我将WordPress从4.2.2升级到4.5.1，它破坏了我扩展Walker类的功能。Walker扩展：

class ReturnWalker extends Walker{

public $db_fields = array( \'parent\' => \'parent\', 
                           \'id\' => \'term_id\' );
public $show_all = FALSE;       

/*
*
*   @param array
*   @param object
*   @param int
*   @param
*   @return NULL
*/
public function start_el( &$output, $category, $depth = 0, $args = array(), $current_object_id = 0) {
    if( !is_array($output) )
        $output = array();

    $id = $this->db_fields[\'id\'];
    $parent = $this->db_fields[\'parent\'];

    if( $depth == 0 || (!$category->$parent) ){
        $output[$category->term_id] = $category;
    } else if( $depth > 0){
        $this->search( $output, $category->$parent, $category );
    }
}

/*
*
*   @param array
*   @param int 
*   @param object
*/
private function search( &$output, $key, $category){

    $id = $this->db_fields[\'id\'];
    $parent = $this->db_fields[\'parent\'];


    if( count($output) ){
        foreach( $output as $k => &$object){
            if( $k == $key ){
                $object->children[$category->term_id] = $category;
                return;
            } else if( isset($object->children[$key]) ){
                $this->search( $object->children, $category->$parent, $category );
            }
        }
    } else if( $this->show_all){
        $output[$category->$id] = $category;
    }
}

/*
*   sets the field names used for id and parent id
*   @param array(
*               \'id\' => string
*               \'parent\' => string
*          )
*   @return NULL
*/
public function setDbFields( array $db_fields){
    $this->db_fields = array_merge( $this->db_fields, $db_fields );
}
}

使用“get\\u the\\u terms（）”获取检索到的类别，并将其传递给walk方法：

$breadcrumbs = new ReturnWalker;
$category = get_the_terms( $post->ID, \'category\' );
$struct = $breadcrumbs->walk( $category, 0 );

经过仔细观察，我注意到$category现在是WP\\u Term对象的数组，WP\\u Term类是final。这破坏了扩展，因为它依赖于添加属性“children”的能力，但由于类是不可变的，因此不再可能。

最终的结果是，该功能将基于帖子所使用的自定义分类法构建URL和面包屑。有没有人能很好地解决这类问题？

Update -
创建一个模仿WP\\u Terms的类，并将get\\u Terms（）返回的对象复制到我的*\\u Terms类中。实例化类时传入返回的对象会命中构造函数，并生成我可以控制的属性的副本，而不用担心核心代码的更改：

                $categoryTerms = get_the_terms( $post->ID, \'category\' );

                foreach( $categoryTerms as $categoryTerm ){
                    $category[] = new MyTerm( $categoryTerm );
                }

                $breadcrumbs = new MyWalker;
                $struct = $breadcrumbs->walk( $category, 0, array());

            $categoryTerms = get_the_terms( $post->ID, \'category\' );

            foreach( $categoryTerms as $categoryTerm ){
                $category[] = new MyTerm( $categoryTerm );
            }

            $breadcrumbs = new MyWalker;
            $struct = $breadcrumbs->walk( $category, 0, array());