Using __wakeup()

The topic of serializable objects would not be complete without the serialize() method counterpart--the  unserialize() method. If the serialize() method call triggers the object's __sleep() magic method, it is logical to expect there is a similar behavior for deserialization. Rightfully so, calling the unserialize() method upon a given object triggers its __wakeup() magic method.

The intended use of __wakeup() is to reestablish any resources that might have been lost during serialization and perform other reinitialization tasks.

Let's take a look at the following example:

<?php

class Backup
{
  protected $ftpClient;
  protected $ftpHost;
  protected $ftpUser;
  protected $ftpPass;

  public function __construct($host, $username, $password)
  {
    $this->ftpHost = $host;
    $this->ftpUser = $username;
    $this->ftpPass = $password;

    echo 'TEST!!!' . PHP_EOL;

    $this->connect();
  }

  public function connect()
  {
    $this->ftpClient = ftp_connect...