生成树 Tree [ 2.0 版本 ]

<?php

namespace core\common\utils;

use JsonSerializable;
use yii\base\BaseObject;

/**
*

• @property int|null $id 节点Id
• @property int|null $pid 父节点Id
• @property int|null $sort 排序
• @property array|null $children 子节点（子树）
• @property array $data

• @property string|null $dataType
  */
  class Node extends BaseObject implements JsonSerializable {
  private $_id;
  private $_pid;
  private $_sort;
  private $_children = [];
  private $_data;
  private $_dataType;

  public function getId(){

   return $this->_id;
  

  }
  public function setId($value){

   $this->_id = $value;
  

  }
  public function getPid(){

   return $this->_pid;
  

  }
  public function setPid($value){

   $this->_pid = $value;
  

  }
  public function getSort(){

   return $this->_sort;
  

  }
  public function setSort($value){

   $this->_sort = $value;
  

  }
  public function getChildren()
  {

   return $this->_children;
  

  }
  public function setChildren($value){

   if (is_array($value))
       $this->_children = $value;
   else{
       if ( !empty($value) ){
           $this->_children[] = $value;
       }else{
           $this->_children = [];
       }
   }
  

  }
  public function getData()
  {

   return $this->_data;
  

  }
  public function setData($value)
  {

   $this->_data = $value;
  

  }
  public function getDataType()
  {

   return $this->_dataType;
  

  }
  public function setDataType($value)
  {

   $this->_dataType = $value;
  

  }
  // if (method_exists($this, $getter))
  // if (property_exists($this, $getter))
  // canGetProperty() 或 canSetProperty() 
  public function __get($name){

   if ( isset($this->_data[$name]) )
       return $this->_data[$name];
   //$name=root  调用 getRoot
   return parent::__get($name); // TODO: Change the autogenerated stub
  

  }

  public function __set($name, $value)
  {

   if ( isset($this->_data[$name]) )
       $this->_data[$name] = $value;
   else
       parent::__set($name, $value); // TODO: Change the autogenerated stub
  

  }

  // 实现的抽象类方法，指定需要被序列化JSON的数据
  public function jsonSerialize() {

  $data = [];
  /*
   foreach ($this as $key=>$val){
       if ($val !== null) {
           $data[$key] = $val;
       }
   }*/
   $data['id'] = $this->_id;
   $data['pid'] = $this->_pid;
   $data['data'] = $this->_data;
   $data['children'] = $this->_children;
   return $data;
  

  }
  }

class Tree extends BaseObject{

private $_tree       = [];
private $_tree_index = [];
private $_tree_dataType = null;
private $_id_tag  = null;
private $_pid_tag = null;

public function __construct($id_tag= null,$pid_tag= null,$config = []){

    $this->_id_tag  = $id_tag ?? 'id';
    $this->_pid_tag = $pid_tag ?? 'pid';

    parent::__construct($config);
}

public function create($list){
    if ( empty($this->tree_dataType) )
        $this->_tree_dataType = get_class($list[0]);

    if ($this->_tree_dataType == get_class($list[0])){
        foreach ($list as $key => $value){
            $node   = new Node();
            $node->id   = $value[$this->_id_tag];
            $node->pid  = $value[$this->_pid_tag];
            $node->sort = $value['sort'];
            $node->data = $value->attributes;
            $node->dataType = $this->_tree_dataType;
            $node->children = $this->getAllChildren($node->id);
            $this->_tree_index[$node->id] = $node;

            $p_node = $this->getFatherNode($node->id);

            if ( !empty( $p_node ) ){
                $p_node->children = $node;
            }else if ( empty( $p_node ) && empty($node->pid) ){
                // 没有父节
                $this->_tree[] = $node;
            }
            unset($list[$key]);
        }
    }else{
        throw new Exception("数据类型不一致");
    }
    $this->sort($this->_tree);
    return $this->_tree;
}

public function getFindRoot($id):?Node{
    if ( !empty( $id ) ){
        $node = self::getFatherNode($id);
        if ( !empty($node->pid) ){
            return self::getFindRoot($node->id);
        }
        else{
            return $node;
        }
    }
    return null;
}
public function getNode($id):?Node{
    $node = $this->_tree_index[$id];
    if ( !empty($node))
        return $node;
    return null;
}
public function getFatherNode($id):?Node{
    if ( !empty( $id ) ){
        $node = self::getNode($id);
        if ( isset($node) ){
            $pid  = $node->pid;
            if ( !empty( $pid ) )
                return self::getNode($pid);
        }
    }
    return null;
}
public function getAllChildren($id){
    $temp = [];
    foreach ($this->_tree_index as $key => $value){
        if ( $value->pid == $id ){
            $temp[] = $value;
        }
    }
    return $temp;
}

public function sort(&$tree){
    foreach ($tree as $key => $item){
        if ( !empty( $item->children )){
            $tm = $item->children;
            self::sort($tm);
            $item->children = $tm;
        }
    }
    return Sort::property_sort($tree,Sort::SORT_ASC,'sort');
}

}

使用
$result = $goods->category->findAll();
$tree = new Tree('classId','classPId');
$_Json->data = $tree->create($result['data']);
// $result['data'] 是一个 array|ActiveRecord[]