How to add class and element to <a>-tag in sub-menu of "wp_nav_menu" in WordPress?

i want to add a class to the `a` tag of an `sub-menu` and a `b` tag inside the link.

WordPress gives me this code:
```html
<li id="menu-item-72" class="menu-item menu-item-type-post_type menu-item-object-page dropdown menu-item-72"><a
href="#">Link</a>
<ul class="dropdown-menu"></ul>
```
And i want this:
```html
<li id="menu-item-72" class="menu-item menu-item-type-post_type menu-item-object-page dropdown menu-item-72"> <a
href="#" class="dropdown-toggle" data-toggle="dropdown">Link <b class="caret"></b></a>
<ul class="dropdown-menu"></ul>
```
Does anybody know a solution for that?

Look at this answer, it explains how to add custom HTML to the wordpress menus: [

[To see links please register here]

][1]

**EDIT:**

I've put together an example to fit your question. You can place it into **functions.php**. Note the comments, they explain where to add your custom code.

class Custom_Walker_Nav_Menu extends Walker_Nav_Menu {

function start_lvl(&$output, $depth) {
$indent = str_repeat("\t", $depth);
//$output .= "\n$indent<ul class=\"sub-menu\">\n";

// Change sub-menu to dropdown menu
$output .= "\n$indent<ul class=\"dropdown-menu\">\n";
}

function start_el ( &$output, $item, $depth = 0, $args = array(), $id = 0 ) {
// Most of this code is copied from original Walker_Nav_Menu
global $wp_query, $wpdb;
$indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';

$class_names = $value = '';

$classes = empty( $item->classes ) ? array() : (array) $item->classes;
$classes[] = 'menu-item-' . $item->ID;

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

$id = apply_filters( 'nav_menu_item_id', 'menu-item-'. $item->ID, $item, $args );
$id = strlen( $id ) ? ' id="' . esc_attr( $id ) . '"' : '';

$has_children = $wpdb->get_var("SELECT COUNT(meta_id)
FROM wp_postmeta
WHERE meta_key='_menu_item_menu_item_parent'
AND meta_value='".$item->ID."'");

$output .= $indent . '<li' . $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 ) .'"' : '';

// Check if menu item is in main menu
if ( $depth == 0 && $has_children > 0 ) {
// These lines adds your custom class and attribute
$attributes .= ' class="dropdown-toggle"';
$attributes .= ' data-toggle="dropdown"';
}

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

// Add the caret if menu level is 0
if ( $depth == 0 && $has_children > 0 ) {
$item_output .= ' <b class="caret"></b>';
}

$item_output .= '</a>';
$item_output .= $args->after;

$output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );
}

}

After you have this in place, you have to go to the point where your menu (`wp_nav_menu()`) is called. In the answer I've linked to, there's the full function call to `wp_nav_menu`. However you'll have to add this line: `'walker' => new Custom_Walker_Nav_Menu` to the arguments array, to use your custom walker object on that specific menu.

Hope you got it ;)

[1]:

[To see links please register here]

You can use this to check if there's a sub-menu:

$has_children = $wpdb->get_var("SELECT COUNT(meta_id)
FROM wp_postmeta
WHERE meta_key='_menu_item_menu_item_parent'
AND meta_value='".$item->ID."'");

then do simple checks

if ( $has_children > 0 ) {
// These lines adds your custom class and attribute
$attributes .= ' class="dropdown-toggle"';
$attributes .= ' data-toggle="dropdown"';
}

Remember to set **$wpdb** as global:

global $wp_query, $wpdb;

Tada~

Since Wordpress 3.6.0 you can use the nav_menu_link_attributes filter:

add_filter( 'nav_menu_link_attributes', 'add_class_to_items_link', 10, 3 );

function add_class_to_items_link( $atts, $item, $args ) {
// check if the item has children
$hasChildren = (in_array('menu-item-has-children', $item->classes));
if ($hasChildren) {
// add the desired attributes:
$atts['class'] = 'dropdown-toggle';
$atts['data-toggle'] = 'dropdown';
$atts['data-target'] = '#';
}
return $atts;
}

