我不是PHP开发人员,所以我想知道在PHP中使用显式getter/setter的优点和缺点是什么,在纯OOP风格中,带有私有字段(我喜欢的方式):
class MyClass {
private $firstField;
private $secondField;
public function getFirstField() {
return $this->firstField;
}
public function setFirstField($x) {
$this->firstField = $x;
}
public function getSecondField() {
return $this->secondField;
}
public function setSecondField($x) {
$this->secondField = $x;
}
}
或者只是公共字段:
class MyClass {
public $firstField;
public $secondField;
}
There are many ways to create sourcecode in a netbeans-convention. This is nice. It makes thinks such easyer === FALSE. Just use the traditionel, specially if you are not sure which one of the properties should be encapsuled and which one not. I know, it is a boi.... pla... code, but for debugging-works and many other thinks it is the better, clear way. Dont spend to much time with thousend of arts how to make simple getters and setters. You cannot implement too some design patterns like the demeter-rule and so on, if you use magics. In specific situation you can use magic_calls or for small, fast and clear solutions. Sure you could make solutions for design-patters in this way too, but why to make you live more difficult.
class MyClass {
private $firstField;
private $secondField;
private $thirdField;
public function __get( $name ) {
if( method_exists( $this , $method = ( 'get' . ucfirst( $name ) ) ) )
return $this->$method();
else
throw new Exception( 'Can\'t get property ' . $name );
}
public function __set( $name , $value ) {
if( method_exists( $this , $method = ( 'set' . ucfirst( $name ) ) ) )
return $this->$method( $value );
else
throw new Exception( 'Can\'t set property ' . $name );
}
public function __isset( $name )
{
return method_exists( $this , 'get' . ucfirst( $name ) )
|| method_exists( $this , 'set' . ucfirst( $name ) );
}
public function getFirstField() {
return $this->firstField;
}
protected function setFirstField($x) {
$this->firstField = $x;
}
private function getSecondField() {
return $this->secondField;
}
}
$obj = new MyClass();
echo $obj->firstField; // works
$obj->firstField = 'value'; // works
echo $obj->getFirstField(); // works
$obj->setFirstField( 'value' ); // not works, method is protected
echo $obj->secondField; // works
echo $obj->getSecondField(); // not works, method is private
$obj->secondField = 'value'; // not works, setter not exists
echo $obj->thirdField; // not works, property not exists
isset( $obj->firstField ); // returns true
isset( $obj->secondField ); // returns true
isset( $obj->thirdField ); // returns false
准备好了!
这篇文章不是专门关于__get和__set,而是关于__call,除了方法调用之外,它们是相同的思想。作为一种规则,我远离任何类型的允许重载的魔法方法,原因概述在评论和帖子中,然而,我最近遇到了一个第三方API,我使用了一个服务和一个子服务,例如:
http://3rdparty.api.com?service=APIService.doActionOne&apikey=12341234
这里重要的部分是,这个API除了子操作(在本例中为doActionOne)之外,其他内容都是相同的。这个想法是开发人员(我自己和其他使用这个类的人)可以通过名称调用子服务,而不是像这样:
$myClass->doAction(array('service'=>'doActionOne','args'=>$args));
我可以这样做:
$myClass->doActionOne($args);
对于硬编码来说,这只是大量的重复(这个例子非常类似于代码):
public function doActionOne($array)
{
$this->args = $array;
$name = __FUNCTION__;
$this->response = $this->executeCoreCall("APIService.{$name}");
}
public function doActionTwo($array)
{
$this->args = $array;
$name = __FUNCTION__;
$this->response = $this->executeCoreCall("APIService.{$name}");
}
public function doActionThree($array)
{
$this->args = $array;
$name = __FUNCTION__;
$this->response = $this->executeCoreCall("APIService.{$name}");
}
protected function executeCoreCall($service)
{
$cURL = new \cURL();
return $cURL->('http://3rdparty.api.com?service='.$service.'&apikey='.$this->api.'&'.http_build_query($this->args))
->getResponse();
}
但是使用神奇的__call()方法,我能够使用动态方法访问所有服务:
public function __call($name, $arguments)
{
$this->args = $arguments;
$this->response = $this->executeCoreCall("APIService.{$name}");
return $this;
}
这种动态调用数据返回的好处是,如果供应商添加了另一个子服务,我不必向类中添加另一个方法或创建扩展类等。我不确定这是否对任何人都有用,但我想我会展示一个例子,其中__set, __get, __call等可能是一个考虑的选项,因为主要函数是数据的返回。
编辑:
巧合的是,我在帖子发布几天后看到了这篇文章,它准确地概述了我的场景。这不是我指的API,但方法的应用是相同的:
我是否正确使用api ?