When calling the wp_nav_menu()
function you can pass the <span>
tags in the link_before
y link_after
arguments:
wp_nav_menu(array('link_before' = > '<span>', 'link_after' => '</span>'));
To have differents attributes in the span for each menu item you may need to use a custom nav_walker. For example, the next custom Nav_Walker is the default from Wordpress, I've just modified it to add the <span>
with the data-hover
attribute:
//First, define the callback when displaying the menu
<nav>
<?php wp_nav_menu( array(
'container' => '',
'container_class' => '',
'theme_location' => 'topmenu',
'menu_class' => 'nav',
'fallback_cb' => '',
'walker' => new Custom_Walker(),
) );
?>
The custom nav walker, in this case Custom_Walker
must be in functions.php or included in it:
class Custom_Walker extends Walker_Nav_Menu {
/**
* @see Walker::$tree_type
* @since 3.0.0
* @var string
*/
var $tree_type = array( 'post_type', 'taxonomy', 'custom' );
/**
* @see Walker::$db_fields
* @since 3.0.0
* @todo Decouple this.
* @var array
*/
var $db_fields = array( 'parent' => 'menu_item_parent', 'id' => 'db_id' );
/**
* @see Walker::start_lvl()
* @since 3.0.0
*
* @param string $output Passed by reference. Used to append additional content.
* @param int $depth Depth of page. Used for padding.
*/
function start_lvl( &$output, $depth = 0, $args = array() ) {
$indent = str_repeat("\t", $depth);
$output .= "\n$indent<ul class=\"sub-menu\">\n";
}
/**
* @see Walker::end_lvl()
* @since 3.0.0
*
* @param string $output Passed by reference. Used to append additional content.
* @param int $depth Depth of page. Used for padding.
*/
function end_lvl( &$output, $depth = 0, $args = array() ) {
$indent = str_repeat("\t", $depth);
$output .= "$indent</ul>\n";
}
/**
* @see Walker::start_el()
* @since 3.0.0
*
* @param string $output Passed by reference. Used to append additional content.
* @param object $item Menu item data object.
* @param int $depth Depth of menu item. Used for padding.
* @param int $current_page Menu item ID.
* @param object $args
*/
function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0 ) {
$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_names ? ' class="' . esc_attr( $class_names ) . '"' : '';
$id = apply_filters( 'nav_menu_item_id', 'menu-item-'. $item->ID, $item, $args );
$id = $id ? ' id="' . esc_attr( $id ) . '"' : '';
$output .= $indent . '<li' . $id . $value . $class_names .'>';
$atts = array();
$atts['title'] = ! empty( $item->attr_title ) ? $item->attr_title : '';
$atts['target'] = ! empty( $item->target ) ? $item->target : '';
$atts['rel'] = ! empty( $item->xfn ) ? $item->xfn : '';
$atts['href'] = ! empty( $item->url ) ? $item->url : '';
$atts = apply_filters( 'nav_menu_link_attributes', $atts, $item, $args );
$attributes = '';
foreach ( $atts as $attr => $value ) {
if ( ! empty( $value ) ) {
$value = ( 'href' === $attr ) ? esc_url( $value ) : esc_attr( $value );
$attributes .= ' ' . $attr . '="' . $value . '"';
}
}
$item_output = $args->before;
$item_output .= '<a'. $attributes .'>';
$item_output .= $args->link_before;
// HERE are your <span> tags
$item_output .= '<span data-hover="'.esc_attr($item->title).'">';
$item_output .= apply_filters( 'the_title', $item->title, $item->ID );
$item_output .= '</span>';
$item_output .= $args->link_after;
$item_output .= '</a>';
$item_output .= $args->after;
$output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );
}
/**
* @see Walker::end_el()
* @since 3.0.0
*
* @param string $output Passed by reference. Used to append additional content.
* @param object $item Page data object. Not used.
* @param int $depth Depth of page. Not Used.
*/
function end_el( &$output, $item, $depth = 0, $args = array() ) {
$output .= "</li>\n";
}
}
Or maybe better (or not, I'm not sure because it needs a query foreach menu item via the get_post()
function if we want to run the filter only for the title of menus and not to all post titles), use the_title
filter hook (see toscho answer for a better way to use the_title
filter hook if you decide to use this filter instead the custom nav-walker):
function add_span_to_menu($title, $id) {
//Run this function only for nav_menu_item post types
$item = get_post( $id );
if($item->post_type != 'nav_menu_item') return;
$title = '<span data-hover="'.esc_attr($title).'">'.$title.'</span>';
return $title;
}
add_filter('the_title', 'add_span_to_menu', 10, 2);