Online PHP editor | refs for BfmpQ

<?php class State { protected $foo; protected $bar; public function getFoo() { return $this->foo; } public function getBar() { return $this->bar; } public final function setFoo($foo) { $this->foo = $foo; } public final function setBar($bar) { $this->bar = $bar; } public final function transaction(callable $function) { $proxy = new StateProxy($this); if (call_user_func($function, $proxy)) { $proxy->commit(); } unset($proxy); } } class StateProxy extends State { protected $state; public function __construct(State $state) { $this->state = $state; } public function getFoo() { return parent::getFoo() ? : $this->state->getFoo(); } public function getBar() { return parent::getBar() ? : $this->state->getBar(); } public function commit() { $this->state->foo = $this->foo; $this->state->bar = $this->bar; } } $state = new State(); $state->setFoo('abc'); $state->setBar('123'); var_dump($state); $state->transaction(function(StateProxy $proxy) { $proxy->setFoo('def'); $proxy->setBar('456'); return true; }); var_dump($state); $state->transaction(function(StateProxy $proxy) { $proxy->setFoo('ghi'); $proxy->setBar('789'); return false; }); var_dump($state); $state = new State(); $state->setFoo('abc'); $state->setBar('123'); $state->transaction(function(StateProxy $proxy) { $proxy->transaction(function(StateProxy $proxy) { $proxy->transaction(function(StateProxy $proxy) { $proxy->transaction(function(StateProxy $proxy) { $proxy->setFoo('def'); $proxy->setBar('456'); return false; }); $proxy->transaction(function(StateProxy $proxy) { $proxy->setFoo('ghi'); $proxy->setBar('789'); return true; }); return true; }); $proxy->transaction(function(StateProxy $proxy) { $proxy->setFoo('jkl'); $proxy->setBar('012'); return false; }); return true; }); return true; }); var_dump($state);