<?php
trait Immutable {
private static $sealed = array();
public function __set($name, $value) {
if (isset(self::$sealed[spl_object_hash($this)])) {
throw new Exception("can't touch this, nah nah nuh nahhh");
}
$this->$name = $value;
}
public function __get($name) {
return $this->$name;
}
protected function finalize() {
self::$sealed[spl_object_hash($this)] = true;
// You could probably implement a __destruct to clean up and avoid leaking memory here,
// but who gaf anyway this is just an example
}
}
class ImmutableThingy {
use Immutable;
protected $foo;
public function __construct($foo)
{
$this->foo = $foo;
$this->finalize();
}
}
$thing = new ImmutableThingy("bar");
var_dump($thing, $thing->foo);
$thing->foo = 'baz';
var_dump($thing, $thing->foo);
object(ImmutableThingy)#1 (1) {
["foo":protected]=>
string(3) "bar"
}
string(3) "bar"
Fatal error: Uncaught Exception: can't touch this, nah nah nuh nahhh in /in/PmdKv:8
Stack trace:
#0 /in/PmdKv(40): ImmutableThingy->__set('foo', 'baz')
#1 {main}
thrown in /in/PmdKv on line 8
Process exited with code 255.
Output for 5.5.24 - 5.5.35, 5.6.8 - 5.6.28
object(ImmutableThingy)#1 (1) {
["foo":protected]=>
string(3) "bar"
}
string(3) "bar"
Fatal error: Uncaught exception 'Exception' with message 'can't touch this, nah nah nuh nahhh' in /in/PmdKv:8
Stack trace:
#0 /in/PmdKv(40): ImmutableThingy->__set('foo', 'baz')
#1 {main}
thrown in /in/PmdKv on line 8
Process exited with code 255.