The __set_state Method
The __set_state
method is static and is called automatically when using the var_export
function on an object. It should return a new instance of the class with restored properties. This method is useful for object serialization and deserialization.
Syntax
public static function __set_state(array $properties): object
Example
Let's create a class and implement the __set_state
method in it:
<?php
class MyClass {
public $prop1;
public $prop2;
public function __construct($val1, $val2) {
$this->prop1 = $val1;
$this->prop2 = $val2;
}
public static function __set_state($array) {
return new self($array['prop1'], $array['prop2']);
}
}
$obj = new MyClass('a', 'b');
$exported = var_export($obj, true);
eval('$newObj = ' . $exported . ';');
var_dump($newObj);
?>
Code execution result:
object(MyClass)#2 (2) {
["prop1"]=> string(1) "a"
["prop2"]=> string(1) "b"
}
Example
Using __set_state
with private properties:
<?php
class PrivateClass {
private $secret;
public function __construct($value) {
$this->secret = $value;
}
public static function __set_state($array) {
$obj = new self($array['secret']);
return $obj;
}
}
$privateObj = new PrivateClass('12345');
$exported = var_export($privateObj, true);
eval('$newPrivateObj = ' . $exported . ';');
var_dump($newPrivateObj);
?>
Code execution result:
object(PrivateClass)#2 (1) {
["secret":"PrivateClass":private]=> string(5) "12345"
}
See Also
-
the
var_export
function,
which exports a variable to a string -
the
__sleep
method,
which is called before object serialization -
the
__wakeup
method,
which is called upon object deserialization