Show active menu item - wordpress

Question

i've a problem and don't know how solve it.
I need to display the dropdown menu of the current active menu.
I have the following code:
Class Description_Walker extends Walker_Nav_Menu {
function display_element( $element, &$children_elements, $max_depth, $depth=0, $args, &$output ) {
$id_field = $this->db_fields['id'];
if ( is_object( $args[0] ) ) {
$args[0]->has_children = ! empty( $children_elements[$element->$id_field] );
}
return parent::display_element( $element, $children_elements, $max_depth, $depth, $args, $output );
}
function start_lvl( &$output , $depth = 0 , $args = array() ) {
$indent = str_repeat( "\t", $depth );
$output .= "\n$indent<ul class=\"v-dropdown \">\n";
}
function start_el(&$output, $item, $depth = 0, $args = array(), $current_object_id = 0)
{
global $wp_query;
$indent = ( $depth ) ? str_repeat( "\t", $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 = ' '. esc_attr( $class_names ) . '';
$output .= $indent . '<li >';
$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 ) .'"' : '';
$prepend='';
$append = '';
$description = ! empty( $item->description ) ? '<span>'.esc_attr( $item->description ).'</span>' : '';
$item_output = $args->before;
if ( $args->has_children ) {
$append=" ▾";
$item_output .= '<a class="dropdown" data-hover="&nbsp">';
$item_output .= $args->link_before .$prepend.apply_filters( 'the_title', $item->title, $item->ID ).$append;
$item_output .= $description.$args->link_after;
$item_output .= '</a>';
$item_output .= $args->after;
} else {
$item_output .= '<a class="'.esc_attr( $class_names ).'" '. $attributes .' data-hover="&nbsp'.preg_replace(' ', $item->title).$append.'" >';
$item_output .= $args->link_before .$prepend.apply_filters( 'the_title', $item->title, $item->ID ).$append;
$item_output .= $description.$args->link_after;
$item_output .= '</a>';
$item_output .= $args->after;
}
$output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );
}
}
The website is this: http://fidesconsulta.ch/new_site
I need to show the ul class="v-dropdown" when the sub-menu is active.
Please help me.
Thank you.

Answer 1

Here's what I would do.
You could swap your <header class="relative"> for this:
<header class="relative <?php if ( $post->post_parent == '47' ) { ?>show-menu<?php } ?>" >
Replace the parent page ID where the '47' is. That is for if you have these pages set up with a parent id.
If not, you could do it this way, using the same <header class="relative"> setup.
<header class="relative <?php if ( is_page('services') || is_page('corporate-advisory') || is_page('audit-and-accounting') || is_page ('international-orientation-for-smi')) { ?>show-menu<?php } ?>" >
Then just add a css class like this in your css:
.show-menu ul li:nth-of-type(3) .v-dropdown {display: block; }
I set up a test locally, and I think either method will probably work for you. Let me know if I need to clarify.
Edit: I've added a psuedo-class in the css to target the first instance of '.v-dropdown' so that only the first menu opens.
Edit 2: I have updated the answer to reflect the correct css which helped AnmA solve the problem.