Question

我有一个包含许多子类的基类，以及一个用于缓存函数结果的通用函数。在缓存函数中，我如何确定调用哪个子类？

class Base {
  public static function getAll() {
    return CacheService::cached(function() {
      // get objects from the database
    });
  }
}

class X extends Base {}
class Y extends Base {}
class Z extends Base {}

class CacheService {
  function cached($callback) {
    list(, $caller) = debug_backtrace();

    // $caller['class'] is always Base!
    // cannot use get_called_class as it returns CacheService!

    // see if function is in cache, otherwise do callback and store results
  }
}

X::getAll();
Z::getAll();

Answer 1

如果您使用的是PHP＆gt; = 5.3，则可以使用get_called_class()执行此操作。

修改：为了更清晰明了，必须在get_called_class()方法中使用Base::getAll()。当然，你必须告诉CacheService::cached()这个报告的类（添加方法参数将是最直接的方式）：

class Base {
  public static function getAll() {
    return CacheService::cached(get_called_class(), function() {
      // get objects from the database
    });
  }
}

class X extends Base {}
class Y extends Base {}
class Z extends Base {}

class CacheService {
  function cached($caller, $callback) {
    // $caller is now the child class of Base that was called

    // see if function is in cache, otherwise do callback and store results
  }
}

X::getAll();
Z::getAll();

Answer 2

尝试使用魔法常量__CLASS__

编辑：喜欢这样：

class CacheService {
  function cached($class, $callback) {
    // see if function is in cache, otherwise do callback and store results
  }
}


class Base {
  public static function getAll() {
    return CacheService::cached(__CLASS__, function() {
      // get objects from the database
    });
  }
}

进一步编辑：使用get_called_class：

class CacheService {
  function cached($class, $callback) {
    // see if function is in cache, otherwise do callback and store results
  }
}


class Base {
  public static function getAll() {
    return CacheService::cached(get_called_class(), function() {
      // get objects from the database
    });
  }
}

如何找出以前叫过哪个班级？

2 个答案: