我刚刚实现了http://wordpress.org/support/topic/wp_nav_menu-list-only-2nd-level-separate-submenu/page/2 为客户端实现主题时。当我在Wordpress堆栈上本地运行主题时，它的行为与预期一样，只显示父菜单项的子菜单项。当我将其部署到服务器时，它会显示所有菜单项，包括父菜单项和子菜单项，这显然不是期望的结果。我的代码如下：-
来自函数。php：-
class Custom_Walker_Nav_Sub_Menu extends Walker_Nav_Menu {
var $found_parents = array();
function start_el(&$output, $item, $depth, $args) {
global $wp_query;
//this only works for second level sub navigations
$parent_item_id = 0;
$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 = \' class="\' . esc_attr( $class_names ) . \'"\';
if ( ($item->menu_item_parent==0) && (strpos($class_names, \'current-menu-parent\')) ) {
$output.= \'
<li>\';
}
// Checks if the current element is in the current selection
if (strpos($class_names, \'current-menu-item\')
|| strpos($class_names, \'current-menu-parent\')
|| strpos($class_names, \'current-menu-ancestor\')
|| (is_array($this->found_parents) && in_array( $item->menu_item_parent, $this->found_parents )) ) {
// Keep track of all selected parents
$this->found_parents[] = $item->ID;
//check if the item_parent matches the current item_parent
if($item->menu_item_parent!=$parent_item_id){
$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 ) .\'"\' : \'\';
$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, $args );
}
}
}
function end_el(&$output, $item, $depth) {
// Closes only the opened li
if ( is_array($this->found_parents) && in_array( $item->ID, $this->found_parents ) ) {
$output .= "</li>\\n";
}
}
function end_lvl(&$output, $depth) {
$indent = str_repeat("\\t", $depth);
// If the sub-menu is empty, strip the opening tag, else closes it
if (substr($output, -22)=="<ul class=\\"sub-menu\\">\\n") {
$output = substr($output, 0, strlen($output)-23);
} else {
$output .= "$indent</ul>\\n";
}
}
}
从模板：-
<!-- start navigation -->
<div id="nav">
<div id="page-navigation">
<?php wp_nav_menu( array(\'theme_location\' => \'primary\', \'menu_class\' => \'nav-menu\', \'container\' => \'\', \'depth\' => 1, )); ?>
</div>
<div id="subnav">
<?php
$menu_args = array(
\'walker\' => new Custom_Walker_Nav_Sub_Menu(),
\'container\' => \'\',
\'menu_class\' => \'sister-pages\',
s);
wp_nav_menu($menu_args);
?>
</div>
</div>
<!-- end navigation -->
生成的源：-
<!-- start navigation -->
<div id="nav">
<div id="page-navigation">
<ul id="menu-main-menu" class="nav-menu">
<li id="menu-item-6931" class="menu-item menu-item-type-custom menu-item-object-custom current-menu-item current_page_item menu-item-home">
<a href="http://www.landlordreferencing.co.uk/">Our Products</a>
</li>
<li id="menu-item-6891" class="menu-item menu-item-type-custom menu-item-object-custom">
<a href="/wp-login.php?redirect_to=%2Fexisting-members%2F">Existing Members</a>
</li>
<li id="menu-item-6884" class="menu-item menu-item-type-custom menu-item-object-custom">
<a href="/business-directory/">Business Directory</a>
</li>
</ul>
</div>
<div id="subnav">
<ul id="menu-main-menu-1" class="sister-pages">
<li id="menu-item-6931" class="menu-item menu-item-type-custom menu-item-object-custom current-menu-item current_page_item menu-item-home">
<a href="http://www.landlordreferencing.co.uk/">Our Products</a>
<ul class="sub-menu">
<li style="display:none;"></li>
<li id="menu-item-6886" class="menu-item menu-item-type-post_type menu-item-object-page">
<a href="http://www.landlordreferencing.co.uk/home-2/">Overview</a>
</li>
<li id="menu-item-6888" class="menu-item menu-item-type-post_type menu-item-object-page">
<a href="http://www.landlordreferencing.co.uk/tenant-lifestyle-referencing/">Tenant Lifestyle Referencing</a>
</li>
<li id="menu-item-6920" class="menu-item menu-item-type-post_type menu-item-object-page">
<a href="http://www.landlordreferencing.co.uk/tenant-credit-referencing/">Tenant Credit Referencing</a>
</li>
<li id="menu-item-6889" class="menu-item menu-item-type-post_type menu-item-object-page">
<a href="http://www.landlordreferencing.co.uk/insurance/">Insurance</a>
</li>
</ul>
</li>
<li id="menu-item-6891" class="menu-item menu-item-type-custom menu-item-object-custom">
<a href="/wp-login.php?redirect_to=%2Fexisting-members%2F">Existing Members</a>
<ul class="sub-menu">
<li style="display:none;"></li>
<li id="menu-item-6912" class="menu-item menu-item-type-post_type menu-item-object-page">
<a href="http://www.landlordreferencing.co.uk/register-a-tenant/">Register a Tenant</a>
</li>
<li id="menu-item-6925" class="menu-item menu-item-type-post_type menu-item-object-page">
<a href="http://www.landlordreferencing.co.uk/tenant-search/">Tenant Lifestyle Search</a>
</li>
<li id="menu-item-6903" class="menu-item menu-item-type-post_type menu-item-object-page">
<a href="http://www.landlordreferencing.co.uk/access-experian/">Tenant Credit Search</a>
</li>
<li id="menu-item-6930" class="menu-item menu-item-type-custom menu-item-object-custom">
<a href="/questions/">Discuss</a>
</li>
</ul>
</li>
<li id="menu-item-6884" class="menu-item menu-item-type-custom menu-item-object-custom">
<a href="/business-directory/">Business Directory</a>
</li>
</ul>
</div>
</div>
<!-- end navigation -->
