Obtain object information using PHP's reflection_PHP tutorial-PHP Tutorial-php.cn

Obtain object information using PHP's reflection_PHP tutorial

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Release： 2016-07-13 10:33:46

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PHP5 adds a new feature: Reflection. This feature allows programmers to reverse-engineer class, interface, function, method and extension. Through PHP code, you can get all the information of an object and interact with it.

Suppose there is a class Person:

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;
        }
}

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Through ReflectionClass, we can get the following information of the Person class:

Constants
Properties Property Names
Method Method Names
Static Properties
Namespace Namespace
Whether the Person class is final or abstract

Just pass the class name "Person" to ReflectionClass:

$class = new ReflectionClass('Person');

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Get properties (Properties):

$properties = $class->getProperties();
foreach($properties as $property) {
    echo $property->getName()."n";
}
// 输出:
// _allowDynamicAttributes
// id
// name
// biography

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By default, ReflectionClass will get all properties, including private and protected ones. If you only want to get the private attribute, you need to pass an additional parameter:

$private_properties = $class->getProperties(ReflectionProperty::IS_PRIVATE);

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Available parameter list:

ReflectionProperty::IS_STATIC
ReflectionProperty::IS_PUBLIC
ReflectionProperty::IS_PROTECTED
ReflectionProperty::IS_PRIVATE

If you want to get both public and private properties, write like this: ReflectionProperty::IS_PUBLIC | ReflectionProperty::IS_PROTECTED

It shouldn’t feel strange.

The property name can be obtained through $property->getName(), and the comment written to the property can be obtained through getDocComment.

foreach($properties as $property) {
    if($property->isProtected()) {
        $docblock = $property->getDocComment();
        preg_match('/ type=([a-z_]*) /', $property->getDocComment(), $matches);
        echo $matches[1]."n";
    }
}
// Output:
// primary_autoincrement
// varchar
// text

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It’s a bit incredible. You can even get comments.

Get methods: Get all methods of the class through getMethods(). What is returned is an array of ReflectionMethod objects. No more demonstrations.

Finally, call the method in the class through ReflectionMethod.

$data = array("id" => 1, "name" => "Chris", "biography" => "I am am a PHP developer");
foreach($data as $key => $value) {
    if(!$class->hasProperty($key)) {
        throw new Exception($key." is not a valid property");
    }
 
    if(!$class->hasMethod("get".ucfirst($key))) {
        throw new Exception($key." is missing a getter");
    }
 
    if(!$class->hasMethod("set".ucfirst($key))) {
        throw new Exception($key." is missing a setter");
    }
 
    // Make a new object to interact with
    $object = new Person();
 
    // Get the getter method and invoke it with the value in our data array
    $setter = $class->getMethod("set".ucfirst($key));
    $ok = $setter->invoke($object, $value);
 
    // Get the setter method and invoke it
    $setter = $class->getMethod("get".ucfirst($key));
    $objValue = $setter->invoke($object);
 
    // Now compare
    if($value == $objValue) {
        echo "Getter or Setter has modified the data.n";
    } else {
        echo "Getter and Setter does not modify the data.n";
   }
}

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Interesting.