text: <?php
  // +----------------------------------------------------------------------
  // | ThinkPHP [ WE CAN DO IT JUST THINK ]
  // +----------------------------------------------------------------------
  // | Copyright (c) 2006~2018 http://thinkphp.cn All rights reserved.
  // +----------------------------------------------------------------------
  // | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
  // +----------------------------------------------------------------------
  // | Author: liu21st <liu21st@gmail.com>
  // +----------------------------------------------------------------------
  
  namespace think\model\concern;
  
  use think\Container;
  use think\Loader;
  
  /**
   * 模型事件处理
   */
  trait ModelEvent
  {
      /**
       * 模型回调
       * @var array
       */
      private static $event = [];
  
      /**
       * 模型事件观察
       * @var array
       */
      protected static $observe = ['before_write', 'after_write', 'before_insert', 'after_insert', 'before_update', 'after_update', 'before_delete', 'after_delete', 'before_restore', 'after_restore'];
  
      /**
       * 绑定模型事件观察者类
       * @var array
       */
      protected $observerClass;
  
      /**
       * 是否需要事件响应
       * @var bool
       */
      private $withEvent = true;
  
      /**
       * 注册回调方法
       * @access public
       * @param  string   $event    事件名
       * @param  callable $callback 回调方法
       * @param  bool     $override 是否覆盖
       * @return void
       */
      public static function event($event, $callback, $override = false)
      {
          $class = static::class;
  
          if ($override) {
              self::$event[$class][$event] = [];
          }
  
          self::$event[$class][$event][] = $callback;
      }
  
      /**
       * 清除回调方法
       * @access public
       * @return void
       */
      public static function flushEvent()
      {
          self::$event[static::class] = [];
      }
  
      /**
       * 注册一个模型观察者
       *
       * @param  object|string  $class
       * @return void
       */
      public static function observe($class)
      {
          self::flushEvent();
  
          foreach (static::$observe as $event) {
              $eventFuncName = Loader::parseName($event, 1, false);
  
              if (method_exists($class, $eventFuncName)) {
                  static::event($event, [$class, $eventFuncName]);
              }
          }
      }
  
      /**
       * 当前操作的事件响应
       * @access protected
       * @param  bool $event  是否需要事件响应
       * @return $this
       */
      public function withEvent($event)
      {
          $this->withEvent = $event;
          return $this;
      }
  
      /**
       * 触发事件
       * @access protected
       * @param  string $event  事件名
       * @return bool
       */
      protected function trigger($event)
      {
          $class = static::class;
  
          if ($this->withEvent && isset(self::$event[$class][$event])) {
              foreach (self::$event[$class][$event] as $callback) {
                  $result = Container::getInstance()->invoke($callback, [$this]);
  
                  if (false === $result) {
                      return false;
                  }
              }
          }
  
          return true;
      }
  
      /**
       * 模型before_insert事件快捷方法
       * @access protected
       * @param callable  $callback
       * @param bool      $override
       */
      protected static function beforeInsert($callback, $override = false)
      {
          self::event('before_insert', $callback, $override);
      }
  
      /**
       * 模型after_insert事件快捷方法
       * @access protected
       * @param callable  $callback
       * @param bool      $override
       */
      protected static function afterInsert($callback, $override = false)
      {
          self::event('after_insert', $callback, $override);
      }
  
      /**
       * 模型before_update事件快捷方法
       * @access protected
       * @param callable  $callback
       * @param bool      $override
       */
      protected static function beforeUpdate($callback, $override = false)
      {
          self::event('before_update', $callback, $override);
      }
  
      /**
       * 模型after_update事件快捷方法
       * @access protected
       * @param callable  $callback
       * @param bool      $override
       */
      protected static function afterUpdate($callback, $override = false)
      {
          self::event('after_update', $callback, $override);
      }
  
      /**
       * 模型before_write事件快捷方法
       * @access protected
       * @param callable  $callback
       * @param bool      $override
       */
      protected static function beforeWrite($callback, $override = false)
      {
          self::event('before_write', $callback, $override);
      }
  
      /**
       * 模型after_write事件快捷方法
       * @access protected
       * @param callable  $callback
       * @param bool      $override
       */
      protected static function afterWrite($callback, $override = false)
      {
          self::event('after_write', $callback, $override);
      }
  
      /**
       * 模型before_delete事件快捷方法
       * @access protected
       * @param callable  $callback
       * @param bool      $override
       */
      protected static function beforeDelete($callback, $override = false)
      {
          self::event('before_delete', $callback, $override);
      }
  
      /**
       * 模型after_delete事件快捷方法
       * @access protected
       * @param callable  $callback
       * @param bool      $override
       */
      protected static function afterDelete($callback, $override = false)
      {
          self::event('after_delete', $callback, $override);
      }
  
      /**
       * 模型before_restore事件快捷方法
       * @access protected
       * @param callable  $callback
       * @param bool      $override
       */
      protected static function beforeRestore($callback, $override = false)
      {
          self::event('before_restore', $callback, $override);
      }
  
      /**
       * 模型after_restore事件快捷方法
       * @access protected
       * @param callable  $callback
       * @param bool      $override
       */
      protected static function afterRestore($callback, $override = false)
      {
          self::event('after_restore', $callback, $override);
      }
  }
  