The <ul> tags unfortunately doesn't have a filter that we could use, so we'll need a walker:

class MY_Menu_Walker extends Walker_Nav_Menu {

public function start_lvl( &$output, $depth = 0, $args = array() ) {
$indent = str_repeat("\t", $depth);
$output .= "\n$indent<ul class=\"sub-menu dropdown-menu\">\n";
}

}

then add the walker option when calling the menu:

wp_nav_menu( array('walker' => new MY_Menu_Walker));

You can place it into functions.php.

class My_Walker_Nav_Menu extends Walker_Nav_Menu {
function display_element( $element, &$children_elements, $max_depth, $depth=0, $args, &$output ){
$GLOBALS['dd_children'] = ( isset($children_elements[$element->ID]) )? 1:0;
$GLOBALS['dd_depth'] = (int) $depth;
parent::display_element( $element, $children_elements, $max_depth, $depth, $args, $output );
}
function start_lvl(&$output, $depth) {
$indent = str_repeat("\t", $depth);
$output .= "\n$indent<ul class=\"dropdown-menu\">\n";
}
function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0 )
{
global $wp_query, $wpdb;
$indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';
$li_attributes = '';
$class_names = $value = '';
$classes = empty( $item->classes ) ? array() : (array) $item->classes;

//Add class and attribute to LI element that contains a submenu UL.
if ($args->has_children){
$classes[] = 'dropdown';
$li_attributes .= 'data-dropdown="dropdown"';
}
$classes[] = 'menu-item-' . $item->ID;
//If we are on the current page, add the active class to that menu item.
$classes[] = ($item->current) ? 'active' : '';
//Make sure you still add all of the WordPress classes.
$class_names = join( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item, $args ) );
$class_names = ' class="' . esc_attr( $class_names ) . '"';
$id = apply_filters( 'nav_menu_item_id', 'menu-item-'. $item->ID, $item, $args );
$id = strlen( $id ) ? ' id="' . esc_attr( $id ) . '"' : '';
$has_children = $wpdb->get_var(
$wpdb->prepare("
SELECT COUNT(*) FROM $wpdb->postmeta
WHERE meta_key = %s
AND meta_value = %d
", '_menu_item_menu_item_parent', $item->ID)
);
$output .= $indent . '<li' . $id . $value . $class_names .'>';
$output .= $indent . '<li' . $id . $value . $class_names . $li_attributes . '>';
//Add attributes to link element.
$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 ) .'"' : '';
// Check if menu item is in main menu

if ( $depth == 0 && $has_children > 0 ) {
// These lines adds your custom class and attribute
$attributes .= ' class="dropdown-toggle"';
$attributes .= ' data-toggle="dropdown"';
}
$item_output = $args->before;
$item_output .= '<a'. $attributes .'>';
$item_output .= $args->link_before . apply_filters( 'the_title', $item->title, $item->ID ) . $args->link_after;
// Add the caret if menu level is 0
if ( $depth == 0 && $has_children > 0 ) {
$item_output .= ' <b class="caret"></b>';
}
$item_output .= '</a>';
$item_output .= $args->after;
$output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );
}
}


Then in your template where you want to display this menu place this code.

<?php

if ( has_nav_menu( 'primary' ) ) {

$defaults = array(
'theme_location' => 'primary',
//'menu' => '',
'container' => 'ul',
'container_class' => '',
'container_id' => '',
'menu_class' => '',
'menu_id' => '',
'walker' => new My_Walker_Nav_Menu()
);

wp_nav_menu( $defaults );

}
?>
Using this I solved my problem.

Use This Code In Function.php

function add_menuclass($ulclass) {
return preg_replace('/<a /', '<a class="list-group-item"', $ulclass);
}
add_filter('wp_nav_menu','add_menuclass');