"' : '';
    $attributes .= ! empty( $item->xfn )        ? ' rel="'    . esc_attr( $item->xfn        ) .'"' : '';
    $attributes .= ! empty( $item->url )        ? ' href="'   . esc_attr( $item->url        ) .'"' : '';

    // get user defined attributes for thumbnail images
    $attr_defaults = array( 'class' => 'nav_thumb' , 'alt' => esc_attr( $item->attr_title ) , 'title' => esc_attr( $item->attr_title ) );
    $attr = isset( $args->thumbnail_attr ) ? $args->thumbnail_attr : '';
    $attr = wp_parse_args( $attr , $attr_defaults );

    $item_output = $args->before;
     $item_output .= '<a'. $attributes .'>';
    if($depth == 1){
    // thumbnail image output
    $item_output .= ( isset( $args->thumbnail_link ) && $args->thumbnail_link ) ? '<a' . $attributes . '>' : '';
    $item_output .= apply_filters( 'menu_item_thumbnail' , ( isset( $args->thumbnail ) && $args->thumbnail ) ? get_the_post_thumbnail( $item->object_id , ( isset( $args->thumbnail_size ) ) ? $args->thumbnail_size : 'thumbnail' , $attr ) : '' , $item , $args , $depth );       
    $item_output .= ( isset( $args->thumbnail_link ) && $args->thumbnail_link ) ? '</a>' : '';
    }
    // menu link output

    $item_output .= $args->link_before . apply_filters( 'the_title', $item->title, $item->ID ) . $args->link_after;

    // menu description output based on depth
    //$item_output .= ( $args->desc_depth >= $depth ) ? '<br /><span class="sub">' . $item->description . '</span>' : '';

    // close menu link anchor
    $item_output .= '</a>';
    $item_output .= $args->after;

    $output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );
}
}
add_filter( 'wp_nav_menu_args' , 'my_add_menu_descriptions' );
function my_add_menu_descriptions( $args ) {
    $args['walker'] = new Menu_With_Description;
    $args['desc_depth'] = 1;
    $args['thumbnail'] = true;
    $args['thumbnail_link'] = false;
    $args['thumbnail_size'] = 'nav-thumb';
    $args['thumbnail_attr'] = array( 'class' => 'nav_thumb my_thumb' , 'alt' => 'test' , 'title' => 'test' );

    return $args;
}

just paste in functions.php, you can add thumbnails in the menu items.