class wp_Bootstrap_Menu extends Walker {
var $tree_type = array( 'post_type', 'taxonomy', 'custom' );
var $db_fields = array( 'parent' => 'menu_item_parent', 'id' => 'db_id' );
function start_lvl( &$output, $depth = 0, $args = array() ) {
if( $depth == 0 ){
$output .= '<ul class="dropdown-menu" role="menu">';
}else{
$output .= '<li class="divider"></li>';
}
}
function end_lvl( &$output, $depth = 0, $args = array() ) {
if( $depth == 0 ) $output .= "</ul>";
}
function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0 ) {
$caret = $glyphicon_icon = $item_output = '';
if( $depth > 0 && $item->description ) $item_output .= '<li role="presentation" class="dropdown-header">'.$item->description.'</li><li class="divider"></li>';
$atts = $atts_class = array();
$atts['target'] = ! empty( $item->target ) ? $item->target : '';
$atts['rel'] = ! empty( $item->xfn ) ? $item->xfn : '';
$atts['href'] = ! empty( $item->url ) ? $item->url : '';
$atts['title'] = ! empty( $item->title ) ? esc_attr( $item->attr_title ) : '';
$class_names = (array) get_post_meta( $item->ID, '_menu_item_classes', true );
//~ 判断第一个CSS类是否以 glyphicon 开头，是的话就当做 glyphicon 图标输出添加在链接文本前并删掉这个CSS类
if ( ! empty( $class_names[0] ) && strpos( esc_attr( $class_names[0] ) , 'glyphicon' ) !== false && strpos( esc_attr( $class_names[0] ) , 'glyphicon' ) == 0 ){
$glyphicon_icon = '<span class="glyphicon ' . esc_attr( $class_names[0] ) . '"></span> ';
unset($class_names[0]);
}
$is_parent = 0;
if ( $depth == 0 && ($args->depth)>=0 && in_array( 'menu-item-has-children', $item->classes ) ){
$class_names[] = 'dropdown';
$atts_class[] = 'dropdown-toggle';
$atts['data-toggle'] = 'dropdown';
$caret = ' <span class="caret"></span></a>';
$is_parent = 1;
}
if( empty( $item->url ) && empty($atts['data-toggle']) ) $atts_class[] = 'navbar-text';
if( $item->current || $item->current_item_ancestor || $item->current_item_parent ){
$class_names[] = 'active';
}
$class_names = join( ' ', apply_filters( 'nav_menu_css_class', array_filter( $class_names ), $item, $args ) );
$class_names = $class_names ? ' class="' . esc_attr( $class_names ) . '"' : '';
$item_output .= '<li' . $class_names .'>';
$atts['class'] = join('', $atts_class);
$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 .= ( $item->url || !empty($atts['data-toggle']) ) ? '<a'. $attributes .' itemprop="url">' : '<div'. $attributes .'>';
$item_output .= $args->link_before . $glyphicon_icon . apply_filters( 'the_title', $item->title, $item->ID ) . $caret . $args->link_after;
$item_output .= ( $item->url || !empty($atts['data-toggle']) ) ? '</a>' : '</div>';
$item_output .= $args->after;
$output .= $item_output;
}
function end_el( &$output, $item, $depth = 0, $args = array() ) {
$output .= "</li>";
}
}

。。
　　　-- 不是我不在乎你，而是你所谓的在乎让我承受不起。