Implement new custom object serialization mechanism

[nikic]

RFC: https://wiki.php.net/rfc/custom_object_serialization

[nikic]

Merged as d373c11.

[nicolas-grekas]

For reference, I opened https://bugs.php.net/77866: internal Serializable classes should implement the new __(un)serialize methods, isn't it?

[yitam]

Not sure if this is the right place to ask about __wakeup() and __sleep() being removed from pdo pdo_dbh.c and pdo_stmt.c. In the aforementioned RFC it said "no particular pressing need to phase out __sleep() and __wakeup()". Please advice.

[caiofior]

I had an issue in a project made with Zend Framework 2.2 using session storage related to the class ArrayObject

namespace Zend\Stdlib;

use ArrayAccess;
use Countable;
use IteratorAggregate;
use Serializable;

/**
 * Custom framework ArrayObject implementation
 *
 * Extends version-specific "abstract" implementation.
 */
class ArrayObject implements IteratorAggregate, ArrayAccess, Serializable, Countable
{
    public function __serialize() {return $this->serialize();}
    public function __unserialize($data) {$this->unserialize($data);}

...

    /**
     * Unserialize an ArrayObject
     *
     * @param  string $data
     * @return void
     */
    public function unserialize($data)
    {
        $ar                        = unserialize($data);

In php greather than 7.3 the was a fatal error because the method _serialize must return an array.

The solution is a little involuted

namespace Zend\Stdlib;

use ArrayAccess;
use Countable;
use IteratorAggregate;
use Serializable;

/**
 * Custom framework ArrayObject implementation
 *
 * Extends version-specific "abstract" implementation.
 */
class ArrayObject implements IteratorAggregate, ArrayAccess, Serializable, Countable
{
    public function __serialize() {return (array)$this->serialize();}
    public function __unserialize($data) {$this->unserialize($data);}

...

    /**
     * Unserialize an ArrayObject
     *
     * @param  string $data
     * @return void
     */
    public function unserialize($data)
    {
        if (is_array($data)) {
            $data = reset($data);
        }
        $ar                        = unserialize($data);

Why __serialize() must return an array?
I suppose it returns a string.