PHP reflection (Reflection) usage sample code

What is reflection?

It refers to extending the analysis of PHP programs in the running state of PHP and exporting or extracting detailed information about classes, methods, properties, parameters, etc., including comments. This function of dynamically obtaining information and dynamically calling methods of objects is called reflection API. Reflection is an API for manipulating meta-models in the object-oriented paradigm. It is very powerful and can help us build complex and scalable applications.

Its uses include: automatically loading plug-ins, automatically generating documents, and can even be used to expand the PHP language.

The PHP reflection API consists of several classes that help us access the metadata of the program or interact with related annotations. With the help of reflection, we can obtain the methods implemented by the class, create an instance of the class (different from creating with new), call a method (also different from the regular call), pass parameters, and dynamically call the static methods of the class.

Reflection API is PHP's built-in OOP technology extension, including some classes, exceptions and interfaces. Used together, they can be used to help us analyze other classes, interfaces, methods, properties, methods and extensions. These oop extensions are called reflection.

This article mainly introduces the use examples of PHP reflection (Reflection). This article explains the use examples of ReflectionClass, ReflectionExtension, ReflectionFunction, ReflectionMethod, ReflectionObject, ReflectionParameter and other classes. Friends in need can refer to the following

PHP Reflection is used to obtain detailed information about classes, extensions, methods, functions, objects, parameters, and properties.
ReflectionClass class obtains class-related information, such as obtaining attributes, methods, document comments, etc.

<?php
 
class Person {
  /**
   * For the sake of demonstration, we"re setting this private
   */
  private $_allowDynamicAttributes = false;
 
  /** type=primary_autoincrement */
  protected $id = 0;
 
  /** type=varchar length=255 null */
  protected $name;
 
  /** type=text null */
  protected $biography;
 
  public function getId()
  {
    return $this->id;
  }
  public function setId($v)
  {
    $this->id = $v;
  }
  public function getName()
  {
    return $this->name;
  }
  public function setName($v)
  {
    $this->name = $v;
  }
  public function getBiography()
  {
    return $this->biography;
  }
  public function setBiography($v)
  {
    $this->biography = $v;
  }
}
 
//导出类
ReflectionClass::export(&#39;Person&#39;);
 
$r = new ReflectionClass(&#39;Person&#39;);
 
//获取所有属性
print_r($r->getProperties());
 
/**
 * 获取指定属性
 * ReflectionProperty::IS_STATIC
 * ReflectionProperty::IS_PUBLIC
 * ReflectionProperty::IS_PROTECTED
 * ReflectionProperty::IS_PRIVATE
 */
print_r($r->getProperties(ReflectionProperty::IS_PRIVATE));
 
//获取注释
print_r($r->getProperty(&#39;id&#39;)->getDocComment());
 
//获取方法
print_r($r->getMethods());

The ReflectionExtension class is used to obtain extension related information

$re = new ReflectionExtension('Reflection');
print_r($re->getClasses()); //扩展的所有类
print_r($re->getClassNames()); //扩展所有类名
 
$dom = new ReflectionExtension('mysql');
print_r($dom->getConstants());//扩展常量
print_r($dom->getDependencies());//该扩展依赖
print_r($dom->getFunctions());//扩展方法
print_r($dom->getINIEntries());//扩展ini信息
print_r($dom->getName());//扩展名称
print_r($dom->getVersion());//扩展版本
print_r($dom->info());//扩展信息
print_r($dom->isPersistent());//是否是持久扩展
print_r($dom->isTemporary()); //是否是临时扩展

ReflectionFunction class users obtain function-related information

$rf = new ReflectionFunction('array_merge');
 
foreach($rf->getParameters() as $item) {
  echo $item . PHP_EOL;
}

ReflectionMethod Class user obtains method related information

class Person {
 
  public $name;
 
  /**
   * get name of person
   */
  public function getName()
  {
    return $this->name;
  }
  public function setName($v)
  {
    $this->name = $v;
  }
}
 
$rm = new ReflectionMethod('Person', 'getName');
 
print_r($rm->isPublic());
print_r($rm->getDocComment());

ReflectionObject class is used to obtain object related information

class Person {
 
  public $name;
 
  public function __construct($name)
  {
    $this->name = $name;
  }
  
  public function getName()
  {
    return $this->name;
  }
  
  public function setName($v)
  {
    $this->name = $v;
  }
}
 
$a = new Person('a');
 
$ro = new ReflectionObject($a);
 
print_r($ro->getMethods());

ReflectionParameter Gets information about function or method parameters.

class Person {
 
  public $name;
 
  public function __construct($name)
  {
    $this->name = $name;
  }
 
  public function getName()
  {
    return $this->name;
  }
 
  public function setName($v)
  {
    $this->name = $v;
  }
}
 
$p = new ReflectionParameter(array('Person', 'setName'), 0);
 
print_r($p->getPosition()); //0
print_r($p->getName()); //v

ReflectionProperty Gets information about the properties of the class.

class Person {
 
  /** 测试 */
  public $name;
 
  public function __construct($name)
  {
    $this->name = $name;
  }
 
  public function getName()
  {
    return $this->name;
  }
 
  public function setName($v)
  {
    $this->name = $v;
  }
}
 
$p = new ReflectionProperty('Person', 'name');
 
print_r($p->getDocComment());

The above is the detailed content of PHP reflection (Reflection) usage sample code. For more information, please follow other related articles on the PHP Chinese website!