MENU


Serialization

An object can be serialized to a string (and stored into a file). As serialize($o) is called, PHP first runs the magic function  __sleep(), which returns an array of the variable names to be serialized.
To restore a serialized string to an object, use unserialize($s). __wakeup() will be called after an object has been unserialized. 

<!DOCTYPE html>
<html>
<head></head>
<body><?php
class MyClass{
   public $a;
   public $b;
   public $c;
   public $arr=['hello','world'];
   function __sleep(){
      return ['a','b','arr'];
   }
   function __wakeup(){
      $this->c=50000;
   }
}
$o=new MyClass;
$o->a=100;
$o->b=2000;
$o->c=30000;
$s=serialize($o);
echo $s;

$o2=unserialize($s);
echo "<br />$o2->a";
echo "<br />$o2->b";
echo "<br />$o2->c";
?></body>
</html>

O:7:"MyClass":3:{s:1:"a";i:100;s:1:"b";i:2000;s:3:"arr";a:2:{i:0;s:5:"hello";i:1;s:5:"world";}}
100
2000
50000
__set_state($arr) is called when var_export($o) is called on an object. The latter is a function similar to var_dump(), which outputs the content of a variable, except that the output is PHP code.

RESETRUNFULL
<!DOCTYPE html>
<html>
<head></head>
<body><?php

class A{
    public $v1;
    public $v2;
    public static function __set_state($arr) {
        $obj = new A;
        $obj->v1 = $arr['v1'];
        $obj->v2 = $arr['v2'];
        return $obj;
    }
}
$a = new A;
$a->v1 = 5;
$a->v2 = 'Hello';
var_export($a);
eval('$b = ' . var_export($a, true) . ';');
echo "<br />";
var_export($b);

?></body>
</html>