Php &引用；“提前返回”；最佳实践和干燥

我想知道，在某些情况下，是否有更好的方法“刹车”出方法。让我用代码更好地解释一下：

function execute($context)
{
    // some init actions

    $event = new BeforeOperationOne();
    $this->dispatch($event);
    if ($event->accessGranted()) {
        $context->setUser($this->user);
        // other repeated code

        return;
    }

    $result = $this->operationOne();

    // some other code

    $event = new BeforeOperationTwo();
    $this->dispatch($event);
    if ($event->accessGranted()) {
        $context->setUser($this->user);
        // other repeated code

        return;
    }

    // this is not important what is access checker, 
    // this is just to show that all following code uses data
    // computed in previous steps
    $accessChecker = new AccessChecker($result);
    $this->operationTwo(accessChecker);

    // some other code

    $event = new BeforeOperationThree();
    $this->dispatch($event);
    if ($event->accessGranted()) {
        $context->setUser($this->user);
        // other repeated code

        return;
    }

    $this->operationThree();

    // some other code
}

我们在这里重复了这个条件，当用户可以从事件访问时，在上下文中设置用户。我可以考虑的选择是：

丑陋的人做的时候（假）或去（我最好还是保持现在的样子）

将其提取到方法，并将条件更改为

if（！$this->handleEvent（$event，$context））{return；}

-这没有多大帮助，也不能认为更好的名称句柄不表示它返回了什么

为操作构建闭包数组，并通过检查循环它。我们可以假设所有事件类都是从带有accessgrated方法的公共类派生的。这可能很难看，因为一些操作需要来自前面“步骤”的数据，我必须将它们放在外面并传递它们

抛出并捕获用户有权访问的异常-另一个糟糕的解决方案

---

你有没有办法把它写得更好？

@Greg我在想这样的事情：

abstract class Handler
{
    protected $nextHandler = null;

    abstract public function Request($request);

    public function setNextHandler(Handler $handler)
    {
        $this->nextHandler = $handler;
    }

    protected function someOperations($event)
    {
        //i copied this section, so you must shape that
        $this->dispatch($event);
        if ($event->accessGranted()) {
            $context->setUser($this->user);
            // other repeated code

            return true;
        }

        return false;
    }
}

class BeforeOperationOneHandler extends Handler
{
    public function Request($request)
    {
          if ($this->someOperations(new BeforeOperationOne())) {
              return;
          }

          $result = $this->operationOne(); // shape this too

          return $this->nextHandler->Request($result);
    }
}

class BeforeOperationTwoHandler extends Handler
{
    public function Request($request)
    {
          if ($this->someOperations(new BeforeOperationTwo())) {
              return;
          }

          $accessChecker = new AccessChecker($result); // shape this too
          $result = $this->operationTwo(accessChecker);

          return $this->nextHandler->Request($result);
    }
}

class BeforeOperationThreeHandler extends Handler
{
    public function Request($request)
    {
          if ($this->someOperations(new BeforeOperationThree())) {
              return;
          }

          $result = $this->operationThree(); // shape this too

          return $this->nextHandler->Request($result);
    }
}

class DefaultHandler extends Handler
{
    public function Request($request)
    {
          // this is the last step
    }
}




function execute($context)
{
    // some init actions
    $beforeOperationOneHandler = new BeforeOperationOneHandler();
    $beforeOperationTwoHandler = new BeforeOperationTwoHandler();
    $beforeOperationThreeHandler = new BeforeOperationThreeHandler();
    $defaultHandler = new DefaultHandler();

    // set the sequence of the elements
    // BeforeOperationOneHandler > BeforeOperationTwoHandler > BeforeOperationThreeHandler> DefaultHandler
    $beforeOperationOneHandler->setNextHandler($beforeOperationTwoHandler);
    $beforeOperationTwoHandler->setNextHandler($beforeOperationThreeHandler);
    $beforeOperationThreeHandler->setNextHandler($defaultHandler);

    return $beforeOperationOneHandler->Request($some_init);
}

这只是快速编写的“责任链”模式，所以我无意中复制了您的一些代码片段

---

我希望这将引导您找到更好的解决方案

您的问题将得到许多基于意见的答案。但是，请看一看，并清理代码手册-第3章-功能。最后，正确的术语是“可能”责任链模式将是有用的？我试图实际做的是提供使用事件系统钩住方法的可能性，如果有可能提前完成方法，以避免用户访问不必要的繁重计算。感谢澄清。这让我重新思考解决方案。我走这边。