在基于引导的主题上开发菜单时,我现在使用以下Walker:
\'walker\' => new Custom_Walker_Nav_Menu
class Custom_Walker_Nav_Menu extends Walker_Nav_Menu {
// add classes to ul sub-menus
function start_lvl( &$output, $depth ) {
// depth dependent classes
$indent = ( $depth > 0 ? str_repeat( "\\t", $depth ) : \'\' ); // code indent
$display_depth = ( $depth + 1); // because it counts the first submenu as 0
$classes = array(
\'sub-menu\',
( $display_depth % 2 ? \'menu-odd\' : \'menu-even\' ),
( $display_depth >=2 ? \'sub-sub-menu\' : \'\' ),
\'menu-depth-\' . $display_depth
);
$class_names = implode( \' \', $classes );
// build html
$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."\'");
if ( $depth == 0 && $has_children > 0 ) {
$output .= $indent . \'<li class="dropdown">\';
$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 ) .\'"\' : \'\';
$item_output = $args->before;
$item_output .= \'<a\'. $attributes .\' data-hover="dropdown" class="dropdown-toggle" role="button" aria-haspopup="true" aria-expanded="false">\';
$item_output .= $args->link_before . apply_filters( \'the_title\', $item->title, $item->ID ) . $args->link_after;
$item_output .= \'<span class="caret"></span></a>\';
$item_output .= $args->after;
} else {
$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 ) .\'"\' : \'\';
$item_output = $args->before;
$item_output .= \'<a\'. $attributes .\'>\';
$item_output .= $args->link_before . apply_filters( \'the_title\', $item->title, $item->ID ) . $args->link_after;
$item_output .= \'</a>\';
$item_output .= $args->after;
}
$output .= apply_filters( \'walker_nav_menu_start_el\', $item_output, $item, $depth, $args, $id );
}
}